Maximal intended velocity training induces greater gains in bench press performance than deliberately slower half-velocity training.

PubMed

González-Badillo, Juan José; Rodríguez-Rosell, David; Sánchez-Medina, Luis; Gorostiaga, Esteban M; Pareja-Blanco, Fernando

2014-01-01

The purpose of this study was to compare the effect on strength gains of two isoinertial resistance training (RT) programmes that only differed in actual concentric velocity: maximal (MaxV) vs. half-maximal (HalfV) velocity. Twenty participants were assigned to a MaxV (n = 9) or HalfV (n = 11) group and trained 3 times per week during 6 weeks using the bench press (BP). Repetition velocity was controlled using a linear velocity transducer. A complementary study (n = 10) aimed to analyse whether the acute metabolic (blood lactate and ammonia) and mechanical response (velocity loss) was different between the MaxV and HalfV protocols used. Both groups improved strength performance from pre- to post-training, but MaxV resulted in significantly greater gains than HalfV in all variables analysed: one-repetition maximum (1RM) strength (18.2 vs. 9.7%), velocity developed against all (20.8 vs. 10.0%), light (11.5 vs. 4.5%) and heavy (36.2 vs. 17.3%) loads common to pre- and post-tests. Light and heavy loads were identified with those moved faster or slower than 0.80 m · s(-1) (∼ 60% 1RM in BP). Lactate tended to be significantly higher for MaxV vs. HalfV, with no differences observed for ammonia which was within resting values. Both groups obtained the greatest improvements at the training velocities (≤ 0.80 m · s(-1)). Movement velocity can be considered a fundamental component of RT intensity, since, for a given %1RM, the velocity at which loads are lifted largely determines the resulting training effect. BP strength gains can be maximised when repetitions are performed at maximal intended velocity.

A comparison of the effects of 6 weeks of traditional resistance training, plyometric training, and complex training on measures of strength and anthropometrics.

PubMed

MacDonald, Christopher J; Lamont, Hugh S; Garner, John C

2012-02-01

Complex training (CT; alternating between heavy and lighter load resistance exercises with similar movement patterns within an exercise session) is a form of training that may potentially bring about a state of postactivation potentiation, resulting in increased dynamic power (Pmax) and rate of force development during the lighter load exercise. Such a method may be more effective than either modality, independently for developing strength. The purpose of this research was to compare the effects of resistance training (RT), plyometric training (PT), and CT on lower body strength and anthropometrics. Thirty recreationally trained college-aged men were trained using 1 of 3 methods: resistance, plyometric, or complex twice weekly for 6 weeks. The participants were tested pre, mid, and post to assess back squat strength, Romanian dead lift (RDL) strength, standing calf raise (SCR) strength, quadriceps girth, triceps surae girth, body mass, and body fat percentage. Diet was not controlled during this study. Statistical measures revealed a significant increase for squat strength (p = 0.000), RDL strength (p = 0.000), and SCR strength (p = 0.000) for all groups pre to post, with no differences between groups. There was also a main effect for time for girth measures of the quadriceps muscle group (p = 0.001), the triceps surae muscle group (p = 0.001), and body mass (p = 0.001; post hoc revealed no significant difference). There were main effects for time and group × time interactions for fat-free mass % (RT: p = 0.031; PT: p = 0.000). The results suggest that CT mirrors benefits seen with traditional RT or PT. Moreover, CT revealed no decrement in strength and anthropometric values and appears to be a viable training modality.

Vitamin C and E supplementation alters protein signalling after a strength training session, but not muscle growth during 10 weeks of training.

PubMed

Paulsen, G; Hamarsland, H; Cumming, K T; Johansen, R E; Hulmi, J J; Børsheim, E; Wiig, H; Garthe, I; Raastad, T

2014-12-15

This study investigated the effects of vitamin C and E supplementation on acute responses and adaptations to strength training. Thirty-two recreationally strength-trained men and women were randomly allocated to receive a vitamin C and E supplement (1000 mg day(-1) and 235 mg day(-1), respectively), or a placebo, for 10 weeks. During this period the participants' training involved heavy-load resistance exercise four times per week. Muscle biopsies from m. vastus lateralis were collected, and 1 repetition maximum (1RM) and maximal isometric voluntary contraction force, body composition (dual-energy X-ray absorptiometry), and muscle cross-sectional area (magnetic resonance imaging) were measured before and after the intervention. Furthermore, the cellular responses to a single exercise session were assessed midway in the training period by measurements of muscle protein fractional synthetic rate and phosphorylation of several hypertrophic signalling proteins. Muscle biopsies were obtained from m. vastus lateralis twice before, and 100 and 150 min after, the exercise session (4 × 8RM, leg press and knee-extension). The supplementation did not affect the increase in muscle mass or the acute change in protein synthesis, but it hampered certain strength increases (biceps curl). Moreover, increased phosphorylation of p38 mitogen-activated protein kinase, Extracellular signal-regulated protein kinases 1 and 2 and p70S6 kinase after the exercise session was blunted by vitamin C and E supplementation. The total ubiquitination levels after the exercise session, however, were lower with vitamin C and E than placebo. We concluded that vitamin C and E supplementation interfered with the acute cellular response to heavy-load resistance exercise and demonstrated tentative long-term negative effects on adaptation to strength training. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Effects of 18-week in-season heavy-resistance and power training on throwing velocity, strength, jumping, and maximal sprint swim performance of elite male water polo players.

PubMed

Ramos Veliz, Rafael; Requena, Bernardo; Suarez-Arrones, Luis; Newton, Robert U; Sáez de Villarreal, Eduardo

2014-04-01

We examined the effects of 18 weeks of strength and high-intensity training on key sport performance measures of elite male water polo (WP) players. Twenty-seven players were randomly assigned to 2 groups, control (in-water training only) and strength group, (strength training sessions [twice per week] + in-water training). In-water training was conducted 5 d·wk. Twenty-meter maximal sprint swim, maximal dynamic strength 1-repetition maximum (1RM) for upper bench press (BP) and lower full squat (FS) body, countermovement jump (CMJ), and throwing velocity were measured before and after the training. The training program included upper and lower body strength and high-intensity exercises (BP, FS, military press, pull-ups, CMJ loaded, and abs). Baseline-training results showed no significant differences between the groups in any of the variables tested. No improvement was found in the control group; however, meaningful improvement was found in all variables in the experimental group: CMJ (2.38 cm, 6.9%, effect size [ES] = 0.48), BP (9.06 kg, 10.53%, ES = 0.66), FS (11.06 kg, 14.21%, ES = 0.67), throwing velocity (1.76 km·h(-1), 2.76%, ES = 0.25), and 20-m maximal sprint swim (-0.26 seconds, 2.25%, ES = 0.29). Specific strength and high-intensity training in male WP players for 18 weeks produced a positive effect on performance qualities highly specific to WP. Therefore, we propose modifications to the current training methodology for WP players to include strength and high-intensity training for athlete preparation in this sport.

Impairment of Performance Variables After In-Season Strength-Training Cessation in Elite Cyclists.

PubMed

Rønnestad, Bent R; Hansen, Joar; Hollan, Ivana; Spencer, Matt; Ellefsen, Stian

2016-09-01

The current study investigated the effects of 8 wk of strength-training cessation after 25 wk of strength training on strength- and cycling-performance characteristics. Elite cyclists were randomly assigned to either 25 wk of endurance training combined with heavy strength training (EXP, n = 7, maximal oxygen uptake [V̇O 2max ] 77 ± 6 mL . kg -1 . min -1 ; 3 × 4-10 RM, 1 to 2 d/wk) or to endurance training only (CON, n = 7, V̇O 2max 73 ± 5 mL . kg -1 . min -1 ). Thereafter, both groups performed endurance training only for 8 wk, coinciding with the initial part of the competition season. Data were assessed for practical significance using magnitude-based inferences. During the 25-wk preparatory period, EXP had a larger positive impact on maximal isometric half-squat force, squat jump (SJ), maximal aerobic power (W max ), power output at 4 mmol/L [La], and mean power in 30-s Wingate test than did CON (ES = 0.46-0.74). Conversely, during the 8-wk competition period EXP had a reduction in SJ, W max , and mean power in the 30-s Wingate test compared with CON (ES = 0.49-0.84). The present findings suggest rapid decline of adaptations on termination of strength training during the first 8 wk of the competition period in elite cyclists.

An approach to counteracting long-term microgravity-induced muscle atrophy

NASA Technical Reports Server (NTRS)

Tesch, P. A.; Buchanan, P.; Dudley, G. A.

1990-01-01

To find means of alleviating muscle atrophy induced by long-term microgravity, the effects of a 19-week-long heavy-resistance training regime (using either concentric muscle actions only or concentric and eccentric muscle actions) on the strengths of the exercised knee extensor muscle group were investigated in two groups of male human subjects performing two types of training exercises: supine leg press or/and seated knee extension. Results show that a training program in which both the concentric and the eccentric muscle action was performed led to substantially greater increases in maximal muscle strength than when only concentric exercises were performed.

Daily Overfeeding from Protein and/or Carbohydrate Supplementation for Eight Weeks in Conjunction with Resistance Training Does not Improve Body Composition and Muscle Strength or Increase Markers Indicative of Muscle Protein Synthesis and Myogenesis in Resistance-Trained Males

PubMed Central

Spillane, Mike; Willoughby, Darryn S.

2016-01-01

This study determined the effects of heavy resistance training and daily overfeeding with carbohydrate and/or protein on blood and skeletal muscle markers of protein synthesis (MPS), myogenesis, body composition, and muscle performance. Twenty one resistance-trained males were randomly assigned to either a protein + carbohydrate [HPC (n = 11)] or a carbohydrate [HC (n = 10)] supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after eight weeks of resistance training and supplementation. Data were analyzed by two-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were significantly increased in both groups in response to resistance training, but not supplementation (p < 0.05); however, lean mass was not significantly increased in either group (p = 0.068). Upper- (p = 0.024) and lower-body (p = 0.001) muscle strength and myosin heavy chain (MHC) 1 (p = 0.039) and MHC 2A (p = 0.027) were also significantly increased with resistance training. Serum IGF-1, GH, and HGF were not significantly affected (p > 0.05). Muscle total DNA, total protein, and c-Met were not significantly affected (p > 0.05). In conjunction with resistance training, the peri-exercise and daily overfeeding of protein and/or carbohydrate did not preferentially improve body composition, muscle performance, and markers indicative of MPS and myogenic activation. Key points In response to 56 days of heavy resistance training and HC or HPC supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups. The supplementation of HPC had no preferential effect on augmenting serum IGF-1 GH, or HGF. The supplementation of HPC had no preferential effect on augmenting increases in total muscle protein content or the myogenic markers, total DNA and muscle cMet content. In response to 56 days of a daily supplemental dose of 94 g of protein and 196 g of carbohydrate, the HPC group was no more effective than 312 g of carbohydrate in the HC group in increasing muscle strength and mass due to its ability to elevate serum anabolic hormones and growth factors and markers of myogenic activation of satellite cells. PMID:26957922

The effect of sprinting after each set of heavy resistance training on the running speed and jumping performance of young basketball players.

PubMed

Tsimahidis, Konstantinos; Galazoulas, Christos; Skoufas, Dimitrios; Papaiakovou, Georgios; Bassa, Eleni; Patikas, Dimitrios; Kotzamanidis, Christos

2010-08-01

The purpose of this study was to investigate the effect of a 10-week heavy resistance combined with a running training program on the strength, running speed (RS), and vertical jump performance of young basketball players. Twenty-six junior basketball players were equally divided in 2 groups. The control (CON) group performed only technical preparation and the group that followed the combined training program (CTP) performed additionally 5 sets of 8-5 repetition maximum (RM) half squat with 1 30-m sprint after each set. The evaluation took place before training and after the 5th and 10th weeks of training. Apart from the 1RM half squat test, the 10- and 30-m running time was measured using photocells and the jump height (squat, countermovement jump, and drop jump) was estimated taking into account the flight time. The 1RM increased by 30.3 +/- 1.5% at the 10th week of training for the CTP group (p < 0.05), whereas the CON group showed no significant increase (1.1 +/- 1.6%, p > 0.05). In general, all measured parameters showed a statistically significant increase after the 5th and 10th weeks (p < 0.05), in contrast to the CON group (p > 0.05). This suggests that the applied CTP is beneficial for the strength, RS, and jump height of young basketball players. The observed adaptations in the CTP group could be attributed to learning factors and to a more optimal transfer of the strength gain to running and jumping performance.

Effect of resistance training on muscle strength and rate of force development in healthy older adults: A systematic review and meta-analysis.

PubMed

Guizelini, Pedrode Camargo; de Aguiar, Rafael Alves; Denadai, Benedito Sérgio; Caputo, Fabrizio; Greco, Camila Coelho

2018-02-01

Rapid force capacity, identified by rate of rise in contractile force at the onset of contraction, i.e., the rate of force development (RFD), has been considered an important neuromuscular parameter of physical fitness in elderly individuals. Randomized control studies conducted in adults have found that resistance training may elicit different outcomes in terms of RFD and muscle strength. Thus, the main purpose of this study was to review systematically the literature for studies regarding the influence of resistance training on muscle strength and RFD in elderly persons. A literature search was performed in major electronic databases from inception to March 2017. Studies including health individuals with a mean age≥60years, describing the effect of resistance training on RFD and muscle strength were found eligible. The outcomes were calculated as the difference in percentage change between control and experimental groups (% change) and data were presented as mean±95% confidence limits. Meta-analyses were performed using a random-effects model and, in addition, simple and multiple meta-regression analyses were used to identify effects of age, training type, sessions per week and training duration on % change in RFD and muscle strength. Thirteen training effects were collected from 10 studies included in the meta-analysis. The resistance training program had a moderate beneficial effect on both muscle strength (% change=18.40%, 95% CL 13.69-23.30, p<0.001) and RFD (% change=26.68, 95% CL 14.41-35.52, p<0.001). Results of the meta-regression revealed that the variables age, training type (i.e., strength and explosive), training duration (4-16weeks) and sessions per week had no significant effects on muscle strength and RFD improvement. Moreover, there was no significant relationship (p=0.073) between the changes in muscle strength and RFD. It can be concluded that explosive training and heavy strength training are effective resistance training methods aiming to improve both muscle strength and RFD after short-to-medium training period. However, muscle strength and RFD seem to adapt differently to resistance training programs, suggesting caution for their interchangeable use in clinical assessments of the elderly. Copyright © 2017 Elsevier Inc. All rights reserved.

The Effect of Two Different Concurrent Training Programs on Strength and Power Gains in Highly-Trained Individuals

PubMed Central

Petré, Henrik; Löfving, Pontus; Psilander, Niklas

2018-01-01

The effects of concurrent strength and endurance training have been well studied in untrained and moderately-trained individuals. However, studies examining these effects in individuals with a long history of resistance training (RT) are lacking. Additionally, few studies have examined how strength and power are affected when different types of endurance training are added to an RT protocol. The purpose of the present study was to compare the effects of concurrent training incorporating either low-volume, high-intensity interval training (HIIT, 8-24 Tabata intervals at ~150% of VO2max) or high-volume, medium-intensity continuous endurance training (CT, 40-80 min at 70% of VO2max), on the strength and power of highly-trained individuals. Sixteen highly-trained ice-hockey and rugby players were divided into two groups that underwent either CT (n = 8) or HIIT (n = 8) in parallel with RT (2-6 sets of heavy parallel squats, > 80% of 1RM) during a 6-week period (3 sessions/wk). Parallel squat performance improved after both RT + CT and RT + HIIT (12 ± 8% and 14 ± 10% respectively, p < 0.01), with no difference between the groups. However, aerobic power (VO2max) only improved after RT + HIIT (4 ± 3%, p < 0.01). We conclude that strength gains can be obtained after both RT + CT and RT + HIIT in athletes with a prior history of RT. This indicates that the volume and/or intensity of the endurance training does not influence the magnitude of strength improvements during short periods of concurrent training, at least for highly-trained individuals when the endurance training is performed after RT. However, since VO2max improved only after RT + HIIT and this is a time efficient protocol, we recommend this type of concurrent endurance training. Key points Lower body maximal strength is improved after concurrent strength and endurance training in highly trained individuals. The magnitude of this strength improvement is not influenced by the type of endurance training, i.e. HIIT or CT. HIIT improves VO2max and is more time efficient than CT. HIIT is recommended to athletes when concurrently training for strength and endurance. PMID:29769816

Heavy resistance training and peri-exercise ingestion of a multi-ingredient ergogenic nutritional supplement in males: effects on body composition, muscle performance and markers of muscle protein synthesis.

PubMed

Spillane, Mike; Schwarz, Neil; Willoughby, Darryn S

2014-12-01

This study determined the effects of heavy resistance training and peri-exercise ergogenic multi-ingredient nutritional supplement ingestion on blood and skeletal markers of muscle protein synthesis (MPS), body composition, and muscle performance. Twenty-four college-age males were randomly assigned to either a multi-ingredient SizeOn Maximum Performance (SIZE) or protein/carbohydrate/creatine (PCC) comparator supplement group in a double-blind fashion. Body composition and muscle performance were assessed, and venous blood samples and muscle biopsies were obtained before and after 6 weeks of resistance training and supplementation. Data were analyzed by 2-way ANOVA (p ≤ 0.05). Total body mass, body water, and fat mass were not differentially affected (p > 0.05). However, fat-free mass was significantly increased in both groups in response to resistance training (p = 0.037). Lower-body muscle strength (p = 0.029) and endurance (p = 0.027) were significantly increased with resistance training, but not supplementation (p > 0.05). Serum insulin, IGF-1, GH, and cortisol were not differentially affected (p > 0.05). Muscle creatine content was significantly increased in both groups from supplementation (p = 0.044). Total muscle protein (p = 0.038), MHC 1 (p = 0.041), MHC 2A, (p = 0.029), total IRS- (p = 0.041), and total Akt (p = 0.011) were increased from resistance training, but not supplementation. In response to heavy resistance training when compared to PCC, the peri-exercise ingestion of SIZE did not preferentially improve body composition, muscle performance, and markers indicative of MPS. Key pointsIn response to 42 days of heavy resistance training and either SizeOn Maximum Performance or protein/carbohydrate/creatine supplementation, similar increases in muscle mass and strength in both groups occurred; however, the increases were not different between supplement groups.The supplementation of SizeOn Maximum Performance had no preferential effect on augmenting serum insulin, IGF-1, and GH, or in decreasing cortisol.While resistance training was effective in increasing total creatine content in skeletal muscle, myofibrillar protein, and the content of total IRS-1 and Akt, it was not preferentially due to SizeOn Maximum Performance supplementation.At the daily dose of 50 g, SizeOn Maximum Performance supplementation for 42 days combined with resistance training does not increases muscle mass and strength due to its ability to elevate serum hormones and growth factors or in its ability to augment skeletal muscle signaling pathway markers indicative of muscle protein synthesis when compared to an equivalent daily dose of protein/carbohydrate/creatine.

Irisin and FNDC5: effects of 12-week strength training, and relations to muscle phenotype and body mass composition in untrained women.

PubMed

Ellefsen, S; Vikmoen, O; Slettaløkken, G; Whist, J E; Nygaard, H; Hollan, I; Rauk, I; Vegge, G; Strand, T A; Raastad, T; Rønnestad, B R

2014-09-01

To investigate the effects of strength training on abundances of irisin-related biomarkers in skeletal muscle and blood of untrained young women, and their associations with body mass composition, muscle phenotype and levels of thyroid hormones. Eighteen untrained women performed 12 weeks of progressive whole-body heavy strength training, with measurement of strength, body composition, expression of irisin-related genes (FNDC5 and PGC1α) in two different skeletal muscles, and levels of serum-irisin and -thyroid hormones, before and after the training intervention. The strength training intervention did not result in changes in serum-irisin or muscle FNDC5 expression, despite considerable effects on strength, lean body mass (LBM) and skeletal muscle phenotype. Our data indicate that training affects irisin biology in a LBM-dependent manner. However, no association was found between steady-state serum-irisin or training-associated changes in serum-irisin and alterations in body composition. FNDC5 expression was higher in m.Biceps brachii than in m.Vastus lateralis, with individual expression levels being closely correlated, suggesting a systemic mode of transcriptional regulation. In pre-biopsies, FNDC5 expression was correlated with proportions of aerobic muscle fibers, a relationship that disappeared in post-biopsies. No association was found between serum-thyroid hormones and FNDC5 expression or serum-irisin. No evidence was found for an effect of strength training on irisin biology in untrained women, though indications were found for a complex interrelationship between irisin, body mass composition and muscle phenotype. FNDC5 expression was closely associated with muscle fiber composition in untrained muscle.

The Effect of Two Different Concurrent Training Programs on Strength and Power Gains in Highly-Trained Individuals.

PubMed

Petré, Henrik; Löfving, Pontus; Psilander, Niklas

2018-06-01

The effects of concurrent strength and endurance training have been well studied in untrained and moderately-trained individuals. However, studies examining these effects in individuals with a long history of resistance training (RT) are lacking. Additionally, few studies have examined how strength and power are affected when different types of endurance training are added to an RT protocol. The purpose of the present study was to compare the effects of concurrent training incorporating either low-volume, high-intensity interval training (HIIT, 8-24 Tabata intervals at ~150% of VO 2max ) or high-volume, medium-intensity continuous endurance training (CT, 40-80 min at 70% of VO 2max ), on the strength and power of highly-trained individuals. Sixteen highly-trained ice-hockey and rugby players were divided into two groups that underwent either CT (n = 8) or HIIT (n = 8) in parallel with RT (2-6 sets of heavy parallel squats, > 80% of 1RM) during a 6-week period (3 sessions/wk). Parallel squat performance improved after both RT + CT and RT + HIIT (12 ± 8% and 14 ± 10% respectively, p < 0.01), with no difference between the groups. However, aerobic power (VO 2max ) only improved after RT + HIIT (4 ± 3%, p < 0.01). We conclude that strength gains can be obtained after both RT + CT and RT + HIIT in athletes with a prior history of RT. This indicates that the volume and/or intensity of the endurance training does not influence the magnitude of strength improvements during short periods of concurrent training, at least for highly-trained individuals when the endurance training is performed after RT. However, since VO 2max improved only after RT + HIIT and this is a time efficient protocol, we recommend this type of concurrent endurance training.

The role of strength and power during performance of high intensity military tasks under heavy load carriage.

PubMed

Mala, Jesse; Szivak, Tunde K; Flanagan, Shawn D; Comstock, Brett A; Laferrier, Justin Z; Maresh, Carl M; Kraemer, William J

2015-01-01

Previous research has investigated the physiological determinants of heavy load carriage while performing medium to long distance road marching, yet research examining the physiological underpinnings of high-intensity battlefield tasks is limited. This study sought to examine the role of strength and power during high-intensity combat tasks under heavy load carriage. Eighteen recreationally trained men (mean±SD: age, 21±2 years; height, 172±6 cm; weight, 80±13 kg) participated in this study and performed an anaerobic combat course under 2 randomized experimental conditions; unloaded and loaded. Subjects performed 3 trials under each condition on separate days, with a 5-minute rest between each trial. In the unloaded trial, subjects wore a uniform with boots weighing approximately 3.2 kg. During the loaded trial, in addition to the uniform and boots, subjects wore Interceptor body armor (6.94 kg-9.10 kg) and a MOLLE rucksack weighing 30 kg. The course consisted of 3 consecutive tasks, which began from the prone position, led into a 30 m sprint, followed by a 27 m zigzag run, and ended with a 10 m casualty drag weighing approximately 79.4 kg. Pearson correlations showed significant (P≤.05) strong correlations between lower body strength (r=-0.63, -0.62), lower body power (r=-0.67, -0.67) and upper body strength (r=-0.60, -0.62) and overall performance times in the unloaded and loaded condition, respectively. Strength and power are strongly related to high-intensity military tasks with and without heavy load carriage.

D-aspartic acid supplementation combined with 28 days of heavy resistance training has no effect on body composition, muscle strength, and serum hormones associated with the hypothalamo-pituitary-gonadal axis in resistance-trained men.

PubMed

Willoughby, Darryn S; Leutholtz, Brian

2013-10-01

It was hypothesized that D-aspartic acid (D-ASP) supplementation would not increase endogenous testosterone levels or improve muscular performance associated with resistance training. Therefore, body composition, muscle strength, and serum hormone levels associated with the hypothalamo-pituitary-gonadal axis were studied after 28 days of resistance training and D-ASP supplementation. Resistance-trained men resistance trained 4 times/wk for 28 days while orally ingesting either 3 g of placebo or 3 g of D-ASP. Data were analyzed with 2 × 2 analysis of variance (P < .05). Before and after resistance training and supplementation, body composition and muscle strength, serum gonadal hormones, and serum D-ASP and d-aspartate oxidase (DDO) were determined. Body composition and muscle strength were significantly increased in both groups in response to resistance training (P < .05) but not different from one another (P > .05). Total and free testosterone, luteinizing hormone, gonadotropin-releasing hormone, and estradiol were unchanged with resistance training and D-ASP supplementation (P > .05). For serum D-ASP and DDO, D-ASP resulted in a slight increase compared with baseline levels (P > .05). For the D-ASP group, the levels of serum DDO were significantly increased compared with placebo (P < .05). The gonadal hormones were unaffected by 28 days of D-ASP supplementation and not associated with the observed increases in muscle strength and mass. Therefore, at the dose provided, D-ASP supplementation is ineffective in up-regulating the activity of the hypothalamo-pituitary-gonadal axis and has no anabolic or ergogenic effects in skeletal muscle. © 2013 Elsevier Inc. All rights reserved.

Resistance training performed at distinct angular velocities elicits velocity-specific alterations in muscle strength and mobility status in older adults.

PubMed

Englund, Davis A; Sharp, Rick L; Selsby, Joshua T; Ganesan, Shanthi S; Franke, Warren D

2017-05-01

The purpose of this study was to compare the effects of high and low velocity knee extension training on changes in muscle strength and mobility status in high-functioning older adults. Twenty-six (16 female, 10 male) older adults (mean age of 65) were randomized to either 6weeks of low velocity resistance training (LVRT) performed at 75°/s or high velocity resistance training (HVRT) performed at 240°/s. Both groups performed 3 sets of knee extension exercises at maximal effort, 3 times a week. Muscle strength was assessed through a range of testing velocities on an isokinetic dynamometer. Mobility status was assessed with the short physical performance battery (SPPB) and myosin heavy chain (MyHC) transcript levels were quantified via qRT-PCR. From baseline to post-training, there were several significant (P<0.05) differences in muscle strength and functional characteristics in LVRT (n=13) and HVRT (n=13) groups. From baseline to post-training, MyHC-α mRNA and MyHC-IIa mRNA showed a significant (P<0.05) increase within HVRT but MyHC-IIx mRNA did not change significantly. Our results demonstrate HVRT provides a greater number of muscular enhancements when compared to LVRT, particularly under conditions of high velocity muscle contraction. HVRT is emerging as the optimal training stimulus for the older adult. The present study demonstrates, in addition to increased strength and functional outcomes, HVRT elicits a potentially therapeutic (i.e., slow to fast) transcriptional response in MyHC. Copyright © 2017 Elsevier Inc. All rights reserved.

Is the chronic painful tendinosis tendon a strong tendon?: a case study involving an Olympic weightlifter with chronic painful Jumper's knee.

PubMed

Gisslén, Karl; Ohberg, Lars; Alfredson, Håkan

2006-09-01

The chronic painful tendinosis tendon is generally considered a degenerated and weak tendon. However, this has not been scientifically verified, and is to be considered a hypothesis. We present here a case study involving a high-level Olympic weightlifter with chronic painful patellar tendinosis who started heavy-weight training very early after successful treatment with sclerosing injections. A 25-year-old super heavy-weight (+105 kg) Olympic weightlifter with 9 months duration of severe pain (prohibiting full training) in the proximal patellar tendon, where ultrasound and Doppler showed a widened tendon with structural changes and neovascularisation, was given one treatment with ultrasound and Doppler-guided injections of the sclerosing agent polidocanol. The injections targeted the neovessels posterior to the tendon. The patient was pain-free after the treatment, and already after 2-weeks he started with heavy-weight training (240 kg in deep squats) to try to qualify for the Olympics. Additional very heavy training on training camps, most often without having any discomfort or pain in the patellar tendon, resulted in Swedish records and ninth place at the European Championships 17 weeks after the treatment. Despite beating the national records, he did not qualify for the Olympics. Ultrasound and Doppler follow-ups have shown only a few remaining neovessels, and little structural tendon changes. This case questions previous theories about the weak tendinosis tendon, and stresses the importance of studies evaluating tendon strength.

A Scientific Approach to Improve Physiological Capacity of an Elite Cyclist.

PubMed

Rønnestad, Bent R; Hansen, Joar

2018-03-01

Previous studies in endurance athletes have indicated that block periodization (BP) can be a good alternative to the more traditional organization of training despite the fact that the total volume and intensity of the training are similar. However, these studies usually last only 4-12 wk. The aim of the present single-case study was to investigate the consequences of 58 wk with systematic BP of low-intensity training (LIT), moderate-intensity training (MIT), and high-intensity interval training (HIT) including incorporation of heavy strength training. It is important that a maintenance stimulus on the nonprioritized training modalities was added in the different training blocks. Performance-related variables were tested regularly during the intervention. The studied cyclist started with a maximal oxygen uptake (VO 2 max) of 73.8 mL · kg -1  · min -1 , peak aerobic power (W max ) of 6.14 W/kg, and a power output at 3 mmol/L blood lactate concentration (Power 3la -) of 3.6 W/kg. Total training volume during the 58-wk intervention was 678 h, of which 452 h were LIT (67%), 124 h were MIT (18%), 69 h were HIT (10%), and 34 h were heavy strength training (5%). The weekly training volume had a large range depending on the focus of the training block. After the intervention the cyclist's VO 2 max was 87 mL · kg -1  · min -1 , W max was 7.35 W/kg, and Power 3la - was 4.9 W/kg. This single case indicates that the present training program can be a good alternative to the more traditional organization of long-term training of endurance athletes. However, a general recommendation cannot be given based on this single-case study.

The effects of low-repetition and light-load power training on bone mineral density in postmenopausal women with sarcopenia: a pilot study.

PubMed

Hamaguchi, Kanako; Kurihara, Toshiyuki; Fujimoto, Masahiro; Iemitsu, Motoyuki; Sato, Koji; Hamaoka, Takafumi; Sanada, Kiyoshi

2017-05-02

Age-related reduction in bone mineral density (BMD) is generally accelerated in women after menopause, and could be even more pronounced in individuals with sarcopenia. Light-load power training with a low number of repetitions would increase BMD, significantly reducing bone loss in individuals at risk of osteoporosis. This study investigated the effects of low-repetition, light-load power training on BMD in Japanese postmenopausal women with sarcopenia. The training group (n = 7) followed a progressive power training protocol that increased the load with a weighted vest, for two sessions per week, over the course of 6 weeks. The training exercise comprised five kinds of exercises (squats, front lunges, side lunges, calf raises, and toe raises), and each exercise contained eight sets of three repetitions with a 15-s rest between each set. The control group (n = 8) did not undergo any training intervention. We measured BMD, muscle strength, and anthropometric data. Within-group changes in pelvis BMD and knee extensor strength were significantly greater in the training group than the control group (p = 0.029 and 0.030 for pelvis BMD and knee extensor strength, respectively). After low-repetition, light-load power training, we noted improvements in pelvis BMD (1.6%) and knee extensor strength (15.5%). No significant within- or between-group differences were observed for anthropometric data or forearm BMD. Six weeks of low-repetition, light-load power training improved pelvis BMD and knee extensor strength in postmenopausal women with sarcopenia. Since this training program does not require high-load exercise and is therefore easily implementable as daily exercise, it could be an effective form of exercise for sedentary adults at risk for osteoporosis who are fearful of heavy loads and/or training that could cause fatigue. This trial was registered with the University Hospital Medical Information Network on 31 October 2016 ( UMIN000024651 ).

Anaerobic power and physical function in strength-trained and non-strength-trained older adults.

PubMed

Slade, Jill M; Miszko, Tanya A; Laity, Jennifer H; Agrawal, Subodoh K; Cress, M Elaine

2002-03-01

Challenging daily tasks, such as transferring heavy items or rising from the floor, may be dependent on the ability to generate short bursts of energy anaerobically. The purposes of this study were to determine if strength-trained (ST) older adults have higher anaerobic power output compared with non-strength-trained (NST) older adults and to determine the relationship between anaerobic power and performance-based physical function. Thirty-five men and women (age 71.5 +/- 6.4 years, mean +/- SD; NST: n = 18, ST: n = 17) were grouped by training status. Outcome variables included relative anaerobic power (Wingate test), physical function measured with the Continuous Scale Physical Functional Performance Test (CS-PFP, scaled 0 to 100), and anthropometric lean thigh volume (LTV). Analysis of covariance (with age and sex as covariates) was used to determine group differences in the dependent variables listed above. Pearson's r was used to determine the relationship between anaerobic power, CS-PFP total score (TOT), and CS-PFP lower body strength domain score (LBS). The ST group had significantly higher mean anaerobic power (NST 58.9 +/- 16 W/l, ST 96.3 +/- 23 W/l), CS-PFP total (NST 61.2 +/- 13, ST 73.7 +/- 8), and LBS (NST 54.1 +/- 17, ST 70.9 +/- 8) compared with the NST group (p <.05). However, LTV was similar for both groups (NST 3.323 +/- 0.75; ST 3.179 +/- 0.79), which suggests that the ST group had higher muscle quality compared with the NST group. Anaerobic power was significantly related to TOT (r =.611, p =.001) and LBS (r =.650, p =.001). High levels of physical function in ST older adults may in part be explained by higher levels of anaerobic power associated with strength training.

Effect of strength training on orthostatic hypotension in older adults.

PubMed

Brilla, L R; Stephens, A B; Knutzen, K M; Caine, D

1998-01-01

This preliminary study attempted to identify the frequency of orthostatic hypotension (OH) in community dwelling older adults who volunteered to participate in an 8-week, heavy-resistance, strength-training program. It also assessed the effect of the strength-training program on OH. From a larger study (n = 53) on high-resistance strength training in older adults (mean age 71.4 +/- 6.6 years), a subset of subjects (n = 24), mean age 71.0 +/- 5.8 years, was evaluated who met at least one criterion for OH. All subjects were tested for resting blood pressures (BP) and heart rates (HR) in the supine, sitting, and standing positions. Also noted was their response to orthostatism in rising from a cot after 10 minutes and rising from a chair after 5 minutes. The subset was not different from the overall group in gender ratio, age, or effect of medication on BP. The treatment was an 8-week strength-training program at 80% of their one repetition maximum. Significant changes (P < 0.05) were shown in supine diastolic BP (+3.2 mm Hg), sitting systolic BP (-3.9), and standing HR (+4.9 beats per minute). In response to the orthostatic challenge, significant (P < 0.05) improvements were shown in systolic BP (+9.7 mm Hg), diastolic BP (+4.7), and HR (+3.2 beats per minute) for the rise from chair, and in diastolic BP (+6.7 mm Hg) rise from the cot. These data show that OH is not uncommon (45%) in community dwelling older adults. A strength training program in older adults has little effect on resting BP, but elicits a positive adaptation to an orthostatic challenge.

Effects of Heavy-Resistance Strength and Balance Training on Unilateral and Bilateral Leg Strength Performance in Old Adults

PubMed Central

Beurskens, Rainer; Gollhofer, Albert; Muehlbauer, Thomas; Cardinale, Marco; Granacher, Urs

2015-01-01

The term “bilateral deficit” (BLD) has been used to describe a reduction in performance during bilateral contractions when compared to the sum of identical unilateral contractions. In old age, maximal isometric force production (MIF) decreases and BLD increases indicating the need for training interventions to mitigate this impact in seniors. In a cross-sectional approach, we examined age-related differences in MIF and BLD in young (age: 20–30 years) and old adults (age: >65 years). In addition, a randomized-controlled trial was conducted to investigate training-specific effects of resistance vs. balance training on MIF and BLD of the leg extensors in old adults. Subjects were randomly assigned to resistance training (n = 19), balance training (n = 14), or a control group (n = 20). Bilateral heavy-resistance training for the lower extremities was performed for 13 weeks (3 × / week) at 80% of the one repetition maximum. Balance training was conducted using predominately unilateral exercises on wobble boards, soft mats, and uneven surfaces for the same duration. Pre- and post-tests included uni- and bilateral measurements of maximal isometric leg extension force. At baseline, young subjects outperformed older adults in uni- and bilateral MIF (all p < .001; d = 2.61–3.37) and in measures of BLD (p < .001; d = 2.04). We also found significant increases in uni- and bilateral MIF after resistance training (all p < .001, d = 1.8-5.7) and balance training (all p < .05, d = 1.3-3.2). In addition, BLD decreased following resistance (p < .001, d = 3.4) and balance training (p < .001, d = 2.6). It can be concluded that both training regimens resulted in increased MIF and decreased BLD of the leg extensors (HRT-group more than BAL-group), almost reaching the levels of young adults. PMID:25695770

Short-term Periodization Models: Effects on Strength and Speed-strength Performance.

PubMed

Hartmann, Hagen; Wirth, Klaus; Keiner, Michael; Mickel, Christoph; Sander, Andre; Szilvas, Elena

2015-10-01

Dividing training objectives into consecutive phases to gain morphological adaptations (hypertrophy phase) and neural adaptations (strength and power phases) is called strength-power periodization (SPP). These phases differ in program variables (volume, intensity, and exercise choice or type) and use stepwise intensity progression and concomitant decreasing volume, converging to peak intensity (peaking phase). Undulating periodization strategies rotate these program variables in a bi-weekly, weekly, or daily fashion. The following review addresses the effects of different short-term periodization models on strength and speed-strength both with subjects of different performance levels and with competitive athletes from different sports who use a particular periodization model during off-season, pre-season, and in-season conditioning. In most periodization studies, it is obvious that the strength endurance sessions are characterized by repetition zones (12-15 repetitions) that induce muscle hypertrophy in persons with a low performance level. Strictly speaking, when examining subjects with a low training level, many periodization studies include mainly hypertrophy sessions interspersed with heavy strength/power sessions. Studies have demonstrated equal or statistically significant higher gains in maximal strength for daily undulating periodization compared with SPP in subjects with a low to moderate performance level. The relatively short intervention period and the lack of concomitant sports conditioning call into question the practical value of these findings for competitive athletes. Possibly owing to differences in mesocycle length, conditioning programs, and program variables, competitive athletes either maintained or improved strength and/or speed-strength performance by integrating daily undulating periodization and SPP during off-season, pre-season and in-season conditioning. In high-performance sports, high-repetition strength training (>15) should be avoided because it does not provide an adequate training stimulus for gains in muscle cross-sectional area and strength performance. High-volume circuit strength training performed over 2 years negatively affected the development of the power output and maximal strength of the upper extremities in professional rugby players. Indeed, meta-analyses and results with weightlifters, American Football players, and throwers confirm the necessity of the habitual use of ≥80% 1 RM: (1) to improve maximal strength during the off-season and in-season in American Football, (2) to reach peak performance in maximal strength and vertical jump power during tapering in track-and-field, and (3) to produce hypertrophy and strength improvements in advanced athletes. The integration and extent of hypertrophy strength training in in-season conditioning depend on the duration of the contest period, the frequency of the contests, and the proportion of the conditioning program. Based on the literature, 72 h between hypertrophy strength training and strength-power training should be provided to allow for adequate regeneration times and therefore maximal stimulus intensities in training. This conclusion is only valid if the muscle is not trained otherwise during this regeneration phase. Thus, rotating hypertrophy and strength-power sessions in a microcycle during the season is a viable option. Comparative studies in competitive athletes who integrated strength training during pre-season conditioning confirm a tendency for gains in explosive strength and statistically significant improvements in medicine ball throw through SPP but not through daily undulating periodization. These findings indicate that to maximize the speed-strength in the short term (peaking), elite athletes should perform strength-power training twice per week. It is possible to perform a single strength-power session with the method of maximum explosive strength actions moving high-weight loads (90% 1 repetition maximum [RM]) at least 1-2 days before competition because of the shorter regeneration times and potentiation effects. Compared with ballistic strength training (30% 1 RM), this method has been shown to provide statistically superior gains in maximal strength, peak power, impulse size, and explosive strength during tapering in track-and-field throwers. The speed-strength performance in drop jumps of strength-trained subjects showed potentiation effects 48-148 h after a single strength-power training session. Regarding neuromuscular performance, plyometric exercises can even be performed after strength-power training on the same day if a minimum rest period of 3 h is provided.

[Neuromuscular system and aging: involutions and implications].

PubMed

Paillard, Thierry

2013-12-01

In aged human, the number of muscle fibers and motor units decreases. The remaining motor units lose their functionality (decrease of the discharge frequency, greater fluctuation of the discharge) particularly those which contain type II fibers. The renewal of intracellular proteins declines which creates a negative balance between the daily protein losses and the capacities to renew them. The activity of the protein kinase (Akt) that stimulates the synthesis of regulation proteins (mTOR, p70S6, IGFBP-5) declines whereas the factors of degradation of proteins (NF-kappa B) are activated. Besides, the process of activation and proliferation of satellite cells is affected and the production of anabolic hormones and local factors is decreased. After a strength training program, muscle hypertrophy is linked to the protein synthesis at the level of myosin heavy chain (MHC) isoforms in older subjects. However, the transcription of the genes that code the MHC-I (slow form) increases and the transcription of the genes that code the MHC-II (fast form) decreases. Thus, the transition of the phenotype towards a slower form cannot be inverted by strength training during the advanced in age. Moreover, strength training enables to decrease the proportion of fibers containing MHC of hybrid form in the process of evolution. Hence, strength training can engender a stabilization of the muscular phenotype i.e. different isoforms of MHC. In addition, strength training counteracts the noxious effects mentioned above by generating muscular hypertrophy thanks to a reactive increase in the production of anabolic hormones. A program of aerobic training can induce an increase in the synthesis of ARN messengers coding isoforms related to the oxidative metabolism (MHC-I and to a lesser extent MHC-IIa) while the transcribed for the type MHC-IIx decrease.

Strengthening the Gluteus Medius Using Various Bodyweight and Resistance Exercises

PubMed Central

Tufano, James J.; Golas, Artur; Petr, Miroslav

2016-01-01

ABSTRACT THE GLUTEUS MEDIUS (Gmed) IS AN IMPORTANT MUSCLE AND, IF WEAK, CAN CAUSE KNEE, HIP, OR LOWER-BACK PATHOLOGIES. THIS ARTICLE REVIEWS METHODS OF Gmed STRENGTH ASSESSMENT, PROVIDES EXERCISES THAT TARGET THE Gmed BASED ON ELECTROMYOGRAPHY, PRESENTS HOW TO IMPLEMENT Gmed STRENGTHENING IN HEAVY RESISTANCE TRAINING PROGRAMS, AND EXPLAINS THE IMPORTANCE OF INCLUDING THESE EXERCISES IN THESE PROGRAMS. PMID:27340373

Neuromuscular Adaptations to Reduced Use

NASA Technical Reports Server (NTRS)

Ploutz-Snyder, Lori

2009-01-01

This viewgraph presentation reviews the studies done to reduce neuromuscular strength loss during unilateral lower limb suspension (ULLS). Since there are animals that undergo fairly long periods of muscular disuse without any or minimal muscular atrophy, there is an answer to that might be applicable to human in situations that require no muscular use to diminish the effects of muscular atrophy. Three sets of ULLS studies were reviewed indicated that muscle strength decreased more than the muscle mass. The study reviewed exercise countermeasures to combat the atrophy, including: ischemia maintained during Compound muscle action potential (CMAP), ischemia and low load exercise, Japanese kaatsu, and the potential for rehabilitation or situations where heavy loading is undesirable. Two forms of countermeasures to unloading have been successful, (1) high-load resistance training has maintained muscle mass and strength, and low load resistance training with blood flow restriction (LL(sub BFR)). The LL(sub BFR) has been shown to increase muscle mass and strength. There has been significant interest in Tourniquet training. An increase in Growth Hormone(GH) has been noted for LL(sub BFR) exercise. An experimental study with 16 subjects 8 of whom performed ULLS, and 8 of whom performed ULLS and LL(sub BFR) exercise three times per week during the ULLS. Charts show the results of the two groups, showing that performing LL(sub BFR) exercise during 30 days of ULLS can maintain muscle size and strength and even improve muscular endurance.

Potentiation: Effect of Ballistic and Heavy Exercise on Vertical Jump Performance.

PubMed

Hester, Garrett M; Pope, Zachary K; Sellers, John H; Thiele, Ryan M; DeFreitas, Jason M

2017-03-01

Hester, GM, Pope, ZK, Sellers, JH, Thiele, RM, and DeFreitas, JM. Potentiation: Effect of ballistic and heavy exercise on vertical jump performance. J Strength Cond Res 31(3): 660-666, 2017-The purpose of this study was to compare the acute effects of heavy and ballistic conditioning protocols on vertical jump performance in resistance-trained men. Fourteen resistance-trained men (mean ± SD: age = 22 ± 2.1 years, body mass = 86.29 ± 9.95 kg, and height = 175.39 ± 9.34 cm) with an average relative full squat of 2.02 ± 0.28 times their body mass participated in this study. In randomized, counterbalanced order, subjects performed two countermovement vertical jumps before and 1, 3, 5, and 10 minutes after either performing 10 rapid jump squats or 5 heavy back squats. The back squat protocol consisted of 5 repetitions at 80% one repetition maximum (1RM), whereas the jump squat protocol consisted of 10 repetitions at 20% 1RM. Peak jump height (in centimeters) using a jump mat, along with power output (in Watts) and velocity (in meters per second) through a linear transducer, was recorded for each time interval. There was no significant condition × time interaction for any of the dependent variables (p = 0.066-0.127). In addition, there was no main effect for condition for any of the dependent variables (p = 0.457-0.899). Neither the ballistic nor heavy protocol used in this study enhanced vertical jump performance at any recovery interval. The use of these protocols in resistance-trained men to produce postactivation potentiation is not recommended.

Operational Physical Performance and Fitness in Military Women: Physiological, Musculoskeletal Injury, and Optimized Physical Training Considerations for Successfully Integrating Women Into Combat-Centric Military Occupations.

PubMed

Nindl, Bradley C; Jones, Bruce H; Van Arsdale, Stephanie J; Kelly, Karen; Kraemer, William J

2016-01-01

This article summarizes presentations from a 2014 United States Department of Defense (DoD) Health Affairs Women in Combat symposium addressing physiological, musculoskeletal injury, and optimized physical training considerations from the operational physical performance section. The symposium was held to provide a state-of-the-science meeting on the U.S. DoD's rescinding of the ground combat exclusion policy opening up combat-centric occupations to women. Physiological, metabolic, body composition, bone density, cardiorespiratory fitness, and thermoregulation differences between men and women were briefly reviewed. Injury epidemiological data are presented within military training and operational environments demonstrating women to be at a higher risk for musculoskeletal injuries than men. Physical training considerations for improved muscle strength and power, occupational task performance, load carriage were also reviewed. Particular focus of this article was given to translating physiological and epidemiological findings from the literature on these topics toward actionable guidance and policy recommendations for military leaders responsible for military physical training doctrine: (1) inclusion of resistance training with special emphasis on strength and power development (i.e., activation of high-threshold motor units and recruitment of type II high-force muscle fibers), upper-body strength development, and heavy load carriage, (2) moving away from "field expediency" as the major criteria for determining military physical training policy and training implementation, (3) improvement of load carriage ability with emphasis placed on specific load carriage task performance, combined with both resistance and endurance training, and (4) providing greater equipment resources, coaching assets, and increased training time dedicated to physical readiness training. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Effects of 8 weeks of vibration training at different frequencies (1 or 15 Hz) in senior sportsmen on torque and force development and of 1 year of training on muscle fibers.

PubMed

Kern, H; Kovarik, J; Franz, C; Vogelauer, M; Löfler, S; Sarabon, N; Grim-Stieger, M; Biral, D; Adami, N; Carraro, U; Zampieri, S; Hofer, Ch

2010-02-01

To examine the effects of 8 weeks of vibration training at different frequencies (1 and 15 Hz) on maximal isometric torque and force development in senior sportsmen, and of 1 year of heavy-resistance and vibration trainings on muscle fibers. Seven healthy senior sportsmen (mean age: 69.0 +/- 5.4 years) performed an 8 weeks of strength training of knee extensors. Vibrations were applied vertically to the axis of movement during training. One leg of each subject was trained at a frequency of 1 Hz, while the other leg was trained at 15 Hz. Measures of isometric peak torque (at knee-angles of 60, 90 and 120 degrees ) and force development were recorded before and after training. Four sportsmen continued a year-long heavy-resistance training adding every second week a session of vibration training. After training, muscle biopsies were harvested from their quadriceps muscles and used for structural analyses. Morphometry of muscle fibers was performed by light microscopy. Immunohistochemistry using anti-MHCemb and anti-N-CAM antibodies was performed to measure potential muscle damage. Data from muscle morphometry were compared to that of a series of vastus lateralis biopsies harvested from 12 young sportsmen and four healthy elderly. Our results showed a significant increase in isometric peak torque at both 1 and 15 Hz vibration frequency in all three measured angles of the knee. There was no significant difference between the two frequencies, but we could find a higher increase in percentage of maximum power after the 1 Hz training. The results of force development showed a slight increase at the 1 Hz training in measured time frames from 0 to 50 and 200 ms, without statistical significance. A trend to significance was found at the 1 Hz training at the time window up to 200 ms. The 15 Hz training showed no significant changes of force development. Muscle biopsies show that the muscles of these well trained senior sportsmen contain muscle fibers which are 35% larger than those of sedentary elderly and, unexpectedly, 10% larger than those of young sportsmen. Despite 1 year of heavy resistance and vibration training, no evidence of muscle damage or denervation/reinnervation could be observed by light microscopy analyses, ATPase histochemistry and immunohistochemistry using anti-N-CAM or anti-MHC-emb antibodies. Integration of vibration to conventional strength training in elderly sportsmen induces similar improvement of isometric peak torque and force development independently from the vibration frequency after 8 weeks of training, and long-term results in the surprising evidence of hypertrophic muscle fibers larger than those of young active sportsmen. The observation that the vibration training with low frequency is safe opens the possibility to test these rehabilitation procedures in sedentary elderly.

Bone mineral density in elite junior Olympic weightlifters.

PubMed

Conroy, B P; Kraemer, W J; Maresh, C M; Fleck, S J; Stone, M H; Fry, A C; Miller, P D; Dalsky, G P

1993-10-01

The purpose of this study was to examine the relationship of bone mineral density (BMD) to muscular strength in highly trained young male athletes in order to gain insights concerning the influence of heavy resistance training on BMD. Twenty-five elite junior weightlifters (age, 17.4 +/- 1.4 yr) and 11 age-matched controls (16.9 +/- 1.1 yr) volunteered for this investigation. Measurements of BMD (g.cm-2) utilizing dual energy x-ray absorptiometry were obtained for the lumbar spine (L2-4) and the proximal femur (neck; trochanter, Ward's triangle). The BMD values for the junior lifters were found to be significantly greater at all sites for the junior weightlifters compared with their age-matched control group. The BMD values of the spine and femoral neck of the junior weightlifters when compared with adult reference data (i.e., 20-39 yr old men) were found to be significantly greater. Both simple and multiple regression analyses demonstrated significant relationships of BMD with strength accounting for 30-65% of the variance. These data suggest that in elite junior weightlifters, muscle strength, highly specific to the sport of weightlifting, has a major influence on BMD due to the influence of the chronic overloads experienced in training.

Physical activity as intervention for age-related loss of muscle mass and function: protocol for a randomised controlled trial (the LISA study)

PubMed Central

Eriksen, Christian Skou; Garde, Ellen; Reislev, Nina Linde; Wimmelmann, Cathrine Lawaetz; Bieler, Theresa; Ziegler, Andreas Kraag; Gylling, Anne Theil; Dideriksen, Kasper Juel; Siebner, Hartwig Roman; Mortensen, Erik Lykke; Kjaer, Michael

2016-01-01

Introduction Physical and cognitive function decline with age, accelerating during the 6th decade. Loss of muscle power (force×velocity product) is a dominant physical determinant for loss of functional ability, especially if the lower extremities are affected. Muscle strength training is known to maintain or even improve muscle power as well as physical function in older adults, but the optimal type of training for beneficial long-term training effects over several years is unknown. Moreover, the impact of muscle strength training on cognitive function and brain structure remains speculative. The primary aim of this randomised controlled trial is to compare the efficacy of two different 1 year strength training regimens on immediate and long-lasting improvements in muscle power in retirement-age individuals. Secondary aims are to evaluate the effect on muscle strength, muscle mass, physical and cognitive function, mental well-being, health-related quality of life and brain morphology. Methods and analysis The study includes 450 home-dwelling men and women (62–70 years). Participants are randomly allocated to (1) 1 year of supervised, centre-based heavy resistance training, (2) home-based moderate intensity resistance training or (3) habitual physical activity (control). Changes in primary (leg extensor power) and secondary outcomes are analysed according to the intention to treat principle and per protocol at 1, 2, 4, 7 and 10 years. Ethics and dissemination The study is expected to generate new insights into training-induced promotion of functional ability and independency after retirement and will help to formulate national recommendations regarding physical activity schemes for the growing population of older individuals in western societies. Results will be published in scientific peer-reviewed journals, in PhD theses and at public meetings. The study is approved by the Regional Ethical Committee (Capital Region, Copenhagen, Denmark, number H-3-2014-017). Trial registration number NCT02123641. PMID:27913559

Moderate volume of high relative training intensity produces greater strength gains compared with low and high volumes in competitive weightlifters.

PubMed

González-Badillo, Juan José; Izquierdo, Mikel; Gorostiaga, Esteban M

2006-02-01

The purpose of this study was to examine the effect of 3 volumes of heavy resistance, average relative training intensity (expressed as a percentage of 1 repetition maximum that represented the absolute kilograms lifted divided by the number of repetitions performed) programs on maximal strength (1RM) in Snatch (Sn), Clean & Jerk (C&J), and Squat (Sq). Twenty-nine experienced (>3 years), trained junior weightlifters were randomly assigned into 1 of 3 groups: low-intensity group (LIG; n = 12), moderate-intensity group (MIG; n = 9), and high-intensity group (HIG; n = 8). All subjects trained for 10 weeks, 4-5 days a week, in a periodized routine using the same exercises and training volume (expressed as total number of repetitions performed at intensities equal to or greater than 60% of 1RM), but different programmed total repetitions at intensities of >90-100% of 1RM for the entire 10-week period: LIG (46 repetitions), MIG (93 repetitions), and HIG (184 repetitions). During the training period, MIG and LIG showed a significant increase (p < 0.01-0.05) for C&J (10.5% and 3% for MIG and LIG, respectively) and Sq (9.5% and 5.3% for MIG and LIG, respectively), whereas in HIG the increase took place only in Sq (6.9%, p < 0.05). A calculation of effect sizes revealed greater strength gains in the MIG than in HIG or LIG. There were no significant differences between LIG and HIG training volume-induced strength gains. All the subjects in HIG were unable to fully accomplish the repetitions programmed at relative intensities greater than 90% of 1RM. The present results indicate that short-term resistance training using moderate volumes of high relative intensity tended to produce higher enhancements in weightlifting performance compared with low and high volumes of high relative training intensities of equal total volume in experienced, trained young weightlifters. Therefore, for the present population of weightlifters, it may be beneficial to use the MIG training protocol to improve the weightlifting program at least in a short-term (10 weeks) cycle of training.

Tendinous tissue properties after short- and long-term functional overload: Differences between controls, 12 weeks and 4 years of resistance training.

PubMed

Massey, G J; Balshaw, T G; Maden-Wilkinson, T M; Folland, J P

2018-04-01

The potential for tendinous tissues to adapt to functional overload, especially after several years of exposure to heavy-resistance training, is largely unexplored. This study compared the morphological and mechanical characteristics of the patellar tendon and knee extensor tendon-aponeurosis complex between young men exposed to long-term (4 years; n = 16), short-term (12 weeks; n = 15) and no (untrained controls; n = 39) functional overload in the form of heavy-resistance training. Patellar tendon cross-sectional area, vastus lateralis aponeurosis area and quadriceps femoris volume, plus patellar tendon stiffness and Young's modulus, and tendon-aponeurosis complex stiffness, were quantified with MRI, dynamometry and ultrasonography. As expected, long-term trained had greater muscle strength and volume (+58% and +56% vs untrained, both P < .001), as well as a greater aponeurosis area (+17% vs untrained, P < .01), but tendon cross-sectional area (mean and regional) was not different between groups. Only long-term trained had reduced patellar tendon elongation/strain over the whole force/stress range, whilst both short-term and long-term overload groups had similarly greater stiffness/Young's modulus at high force/stress (short-term +25/22%, and long-term +17/23% vs untrained; all P < .05). Tendon-aponeurosis complex stiffness was not different between groups (ANOVA, P = .149). Despite large differences in muscle strength and size, years of resistance training did not induce tendon hypertrophy. Both short-term and long-term overload demonstrated similar increases in high-force mechanical and material stiffness, but reduced elongation/strain over the whole force/stress range occurred only after years of overload, indicating a force/strain specific time-course to these adaptations. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Optimizing post activation potentiation for explosive activities in competitive sports

PubMed Central

Gołaś, Artur; Maszczyk, Adam; Mikołajec, Kazimierz; Stastny, Petr

2016-01-01

Abstract Post activation potentiation (PAP) has shown improved performance during movements requiring large muscular power output following contractions under near maximal load conditions. PAP can be described as an acute enhancement of performance or an enhancement of factors determining an explosive sports activity following a preload stimulus. In practice, PAP has been achieved by complex training, which involves a combination of a heavy loaded exercise followed by a biomechanically similar explosive activity, best if specific for a particular sport discipline. The main objective of this study was to investigate the effects of PAP on performance in explosive motor activities specific for basketball, luge and athletics throws. The novel approach to the experiments included individualized recovery time (IRT) between the conditioning exercise and the explosive activity. Additionally, the research groups were homogenous and included only competitive athletes of similar age and training experience. Thirty one well trained athletes from 3 different sport disciplines participated in the study. All athletes performed a heavy loaded conditioning activity (80-130%1RM) followed by a biomechanically similar explosive exercise, during which power (W) or the rate of power development (W/s/kg) was evaluated. The results of our experiment confirmed the effectiveness of PAP with well-trained athlets during explosive motor activities such as jumping, throwing and pushing. Additionally, our research showed that eccentric supramaximal intensities (130% 1RM) can be effective in eliciting PAP in strength trained athletes. Our experiments also showed that the IRT should be individualized because athletes differ in the strength level, training experience and muscle fiber structure. In the three experiments conducted with basketball players, track and field athletes and luge athletes, the optimal IRT equaled 6 min. This justifies the need to individualize the volume and intensity of the CA, and especially the IRT, between the CA and the explosive activity. PMID:28149397

Efficacy of the National Football League-225 Test to Track Changes in One Repetition Maximum Bench Press After Training in National Collegiate Athletic Association Division IA Football Players.

PubMed

Mann, J Bryan; Ivey, Pat A; Stoner, Josh D; Mayhew, Jerry L; Brechue, William F

2015-11-01

Numerous investigations have attested to the efficacy of the National Football League (NFL)-225 test to estimate one repetition maximum (1RM) bench press. However, no studies have assessed the efficacy of the test to track changes in strength across a training program. The purpose of this study was to determine the accuracy of the NFL-225 test for determining the change in 1RM bench press in National Collegiate Athletic Association Division IA college football players after training. Over a 4-year period, players (n = 203) were assessed before and after a 6-week off-season resistance program for 1RM bench press and repetitions completed with 102.3 kg (225 lbs). Test sessions typically occurred within 1 week of each other. Players significantly increased 1RM by 4.2 ± 8.6 kg and NFL-225 repetitions by 0.9 ± 2.3, although the effect size (ES) for each was trivial (ES = 0.03 and 0.07, respectively). National Football League 225 prediction equations had higher correlations with 1RM before training (intraclass correlation coefficient [ICC] = 0.95) than after training (ICC = 0.75). The correlation between the change in NFL-225 repetitions and change in 1RM was low and negative (r = -0.22, p < 0.02). Short-term heavy resistance training may alter the association between muscular strength and muscular endurance in college football players and render the NFL-225 test less effective in predicting the change in 1RM bench press strength after short-term training.

Scientific basis and practical aspects of creatine supplementation for athletes.

PubMed

Volek, Jeff S; Rawson, Eric S

2004-01-01

A large number of studies have been published on creatine supplementation over the last decade. Many studies show that creatine supplementation in conjunction with resistance training augments gains in muscle strength and size. The underlying physiological mechanism(s) to explain this ergogenic effect remain unclear. Increases in muscle fiber hypertrophy and myosin heavy chain expression have been observed with creatine supplementation. Creatine supplementation increases acute weightlifting performance and training volume, which may allow for greater overload and adaptations to training. Creatine supplementation may also induce a cellular swelling in muscle cells, which in turn may affect carbohydrate and protein metabolism. Several studies point to the conclusion that elevated intramuscular creatine can enhance glycogen levels but an effect on protein synthesis/degradation has not been consistently detected. As expected there is a distribution of responses to creatine supplementation that can be largely explained by the degree of creatine uptake into muscle. Thus, there is wide interest in methods to maximize muscle creatine levels. A carbohydrate or carbohydrate/protein-induced insulin response appears to benefit creatine uptake. In summary, the predominance of research indicates that creatine supplementation represents a safe, effective, and legal method to enhance muscle size and strength responses to resistance training.

The effect of five weeks of Tribulus terrestris supplementation on muscle strength and body composition during preseason training in elite rugby league players.

PubMed

Rogerson, Shane; Riches, Christopher J; Jennings, Carl; Weatherby, Robert P; Meir, Rudi A; Marshall-Gradisnik, Sonya M

2007-05-01

Tribulus terrestris is an herbal nutritional supplement that is promoted to produce large gains in strength and lean muscle mass in 5-28 days (15, 18). Although some manufacturers claim T. terrestris will not lead to a positive drug test, others have suggested that T. terrestris may increase the urinary testosterone/epitestosterone (T/E) ratio, which may place athletes at risk of a positive drug test. The purpose of the study was to determine the effect of T. terrestris on strength, fat free mass, and the urinary T/E ratio during 5 weeks of preseason training in elite rugby league players. Twenty-two Australian elite male rugby league players (mean +/- SD; age = 19.8 +/- 2.9 years; weight = 88.0 +/- 9.5 kg) were match-paired and randomly assigned in a double-blind manner to either a T. terrestris (n = 11) or placebo (n = 11) group. All subjects performed structured heavy resistance training as part of the club's preseason preparations. A T. terrestris extract (450 mg.d(-1)) or placebo capsules were consumed once daily for 5 weeks. Muscular strength, body composition, and the urinary T/E ratio were monitored prior to and after supplementation. After 5 weeks of training, strength and fat free mass increased significantly without any between-group differences. No between-group differences were noted in the urinary T/E ratio. It was concluded that T. terrestris did not produce the large gains in strength or lean muscle mass that many manufacturers claim can be experienced within 5-28 days. Furthermore, T. terrestris did not alter the urinary T/E ratio and would not place an athlete at risk of testing positive based on the World Anti-Doping Agency's urinary T/E ratio limit of 4:1.

Effects of 28 days of resistance exercise while consuming commercially available pre- and post-workout supplements, NO-Shotgun® and NO-Synthesize® on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers in males

PubMed Central

2011-01-01

Purpose The effects of 28 days of heavy resistance training while ingesting the pre- and post-workout supplements, NO-Shotgun® and NO-Synthesize® were determined on body composition, muscle strength and mass, markers of protein synthesis, and clinical safety markers. Methods Nineteen non-resistance-trained males participated in a resistance training program 4 times/week for 28 days while either ingesting 27 g/day of carbohydrate (CARB) or NO-Shotgun® 30 min pre-exercise and 27 g/day of carbohydrate or NO- Synthesize® 30 min post-exercise (NOSS). Data were analyzed with separate 2 × 2 ANOVA (p < 0.05). Results Total body mass was increased in both groups (p = 0.001), but not different between groups. Fat mass was unchanged with CARB, but NOSS decreased fat mass (p = 0.026). Both groups increased fat-free mass (p = 0.001); however, the increases were greater with NOSS (p = 0.023). NOSS underwent greater increases in upper-body (p = 0.023) and lower-body (p = 0.035) strength than CARB. Myofibrillar protein significantly increased in both groups (p = 0.041), with NOSS being greater than CARB (p = 0.049). All of the MHC isoforms were significantly increased in both groups; however, NOSS was greater than CARB for MHC 1 (p = 0.013) and MHC 2A (p = 0.046). All of the myogenic regulatory factors were significantly increased in both groups; however, NOSS was greater than CARB for Myo-D (p = 0.038) and MRF-4 (p = 0.001). For the whole blood and serum clinical chemistry markers, all variables remained within normal clinical ranges. Conclusions Heavy resistance training for 28 days, with NO-Shotgun® and NO-Synthesize® ingested before and after exercise, respectively, significantly improved body composition and increased muscle mass and performance without abnormally impacting any of the clinical chemistry markers. PMID:22050827

Some engineering properties of heavy concrete added silica fume

DOE Office of Scientific and Technical Information (OSTI.GOV)

Akkaş, Ayşe; Başyiğit, Celalettin; Esen, Serap

Many different types of building materials have been used in building construction for years. Heavy concretes can be used as a building material for critical building as it can contain a mixture of many heavy elements. The barite itself for radiation shielding can be used and also in concrete to produce the workable concrete with a maximum density and adequate structural strength. In this study, some engineering properties like compressive strength, elasticity modules and flexure strength of heavy concretes’ added Silica fume have been investigated.

Resistance exercise load does not determine training-mediated hypertrophic gains in young men

PubMed Central

Mitchell, Cameron J.; Churchward-Venne, Tyler A.; West, Daniel W. D.; Burd, Nicholas A.; Breen, Leigh; Baker, Steven K.

2012-01-01

We have reported that the acute postexercise increases in muscle protein synthesis rates, with differing nutritional support, are predictive of longer-term training-induced muscle hypertrophy. Here, we aimed to test whether the same was true with acute exercise-mediated changes in muscle protein synthesis. Eighteen men (21 ± 1 yr, 22.6 ± 2.1 kg/m2; means ± SE) had their legs randomly assigned to two of three training conditions that differed in contraction intensity [% of maximal strength (1 repetition maximum)] or contraction volume (1 or 3 sets of repetitions): 30%-3, 80%-1, and 80%-3. Subjects trained each leg with their assigned regime for a period of 10 wk, 3 times/wk. We made pre- and posttraining measures of strength, muscle volume by magnetic resonance (MR) scans, as well as pre- and posttraining biopsies of the vastus lateralis, and a single postexercise (1 h) biopsy following the first bout of exercise, to measure signaling proteins. Training-induced increases in MR-measured muscle volume were significant (P < 0.01), with no difference between groups: 30%-3 = 6.8 ± 1.8%, 80%-1 = 3.2 ± 0.8%, and 80%-3= 7.2 ± 1.9%, P = 0.18. Isotonic maximal strength gains were not different between 80%-1 and 80%-3, but were greater than 30%-3 (P = 0.04), whereas training-induced isometric strength gains were significant but not different between conditions (P = 0.92). Biopsies taken 1 h following the initial resistance exercise bout showed increased phosphorylation (P < 0.05) of p70S6K only in the 80%-1 and 80%-3 conditions. There was no correlation between phosphorylation of any signaling protein and hypertrophy. In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure resulted in similar hypertrophy as a heavy load lifted to failure. PMID:22518835

Exercise-training intervention studies in competitive swimming.

PubMed

Aspenes, Stian Thoresen; Karlsen, Trine

2012-06-01

Competitive swimming has a long history and is currently one of the largest Olympic sports, with 16 pool events. Several aspects separate swimming from most other sports such as (i) the prone position; (ii) simultaneous use of arms and legs for propulsion; (iii) water immersion (i.e. hydrostatic pressure on thorax and controlled respiration); (iv) propulsive forces that are applied against a fluctuant element; and (v) minimal influence of equipment on performance. Competitive swimmers are suggested to have specific anthropometrical features compared with other athletes, but are nevertheless dependent on physiological adaptations to enhance their performance. Swimmers thus engage in large volumes of training in the pool and on dry land. Strength training of various forms is widely used, and the energetic systems are addressed by aerobic and anaerobic swimming training. The aim of the current review was to report results from controlled exercise training trials within competitive swimming. From a structured literature search we found 17 controlled intervention studies that covered strength or resistance training, assisted sprint swimming, arms-only training, leg-kick training, respiratory muscle training, training the energy delivery systems and combined interventions across the aforementioned categories. Nine of the included studies were randomized controlled trials. Among the included studies we found indications that heavy strength training on dry land (one to five repetitions maximum with pull-downs for three sets with maximal effort in the concentric phase) or sprint swimming with resistance towards propulsion (maximal pushing with the arms against fixed points or pulling a perforated bowl) may be efficient for enhanced performance, and may also possibly have positive effects on stroke mechanics. The largest effect size (ES) on swimming performance was found in 50 m freestyle after a dry-land strength training regimen of maximum six repetitions across three sets in relevant muscle-groups (ES 1.05), and after a regimen of resisted- and assisted-sprint training with elastic surgical tubes (ES 1.21). Secondly, several studies suggest that high training volumes do not pose any immediate advantage over lower volumes (with higher intensity) for swim performance. Overall, very few studies were eligible for the current review although the search strategy was broad and fairly liberal. The included studies predominantly involved freestyle swimming and, overall, there seems to be more questions than answers within intervention-based competitive swimming research. We believe that this review may encourage other researchers to pursue the interesting topics within the physiology of competitive swimming.

Effects of in-competitive season power-oriented and heavy resistance lower-body training on performance of elite female water polo players.

PubMed

Veliz, Rafael R; Suarez-Arrones, Luis; Requena, Bernardo; Haff, G Gregory; Feito, Javier; Sáez de Villarreal, Eduardo

2015-02-01

We examined the effect of 16 weeks of lower-body resistance and power-oriented training on key performance measures of elite female water polo players. Twenty-one players were randomly assigned to 2 groups: control group (C) who did in-water training only and a lower body strength (LBS) group, who performed resistance (full squat and split squat) and jump and power-oriented lower-body training (countermovement jump [CMJ] loaded and CMJ) sessions (twice per week) in addition to the same in-water training. In-water training was conducted 5 days per week for a total of 16 weeks. Twenty-meter maximal sprint swim (MSS), lower-body strength during 1 repetition maximum (1RM) full squat (FS), in-water boost and CMJ, and Throwing speed (ThS) were measured before and after the training. Pretraining results showed no statistically significant differences between the groups in any of the variables tested. After 16 weeks, no statistically significant improvement was found in any of the variables measured in the C group, however, significant improvement was found in the LBS group: in-water boost (4.6 cm, 12.02%, effect size [ES] = 1.02), CMJ (2.4 cm, 8.66%, ES = 0.85), FS (12.7 kg, 20.99%, ES = 2.41), and ThS (3.4 km·h, 6.86%, ES = 3.44). Lower-body resistance and power-oriented training in female water polo players for 16 weeks produced significant improvements in performance qualities highly specific to water polo performance. Therefore, we propose modifications to current training methodology for female water polo players to include resistance and power-oriented training during the competitive season in this sport.

Muscle preservation in long duration space missions: The eccentric factor

NASA Technical Reports Server (NTRS)

Buchanan, Paul; Dudley, Gary A.; Tesch, Per A.; Hather, Bruce M.

1990-01-01

In our quest to understand, and eventually prevent, the loss of muscle strength and mass that occurs during prolonged periods in microgravity, we have organized our research approach by systems and useful terrestrial analogs. Our hypothesis was that: The eccentric movement, or lengthening component, of dynamic, resistive exercise, is required for the production of the greatest gains in strength and muscle hypertrophy in the most metabolically efficient, and time effective manner. The exercises selected were leg presses, leg (knee) extensions, and hamstring curls. In this 30 week study, 38 male subjects, between the ages of 25 and 50, were divided into four groups. One group performed 5 sets of 8-12 repetitions per set of conventional concentric/eccentric (CON/ECC) exercises. Another group performed only the concentric (CON) movement on the same schedule. The third group performed twice the number of sets in the concentric only mode (CON/CON), and the last group served as controls. We interpret these data as convincing evidence that the eccentric component of heavy resistance training is required along with the concentric for the most effective increase in strength and muscle fiber size in the least time. We also conclude that such heavy exercise of any such muscle group need not consume inordinately long periods of time, and is quite satisfactorily effective when performed on 72 hour centers.

Advanced Resistive Exercise Device

NASA Technical Reports Server (NTRS)

Raboin, Jasen; Niebuhr, Jason; Cruz, Santana; Lamoreaux, chris

2007-01-01

The advanced resistive exercise device (ARED), now at the prototype stage of development, is a versatile machine that can be used to perform different customized exercises for which, heretofore, it has been necessary to use different machines. Conceived as a means of helping astronauts and others to maintain muscle and bone strength and endurance in low-gravity environments, the ARED could also prove advantageous in terrestrial settings (e.g., health clubs and military training facilities) in which many users are exercising simultaneously and there is heavy demand for use of exercise machines.

Heavy Duty Tireman. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

McColman, Don

This training outline for heavy duty tiremen, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Physical Training Strategies for Military Women's Performance Optimization in Combat-Centric Occupations.

PubMed

Nindl, Bradley C

2015-11-01

The physiological differences, particularly of upper-body strength and power, between women and men, and the rigors of combat-centric occupational demands would seem to place women at a significant disadvantage, as the U.S. military opens up previously closed combat-arms military occupational specialties (MOSs) to women. This inherent disadvantage can be significantly mitigated by implementing effective and comprehensive physical training (PT) regimens for women targeting those fitness components most critical for those tasks considered most essential for solider warfighting duties (i.e., strength and power). Regrettably, the military historical and legacy overemphasis on aerobic fitness and on "field expediency" as the major criteria for implementing training have limited the extent to which the military has fully operationalized state-of-the-science PT policies. This continued legacy approach could be problematic regarding fully enhancing women's abilities to perform physically demanding combat-centric occupations and could place the successful integration of women into ground combat MOSs at significant risk. Seminal studies from the literature indicate that (a) a minimum of 6 months of periodized combined resistance/endurance training preparedness is recommended for untrained women considering entering combat-arms MOS training; (b) any comprehensive PT program should incorporate and emphasize progressive load carriage training; (c) a greater emphasis on upper body on strength/power development in military women is needed; (d) heavy resistance training in the range of 3-8 repetition maximum sets should be incorporated into training programs to target type II motor units and muscle fibers (those fibers that produce the most force and have the greatest capacity to hypertrophy); (e) low-volume, high-intensity interval training should be considered as a time-efficient training method to improve aerobic fitness while protecting against lower-body musculoskeletal injuries; (f) flexible nonlinear periodized programs should be considered to best accommodate the unpredictability and operational functional needs of the military training environment; and (g) serious consideration should be given to revamping the manner in which the military conducts physical readiness training, with a departure from "field expediency" as the major criteria for determining PT policies. With an increased emphasis on the human dimension of soldiering and concerted strategic, operational, and tactical efforts to maximize individual physical readiness and performance, the science of training physiology exists to leverage and better physically prepare women as they enter more combat-centric occupations.

Fake ID ownership and heavy drinking in underage college students: prospective findings.

PubMed

Martinez, Julia A; Rutledge, Patricia C; Sher, Kenneth J

2007-06-01

The authors examined the ownership of false identification (fake ID) for the purpose of obtaining alcohol and the relation of fake ID ownership to heavy drinking in a longitudinal sample of college students under 21 years of age. A sample of 3,720 undergraduates was assessed the summer prior to college entrance and during the 4 semesters comprising freshman and sophomore years. Regression analyses were used to estimate bidirectional relations between consumption and fake ID ownership. Sex, Greek membership, and prior drinking were controlled. Results showed that fake ID ownership increased over time (12.5% pre-college to 32.2% fourth semester) and that Greek members were more likely than others to own fake IDs. Fake ID ownership predicted concurrent and next-semester heavy drinking with increasing strength over time. Also, the acquisition (onset) of fake ID ownership at each time point was predicted by previous-semester consumption. When traditional, robust risk factors of consumption are controlled, fake ID ownership meaningfully relates to heavy drinking in college. It thus presents a significant public health problem, addressable through training for alcohol servers and retailers, punitive measures toward fake ID owners, and other possible interventions.

Short-term effects on lower-body functional power development: weightlifting vs. vertical jump training programs.

PubMed

Tricoli, Valmor; Lamas, Leonardo; Carnevale, Roberto; Ugrinowitsch, Carlos

2005-05-01

Among sport conditioning coaches, there is considerable discussion regarding the efficiency of training methods that improve lower-body power. Heavy resistance training combined with vertical jump (VJ) training is a well-established training method; however, there is a lack of information about its combination with Olympic weightlifting (WL) exercises. Therefore, the purpose of this study was to compare the short-term effects of heavy resistance training combined with either the VJ or WL program. Thirty-two young men were assigned to 3 groups: WL = 12, VJ = 12, and control = 8. These 32 men participated in an 8-week training study. The WL training program consisted of 3 x 6RM high pull, 4 x 4RM power clean, and 4 x 4RM clean and jerk. The VJ training program consisted of 6 x 4 double-leg hurdle hops, 4 x 4 alternated single-leg hurdle hops, 4 x 4 single-leg hurdle hops, and 4 x 4 40-cm drop jumps. Additionally, both groups performed 4 x 6RM half-squat exercises. Training volume was increased after 4 weeks. Pretesting and posttesting consisted of squat jump (SJ) and countermovement jump (CMJ) tests, 10- and 30-m sprint speeds, an agility test, a half-squat 1RM, and a clean-and-jerk 1RM (only for WL). The WL program significantly increased the 10-m sprint speed (p < 0.05). Both groups, WL and VJ, increased CMJ (p < 0.05), but groups using the WL program increased more than those using the VJ program. On the other hand, the group using the VJ program increased its 1RM half-squat strength more than the WL group (47.8 and 43.7%, respectively). Only the WL group improved in the SJ (9.5%). There were no significant changes in the control group. In conclusion, Olympic WL exercises seemed to produce broader performance improvements than VJ exercises in physically active subjects.

Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis

PubMed Central

Behm, David G.; Young, James D.; Whitten, Joseph H. D.; Reid, Jonathan C.; Quigley, Patrick J.; Low, Jonathan; Li, Yimeng; Lima, Camila D.; Hodgson, Daniel D.; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs

2017-01-01

Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral landings and propulsions associated with sprinting. Based on this meta-analysis, strength training should be incorporated prior to power training in order to establish an adequate foundation of strength for power training activities. PMID:28713281

Effectiveness of Traditional Strength vs. Power Training on Muscle Strength, Power and Speed with Youth: A Systematic Review and Meta-Analysis.

PubMed

Behm, David G; Young, James D; Whitten, Joseph H D; Reid, Jonathan C; Quigley, Patrick J; Low, Jonathan; Li, Yimeng; Lima, Camila D; Hodgson, Daniel D; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs

2017-01-01

Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral landings and propulsions associated with sprinting. Based on this meta-analysis, strength training should be incorporated prior to power training in order to establish an adequate foundation of strength for power training activities.

Exercise Responses to Gravity-Independent Flywheel Aerobic and Resistance Training.

PubMed

Owerkowicz, Tomasz; Cotter, Joshua A; Haddad, Fadia; Yu, Alvin M; Camilon, Marinelle L; Hoang, Theresa N; Jimenez, Daniel J; Kreitenberg, Arthur; Tesch, Per A; Caiozzo, Vincent J; Adams, Gregory R

2016-02-01

Although several exercise systems have been developed to mitigate the physiological deconditioning that occurs in microgravity, few have the capacity to positively impact multiple physiological systems and still meet the volume/mass requirements needed for missions beyond low Earth orbit. The purpose of this study was to test the gravity-independent Multi-Mode Exercise Device (M-MED) for both resistance (RE) and aerobic (AE) training stimuli. Eight men and nine women (mean age 22.0 ± 0.4 yr) completed 5 wk of training on the M-MED: RE 4 × 7 squats 2 d/wk, and AE 4 × 4-min rowing bouts at ∼90% Vo2max 3 d/wk. Pre- and post-training data collection included an aerobic capacity test, MR imaging, strength testing, and vastus lateralis muscle biopsy. Vo2max increased 8%, 3RM strength 18%, and quadriceps femoris cross-sectional area (CSA) 10%. Knee extensor strength increased at all isokinetic speeds tested. Subjects also demonstrated improved fatigue resistance in knee extension. At the cellular and molecular level, the biopsy revealed increases in mixed myofiber CSA (13%), citrate synthase activity (26%), total RNA concentration (24%), IGF-I mRNA (77%), and Type IIa myosin heavy chain (MHC) mRNA (8%), and a concomitant decrease in Type IIx MHC mRNA (-23%). None of the changes were gender-specific. Both the functional outcomes and biomarker changes indicate that a very low volume of M-MED exercise results in robust adaptation in the cardiovascular and musculoskeletal systems. The M-MED has the potential to provide a wide range of countermeasure exercises and should be considered for testing in ground-based spaceflight simulation.

Skeletal Muscle Fatigability and Myosin Heavy Chain Fiber Type in Resistance Trained Men.

PubMed

Bagley, James R; McLeland, Kathryn A; Arevalo, Jose A; Brown, Lee E; Coburn, Jared W; Galpin, Andrew J

2017-03-01

Bagley, JR, McLeland, KA, Arevalo, JA, Brown, LE, Coburn, JW, and Galpin, AJ. Skeletal muscle fatigability and myosin heavy chain fiber type in resistance trained men. J Strength Cond Res 31(3): 602-607, 2017-Forty years ago, Thorstensson and Karlsson in 1976 described the link between muscle fatigability and fiber type, finding that more fast-twitch fibers were associated with a quicker onset of quadriceps fatigue. This provided the foundation for the Classic Thorstensson Test of fatigability and subsequent noninvasive fiber type prediction equation. This equation was developed with data from recreationally active (REC) men but has been implemented in participants with heterogeneous physical activity/exercise backgrounds. The accuracy of this approach in resistance trained (RET) men has not been established. Moreover, muscle fiber typing techniques have evolved considerably since this seminal work. Therefore, we reexamined this relationship using RET men and a more sensitive fiber typing method (single fiber myosin heavy chain [MHC] isoform classification). Fifteen RET men (age = 24.8 ± 1.3 years) performed maximal knee extensions (via isokinetic dynamometry) to determine peak torque (PT) and quadriceps fatigue percentage (FP) after 30 and 50 repetitions. Vastus lateralis (VL) single fiber MHC type was determined and fibers were grouped as %Fast (expressing MHC IIa, IIa/IIX, or IIx; no MHC I containing fibers). Resistance trained men exhibited 46% greater PT (RET = 207 ± 28 N·m vs. REC = 130 ± 8 N·m) and 28% more %Fast (RET = 61 ± 4% vs. REC = 44 ± 4%) than REC men. Additionally, RET men had a relatively homogeneous FP (64 ± 1%) ranging from 53 to 72%. No relationship was found between FP and MHC fiber type (R = 0.01, p > 0.05). The Classic Thorstensson Test may not accurately estimate VL fiber type composition in RET men, highlighting the (a) unique phenotypical/functional adaptations induced by chronic RET and (b) the need for more sensitive cellular/molecular analyses in RET muscle.

Performance and Endocrine Responses to Differing Ratios of Concurrent Strength and Endurance Training.

PubMed

Jones, Thomas W; Howatson, Glyn; Russell, Mark; French, Duncan N

2016-03-01

The present study examined functional strength and endocrine responses to varying ratios of strength and endurance training in a concurrent training regimen. Thirty resistance trained men completed 6 weeks of 3 d·wk of (a) strength training (ST), (b) concurrent strength and endurance training ratio 3:1 (CT3), (c) concurrent strength and endurance training ratio 1:1 (CT1), or (d) no training (CON). Strength training was conducted using whole-body multijoint exercises, whereas endurance training consisted of treadmill running. Assessments of maximal strength, lower-body power, and endocrine factors were conducted pretraining and after 3 and 6 weeks. After the intervention, ST and CT3 elicited similar increases in lower-body strength; furthermore, ST resulted in greater increases than CT1 and CON (all p ≤ 0.05). All training conditions resulted in similar increases in upper-body strength after training. The ST group observed greater increases in lower-body power than all other conditions (all p ≤ 0.05). After the final training session, CT1 elicited greater increases in cortisol than ST (p = 0.008). When implemented as part of a concurrent training regimen, higher volumes of endurance training result in the inhibition of lower-body strength, whereas low volumes do not. Lower-body power was attenuated by high and low frequencies of endurance training. Higher frequencies of endurance training resulted in increased cortisol responses to training. These data suggest that if strength development is the primary focus of a training intervention, frequency of endurance training should remain low.

Effects of Strength vs. Ballistic-Power Training on Throwing Performance

PubMed Central

Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos

2013-01-01

The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key points Ballistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks. In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance. The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters. PMID:24149736

Effects of Strength vs. Ballistic-Power Training on Throwing Performance.

PubMed

Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos

2013-01-01

The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05). Muscle fibre Cross Sectional Area (fCSA) increased in all fibre types after Strength training by 19-26% (p < 0.05), while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (%) decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters.

Safety of strength training in premenopausal women: musculoskeletal injuries from a two-year randomized trial.

PubMed

Warren, Meghan; Schmitz, Kathryn H

2009-01-01

The health benefits of strength training must be weighed against risks, including injuries. A prior study observed 4.2 injuries that limited usual activities for a day per 1000 strength training sessions among men and women. The analysis herein explores the incidence rates of musculoskeletal injuries from strength training in women. Randomized controlled trial. SETTING; Free-living community. A total of 163 injury-free, overweight, sedentary, premenopausal women aged 25 to 44 years. Two years of strength training (n = 81) or standard care (n = 82). The intervention followed published guidelines (U.S. Department of Health and Human Services) with hypothesized injury prevention strategies. An injury survey was administered at years 1 and 2. Injury was defined as physical activity or strength training associated injuries that limited daily activities for 1 week or more. Denominators for rate calculation were accelerometer-measured physical activity and strength training attendance (strength training only). The between-group probability of injuries was assessed using generalized estimating equations. Injury incidence rates were higher in strength training compared with standard care. In strength training, the injury rates were 3.6 per 1000 strength training sessions (95% confidence interval: 2.5-4.8 per 1000) for physical activity-related injuries, and 2.6 per 1000 (95% confidence interval: 1.5-3.6 per 1000) for strength training-related injuries. Injury rates varied by definition and denominator. Strength training had lower injury rates than previously reported, providing preliminary support for the prevention strategies. The finding of strength training injuries underscores the need for balancing the benefits against the potential risks of this exercise modality.

Cross-education of wrist extensor strength is not influenced by non-dominant training in right-handers.

PubMed

Coombs, Timothy A; Frazer, Ashlyn K; Horvath, Deanna M; Pearce, Alan J; Howatson, Glyn; Kidgell, Dawson J

2016-09-01

Cross-education of strength has been proposed to be greater when completed by the dominant limb in right handed humans. We investigated whether the direction of cross-education of strength and corticospinal plasticity are different following right or left limb strength training in right-handed participants. Changes in strength, muscle thickness and indices of corticospinal plasticity were analyzed in 23 adults who were exposed to 3-weeks of either right-hand strength training (RHT) or left-hand strength training (LHT). Maximum voluntary wrist extensor strength in both the trained and untrained limb increased, irrespective of which limb was trained, with TMS revealing reduced corticospinal inhibition. Cross-education of strength was not limited by which limb was trained and reduced corticospinal inhibition was not just confined to the trained limb. Critically, from a behavioral perspective, the magnitude of cross-education was not limited by which limb was trained.

Sources of strength-training information and strength-training behavior among Japanese older adults.

PubMed

Harada, Kazuhiro; Shibata, Ai; Lee, Euna; Oka, Koichiro; Nakamura, Yoshio

2016-03-01

The promotion of strength training is now recognized as an important component of public health initiatives for older adults. To develop successful communication strategies to increase strength-training behavior among older adults, the identification of effective communication channels to reach older adults is necessary. This study aimed to identify the information sources about strength training that were associated with strength-training behaviors among Japanese older adults. The participants were 1144 adults (60-74 years old) randomly sampled from the registry of residential addresses. A cross-sectional questionnaire survey was conducted. The independent variables were sources of strength-training information (healthcare providers, friends, families, radio, television, newspapers, newsletters, posters, books, magazines, booklets, the Internet, lectures, other sources), and the dependent variable was regular strength-training behavior. Logistic regression analysis was used to identify potential relationships. After adjusting for demographic factors and all other information sources, strength-training information from healthcare providers, friends, books and the Internet were positively related to regular strength-training behavior. The findings of the present study contribute to a better understanding of strength-training behavior and the means of successful communication directed at increasing strength training among older adults. The results suggest that healthcare providers, friends, books and the Internet are effective methods of communication for increasing strength-training behaviors among older adults. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effects of strength training, detraining and retraining in muscle strength, hypertrophy and functional tasks in older female adults.

PubMed

Correa, Cleiton S; Cunha, Giovani; Marques, Nise; Oliveira-Reischak, Ãlvaro; Pinto, Ronei

2016-07-01

Previous studies presented different results regarding the maintenance time of muscular adaptations after strength training and the ability to resume the gains on muscular performance after resumption of the training programme. This study aimed to verify the effect of strength training on knee extensors and elbow flexor muscle strength, rectus femoris muscle volume and functional performance in older female adults after 12 weeks of strength training, 1 year of detraining and followed by 12 weeks of retraining. Twelve sedentary older women performed 12 weeks of strength training, 1 year of detraining and 12 weeks of retraining. The strength training was performed twice a week, and the assessment was made four times: at the baseline, after the strength training, after the detraining and after the retraining. The knee extensor and elbow flexor strength, rectus femoris muscle volume and functional task were assessed. Strength of knee extensor and elbow flexor muscles, rectus femoris muscle volume and 30-s sit-to-stand increased from baseline to post-training (respectively, 40%, 70%, 38% and 46%), decreased after detraining (respectively, -36%, -64%, -35% and -43%) and increased again these parameters after retraining (35%, 68%, 36% and 42%). Strength training induces gains on strength and hypertrophy, also increased the performance on functional tasks after the strength training. The stoppage of the strength caused strength loss and reduction of functional performance. The resumption of the strength training promoted the same gains of muscular performance in older female adults. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.

Establishment and verification of three-dimensional dynamic model for heavy-haul train-track coupled system

NASA Astrophysics Data System (ADS)

Liu, Pengfei; Zhai, Wanming; Wang, Kaiyun

2016-11-01

For the long heavy-haul train, the basic principles of the inter-vehicle interaction and train-track dynamic interaction are analysed firstly. Based on the theories of train longitudinal dynamics and vehicle-track coupled dynamics, a three-dimensional (3-D) dynamic model of the heavy-haul train-track coupled system is established through a modularised method. Specifically, this model includes the subsystems such as the train control, the vehicle, the wheel-rail relation and the line geometries. And for the calculation of the wheel-rail interaction force under the driving or braking conditions, the large creep phenomenon that may occur within the wheel-rail contact patch is considered. For the coupler and draft gear system, the coupler forces in three directions and the coupler lateral tilt angles in curves are calculated. Then, according to the characteristics of the long heavy-haul train, an efficient solving method is developed to improve the computational efficiency for such a large system. Some basic principles which should be followed in order to meet the requirement of calculation accuracy are determined. Finally, the 3-D train-track coupled model is verified by comparing the calculated results with the running test results. It is indicated that the proposed dynamic model could simulate the dynamic performance of the heavy-haul train well.

Unique aspects of competitive weightlifting: performance, training and physiology.

PubMed

Storey, Adam; Smith, Heather K

2012-09-01

Weightlifting is a dynamic strength and power sport in which two, multijoint, whole-body lifts are performed in competition; the snatch and clean and jerk. During the performance of these lifts, weightlifters have achieved some of the highest absolute and relative peak power outputs reported in the literature. The training structure of competitive weightlifters is characterized by the frequent use of high-intensity resistance exercise movements. Varied coaching and training philosophies currently exist around the world and further research is required to substantiate the best type of training programme for male and female weightlifters of various age groups. As competitive weightlifting is contested over eight male and seven female body weight categories, the anthropometric characteristics of the athletes widely ranges. The body compositions of weightlifters are similar to that of athletes of comparable body mass in other strength and power sports. However, the shorter height and limb lengths of weightlifters provide mechanical advantages when lifting heavy loads by reducing the mechanical torque and the vertical distance that the barbell must be displaced. Furthermore, the shorter body dimensions coincide with a greater mean skeletal muscle cross-sectional area that is advantageous to weightlifting performance. Weightlifting training induces a high metabolic cost. Although dietary records demonstrate that weightlifters typically meet their required daily energy intake, weightlifters have been shown to over consume protein and fat at the expense of adequate carbohydrate. The resulting macronutrient imbalance may not yield optimal performance gains. Cross-sectional data suggest that weightlifting training induces type IIX to IIA fibre-type transformation. Furthermore, weightlifters exhibit hypertrophy of type II fibres that is advantageous to weightlifting performance and maximal force production. As such, the isometric peak force and contractile rate of force development of weightlifters is ~15-20% and ~13-16% greater, respectively, than in other strength and power athletes. In addition, weightlifting training has been shown to reduce the typical sex-related difference in the expression of neuromuscular strength and power. However, this apparent sex-related difference appears to be augmented with increasing adult age demonstrating that women undergo a greater age-related decline in muscle shortening velocity and peak power when compared with men. Weightlifting training and competition has been shown to induce significant structural and functional adaptations of the cardiovascular system. The collective evidence shows that these adaptations are physiological as opposed to pathological. Finally, the acute exercise-induced testosterone, cortisol and growth hormone responses of weightlifters have similarities to that of following conventional strength and hypertrophy protocols involving large muscle mass exercises. The routine assessment of the basal testosterone : cortisol ratio may be beneficial when attempting to quantify the adaptive responses to weightlifting training. As competitive weightlifting is becoming increasingly popular around the world, further research addressing the physiological responses and adaptations of female weightlifters and younger (i.e. ≤17 years of age) and older (i.e. ≥35 years of age) weightlifters of both sexes is required.

Effects of resistance training on running economy and cross-country performance.

PubMed

Barnes, Kyle R; Hopkins, Will G; McGuigan, Michael R; Northuis, Mark E; Kilding, Andrew E

2013-12-01

Heavy-resistance training and plyometric training offer distinct physiological and neuromuscular adaptations that could enhance running economy and, consequently, distance-running performance. To date, no studies have examined the effect of combining the two modes of training on running economy or performance. Fifty collegiate male and female cross-country runners performed a 5-km time trial and a series of laboratory-based tests to determine aerobic, anthropometric, biomechanical, and neuromuscular characteristics. Thereafter, each athlete participated in a season of six to eight collegiate cross-country races for 13 wk. After the first 4 wk, athletes were randomly assigned to either heavy-resistance or plyometric plus heavy-resistance training. Five days after completing their final competition, runners repeated the same set of laboratory tests. We also estimated the effects of the intervention on competition performance throughout the season using athletes of other teams as controls. Heavy-resistance training produced small-moderate improvements in peak speed, running economy, and neuromuscular characteristics relative to plyometric resistance training, whereas changes in biomechanical measures favored plyometric resistance training. Men made less gains than women in most tests. Both treatments had possibly harmful effects on competition times in men (mean = 0.5%; 90% confidence interval = ±1.2%), but there may have been benefit for some individuals. Both treatments were likely beneficial for all women (-1.2%; ±1.3%), but heavy-resistance training was possibly better than plyometric resistance training. The changes in laboratory-based parameters related to distance-running performance were consistent with the changes in competition times for women but only partly for men. Our data indicate that women should include heavy-resistance training in their programs, but men should be cautious about using it in season until more research establishes whether certain men are positive or negative responders.

Heavy Duty Equipment Mechanic. Apprenticeship Training Standards = Mecanicien d'equipement lourd. Normes de formation en apprentissage.

ERIC Educational Resources Information Center

Ontario Ministry of Skills Development, Toronto.

These training standards for heavy duty equipment mechanics are intended to be used by apprentice/trainees, instructors, and companies in Ontario, Canada, as a blueprint for training or as a prerequisite for accreditation/certification. The training standards identify skills required for this occupation and its related training program. They are…

Commercial Training Issues: Heavy Duty Alternative Fuel Vehicles.

ERIC Educational Resources Information Center

Eckert, Douglas

The needs and opportunities in the heavy-duty alternative fuel vehicle training arena were examined in an informal ethnographic study of the appropriateness and effectiveness of the instructional materials currently being used in such training. Interviews were conducted with eight instructors from the National Alternative Fuels Training Program…

Heavy Construction Equipment Mechanic; A Suggested Guide for a Training Course.

ERIC Educational Resources Information Center

Division of Manpower Development and Training. , BAVT.

Prepared by a technical writer for the Division of Manpower Development and Training, this guide is intended to aid instructors, supervisors, and administrators of vocational education and manpower training programs in establishing training programs for mechanics and technicians entering the occupation of servicing heavy construction equipment.…

Individual responses to combined endurance and strength training in older adults.

PubMed

Karavirta, Laura; Häkkinen, Keijo; Kauhanen, Antti; Arija-Blázquez, Alfredo; Sillanpää, Elina; Rinkinen, Niina; Häkkinen, Arja

2011-03-01

A combination of endurance and strength training is generally used to seek further health benefits or enhanced physical performance in older adults compared with either of the training modes alone. The mean change within a training group, however, may conceal a wide range of individual differences in the responses. The purpose, therefore, was to examine the individual trainability of aerobic capacity and maximal strength, when endurance and strength training are performed separately or concurrently. For this study, 175 previously untrained volunteers, 89 men and 86 women between the ages of 40 and 67 yr, completed a 21-wk period of either strength training (S) twice a week, endurance training (E) twice a week, combined training (ES) four times per week, or served as controls. Training adaptations were quantified as peak oxygen uptake (VO2peak) in a bicycle ergometer test to exhaustion and maximal isometric bilateral leg extension force (MVC) in a dynamometer. A large range in training responses, similar to endurance or strength training alone, was also observed with combined endurance and strength training in both ΔVO2peak (from -8% to 42%) and ΔMVC (from -12% to 87%). There were no significant correlations between the training responses in VO2peak and MVC in the E, S, or especially in the ES group, suggesting that the same subjects did not systematically increase both aerobic capacity and maximal strength. The goal of combined endurance and strength training--increasing both aerobic capacity and maximal strength simultaneously--was only achieved by some of the older subjects. New means are needed to personalize endurance, strength, and especially combined endurance and strength training programs for optimal individual adaptations.

Core strength training for patients with chronic low back pain.

PubMed

Chang, Wen-Dien; Lin, Hung-Yu; Lai, Ping-Tung

2015-03-01

[Purpose] Through core strength training, patients with chronic low back pain can strengthen their deep trunk muscles. However, independent training remains challenging, despite the existence of numerous core strength training strategies. Currently, no standardized system has been established analyzing and comparing the results of core strength training and typical resistance training. Therefore, we conducted a systematic review of the results of previous studies to explore the effectiveness of various core strength training strategies for patients with chronic low back pain. [Methods] We searched for relevant studies using electronic databases. Subsequently, we evaluated their quality by analyzing the reported data. [Results] We compared four methods of evaluating core strength training: trunk balance, stabilization, segmental stabilization, and motor control exercises. According to the results of various scales and evaluation instruments, core strength training is more effective than typical resistance training for alleviating chronic low back pain. [Conclusion] All of the core strength training strategies examined in this study assist in the alleviation of chronic low back pain; however, we recommend focusing on training the deep trunk muscles to alleviate chronic low back pain.

Inspiratory muscle training in patients with chronic obstructive pulmonary disease: structural adaptation and physiologic outcomes.

PubMed

Ramirez-Sarmiento, Alba; Orozco-Levi, Mauricio; Guell, Rosa; Barreiro, Esther; Hernandez, Nuria; Mota, Susana; Sangenis, Merce; Broquetas, Joan M; Casan, Pere; Gea, Joaquim

2002-12-01

The present study was aimed at evaluating the effects of a specific inspiratory muscle training protocol on the structure of inspiratory muscles in patients with chronic obstructive pulmonary disease. Fourteen patients (males, FEV1, 24 +/- 7% predicted) were randomized to either inspiratory muscle or sham training groups. Supervised breathing using a threshold inspiratory device was performed 30 minutes per day, five times a week, for 5 consecutive weeks. The inspiratory training group was subjected to inspiratory loading equivalent to 40 to 50% of their maximal inspiratory pressure. Biopsies from external intercostal muscles and vastus lateralis (control muscle) were taken before and after the training period. Muscle samples were processed for morphometric analyses using monoclonal antibodies against myosin heavy chain isoforms I and II. Increases in both the strength and endurance of the inspiratory muscles were observed in the inspiratory training group. This improvement was associated with increases in the proportion of type I fibers (by approximately 38%, p < 0.05) and in the size of type II fibers (by approximately 21%, p < 0.05) in the external intercostal muscles. No changes were observed in the control muscle. The study demonstrates that inspiratory training induces a specific functional improvement of the inspiratory muscles and adaptive changes in the structure of external intercostal muscles.

The Effect of Concentric Isokinetic Strength Training of the Quadriceps Femoris on Electromyography and Muscle Strength in the Trained and Untrained Limb.

ERIC Educational Resources Information Center

Evetovich, Tammy K.; Housh, Terry J.; Housh, Dona J.; Johnson, Glen O.; Smith, Douglas B.; Ebersole, Kyle T.

2001-01-01

Examined the effects of unilateral concentric isokinetic leg extension training on peak torque and electromyographic (EMG) responses in trained and untrained limbs. Adult men participated in training and control groups. Overall, unilateral concentric isokinetic strength training induced strength increases in trained as well as untrained limbs.…

Muscular adaptations in low- versus high-load resistance training: A meta-analysis.

PubMed

Schoenfeld, Brad J; Wilson, Jacob M; Lowery, Ryan P; Krieger, James W

2016-01-01

There has been much debate as to optimal loading strategies for maximising the adaptive response to resistance exercise. The purpose of this paper therefore was to conduct a meta-analysis of randomised controlled trials to compare the effects of low-load (≤60% 1 repetition maximum [RM]) versus high-load (≥65% 1 RM) training in enhancing post-exercise muscular adaptations. The strength analysis comprised 251 subjects and 32 effect sizes (ESs), nested within 20 treatment groups and 9 studies. The hypertrophy analysis comprised 191 subjects and 34 ESs, nested with 17 treatment groups and 8 studies. There was a trend for strength outcomes to be greater with high loads compared to low loads (difference = 1.07 ± 0.60; CI: -0.18, 2.32; p = 0.09). The mean ES for low loads was 1.23 ± 0.43 (CI: 0.32, 2.13). The mean ES for high loads was 2.30 ± 0.43 (CI: 1.41, 3.19). There was a trend for hypertrophy outcomes to be greater with high loads compared to low loads (difference = 0.43 ± 0.24; CI: -0.05, 0.92; p = 0.076). The mean ES for low loads was 0.39 ± 0.17 (CI: 0.05, 0.73). The mean ES for high loads was 0.82 ± 0.17 (CI: 0.49, 1.16). In conclusion, training with loads ≤50% 1 RM was found to promote substantial increases in muscle strength and hypertrophy in untrained individuals, but a trend was noted for superiority of heavy loading with respect to these outcome measures with null findings likely attributed to a relatively small number of studies on the topic.

Improved heart rate recovery despite reduced exercise performance following heavy training: A within-subject analysis.

PubMed

Thomson, Rebecca L; Bellenger, Clint R; Howe, Peter R C; Karavirta, Laura; Buckley, Jonathan D

2016-03-01

The recovery of heart rate (HRR) after exercise is a potential indicator of fitness which has been shown to respond to changes in training. This study investigated the within-individual association between HRR and exercise performance following three different training loads. 11 male cyclists/triathletes were tested after two weeks of light training, two weeks of heavy training and two days of rest. Exercise performance was measured using a 5-min maximal cycling time-trial. HRR was measured over 60s during supine recovery. Exercise performance decreased 2.2±2.5% following heavy training compared with post-light training (p=0.01), and then increased 4.0±4.2% following rest (p=0.004). Most HRR indices indicated a more rapid recovery of heart rate (HR) following heavy training, and reverted to post light training levels following two days of rest. HRR indices did not differ between post-light training and after the rest period (p>0.6). There were inverse within-subject relationships between indices of HRR and performance (r=-0.6, p≤0.004). Peak HR decreased 3.2±5.1bpm following heavy training (p=0.06) and significantly increased 4.9±4.3bpm following recovery (p=0.004). There was a moderate within-subject relationship between peak HR and exercise performance (r=0.7, p≤0.001). Controlling for peak HR reduced the relationships between HRR and performance (r=-0.4-0.5, p<0.05). This study demonstrated that HRR tracks short-term changes in exercise performance within-individuals, such that increases in HRR are associated with poorer exercise performance following heavy training. Peak HR can be compromised under conditions of fatigue, and needs to be taken into account in HRR analyses. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Single- vs. Multiple-Set Strength Training in Women.

ERIC Educational Resources Information Center

Schlumberger, Andreas; Stec, Justyna; Schmidtbleicher, Dietmar

2001-01-01

Compared the effects of single- and multiple-set strength training in women with basic experience in resistance training. Both training groups had significant strength improvements in leg extension. In the seated bench press, only the three-set group showed a significant increase in maximal strength. There were higher strength gains overall in the…

Resistance Training for Muscle Weakness in Multiple Sclerosis: Direct Versus Contralateral Approach in Individuals With Ankle Dorsiflexors' Disparity in Strength.

PubMed

Manca, Andrea; Cabboi, Maria Paola; Dragone, Daniele; Ginatempo, Francesca; Ortu, Enzo; De Natale, Edoardo Rosario; Mercante, Beniamina; Mureddu, Giovanni; Bua, Guido; Deriu, Franca

2017-07-01

To compare effects of contralateral strength training (CST) and direct strength training of the more affected ankle dorsiflexors on muscle performance and clinical functional outcomes in people with multiple sclerosis (MS) exhibiting interlimb strength asymmetry. Randomized controlled trial. University hospital. Individuals with relapsing-remitting MS (N=30) and mild-to-moderate disability (Expanded Disability Status Scale score ≤6) presenting with ankle dorsiflexors' strength disparity. Participants were randomly assigned to a CST (n=15) or direct strength training (n=15) group performing 6 weeks of maximal intensity strength training of the less or more affected dorsiflexors, respectively. Maximal strength, endurance to fatigue, and mobility outcomes were assessed before, at the intervention end, and at 12-week follow-up. Strength and fatigue parameters were measured after 3 weeks of training (midintervention). In the more affected limb of both groups, pre- to postintervention significant increases in maximal strength (P≤.006) and fatigue endurance (P≤.04) were detected along with consistent retention of these improvements at follow-up (P≤.04). At midintervention, the direct strength training group showed significant improvements (P≤.002), with no further increase at postintervention, despite training continuation. Conversely, the CST group showed nonsignificant strength gains, increasing to significance at postintervention (P≤.003). In both groups, significant pre- to postintervention improvements in mobility outcomes (P≤.03), not retained at follow-up, were observed. After 6 weeks of training, CST proved as effective as direct strength training in enhancing performance of the more affected limb with a different time course, which may have practical implications in management of severely weakened limbs where direct strength training is not initially possible. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.

Influence of running velocity on vertical, leg and joint stiffness : modelling and recommendations for future research.

PubMed

Brughelli, Matt; Cronin, John

2008-01-01

Human running can be modelled as either a spring-mass model or multiple springs in series. A force is required to stretch or compress the spring, and thus stiffness, the variable of interest in this paper, can be calculated from the ratio of this force to the change in spring length. Given the link between force and length change, muscle stiffness and mechanical stiffness have been areas of interest to researchers, clinicians, and strength and conditioning practitioners for many years. This review focuses on mechanical stiffness, and in particular, vertical, leg and joint stiffness, since these are the only stiffness types that have been directly calculated during human running. It has been established that as running velocity increases from slow-to-moderate values, leg stiffness remains constant while both vertical stiffness and joint stiffness increase. However, no studies have calculated vertical, leg or joint stiffness over a range of slow-to-moderate values to maximum values in an athletic population. Therefore, the effects of faster running velocities on stiffness are relatively unexplored. Furthermore, no experimental research has examined the effects of training on vertical, leg or joint stiffness and the subsequent effects on running performance. Various methods of training (Olympic style weightlifting, heavy resistance training, plyometrics, eccentric strength training) have shown to be effective at improving running performance. However, the effects of these training methods on vertical, leg and joint stiffness are unknown. As a result, the true importance of stiffness to running performance remains unexplored, and the best practice for changing stiffness to optimize running performance is speculative at best. It is our hope that a better understanding of stiffness, and the influence of running speed on stiffness, will lead to greater interest and an increase in experimental research in this area.

Spine lateral flexion strength development differences between exercises with pelvic stabilization and without pelvic stabilization

NASA Astrophysics Data System (ADS)

Straton, Alexandru; Gidu, Diana Victoria; Micu, Alexandru

2015-02-01

Poor lateral flexor muscle strength can be an important source of lumbar/thoracic back pain in women. The purpose of this study was to evaluate pelvic stabilization (PS) and no pelvic stabilization (NoPS) lateral flexion strength exercise training on the development of isolated right and left lateral flexion strength. Isometric torque of the isolated right and left lateral flexion muscles was measured at two positions (0° and 30° opposed angle range of motion) on 42 healthy women before and after 8 weeks of PS and NoPS lateral flexion strength exercise training. Subjects were assigned in three groups, the first (n=14) trained 3 times/week with PS lateral flexion strength exercise, the second (n=14) trained 3 times/week with NoPS lateral flexion strength exercise and the third (control, n=14) did not train. Post training isometric strength values describing PS and NoPS lateral flexion strength improved in greater extent for the PS lateral flexion strength exercise group and in lesser extent for the NoPS lateral flexion strength exercise group, in both angles (p<0.05) relative to controls. These data indicate that the most effective way of training the spine lateral flexion muscles is PS lateral flexion strength exercises; NoPS lateral flexion strength exercises can be an effective way of training for the spine lateral flexion muscles, if there is no access to PS lateral flexion strength training machines.

Strength Training in Children and Adolescents

PubMed Central

Dahab, Katherine Stabenow; McCambridge, Teri Metcalf

2009-01-01

Context: Strength training in children, in combination with plyometric and/or agility training, has become an increasingly popular tactic for athletes to gain a competitive edge during the off-season. The present review clarifies some common myths associated with strength training in children, and it outlines the most current recommendations. Evidence Acquisition: Relevant studies on strength training in children and adolescents were reviewed (search results included studies indexed in PubMed and MEDLINE from 1980 through 2008). Also reviewed were recommendations from consensus guidelines and position statements applicable to strength training in youth. Results: Children can improve strength by 30% to 50% after just 8 to 12 weeks of a well-designed strength training program. Youth need to continue to train at least 2 times per week to maintain strength. The case reports of injuries related to strength training, including epiphyseal plate fractures and lower back injuries, are primarily attributed to the misuse of equipment, inappropriate weight, improper technique, or lack of qualified adult supervision. Conclusion: Youth—athletes and nonathletes alike—can successfully and safely improve their strength and overall health by participating in a well-supervised program. Trained fitness professionals play an essential role in ensuring proper technique, form, progression of exercises, and safety in this age group. PMID:23015875

At-home resistance tubing strength training increases shoulder strength in the trained and untrained limb.

PubMed

Magnus, C R A; Boychuk, K; Kim, S Y; Farthing, J P

2014-06-01

The purpose was to determine if an at-home resistance tubing strength training program on one shoulder (that is commonly used in rehabilitation settings) would produce increases in strength in the trained and untrained shoulders via cross-education. Twenty-three participants were randomized to TRAIN (strength-trained one shoulder; n = 13) or CONTROL (no intervention; n = 10). Strength training was completed at home using resistance tubing and consisted of maximal shoulder external rotation, internal rotation, scaption, retraction, and flexion 3 days/week for 4 weeks. Strength was measured via handheld dynamometry and muscle size measured via ultrasound. For external rotation strength, the trained (10.9 ± 10.9%) and untrained (12.7 ± 9.6%) arm of TRAIN was significantly different than CONTROL (1.6 ± 13.2%; -2.7 ± 12.3%; pooled across arm; P < 0.05). For internal rotation strength, the trained (14.8 ± 11.3%) and untrained (14.6 ± 10.1%) arm of TRAIN was significantly different than CONTROL (6.4 ± 11.2%; 5.1 ± 8.8%; pooled across arm; P < 0.05). There were no significant differences for scaption strength (P = 0.056). TRAIN significantly increased muscle size in the training arm of the supraspinatus (1.90 ± 0.32 to 1.99 ± 0.31 cm), and the anterior deltoid (1.08 ± 0.37 to 1.21 ± 0.39 cm; P < 0.05). This study suggests that an at-home resistance tubing training program on one limb can produce increases in strength in both limbs, and has implications for rehabilitation after unilateral shoulder injuries. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

New LUX result constrains exotic quark mediators with the vector dark matter

NASA Astrophysics Data System (ADS)

Chen, Chuan-Ren; Li, Ming-Jie

2016-12-01

The scenario of the compressed mass spectrum between heavy quark and dark matter is a challenge for LHC searches. However, the elastic scattering cross-section between dark matter and nuclei in dark matter direct detection experiments can be enhanced with nearly degenerate masses between heavy quarks and dark matter. In this paper, we illustrate such scenario with a vector dark matter, using the latest result from LUX 2016. The mass constraints on heavy quarks can be more stringent than current limits from LHC, unless the coupling strength is very small. However, the compress mass spectrum with allowed tiny coupling strength makes the decay lifetime of heavy quarks longer than the timescale of QCD hadronization.

The corticospinal responses of metronome-paced, but not self-paced strength training are similar to motor skill training.

PubMed

Leung, Michael; Rantalainen, Timo; Teo, Wei-Peng; Kidgell, Dawson

2017-12-01

The corticospinal responses to skill training may be different to strength training, depending on how the strength training is performed. It was hypothesised that the corticospinal responses would not be different following skill training and metronome-paced strength training (MPST), but would differ when compared with self-paced strength training (SPST). Corticospinal excitability, short-interval intra-cortical inhibition (SICI) and strength and tracking error were measured at baseline and 2 and 4 weeks. Participants (n = 44) were randomly allocated to visuomotor tracking, MPST, SPST or a control group. MPST increased strength by 7 and 18%, whilst SPST increased strength by 12 and 26% following 2 and 4 weeks of strength training. There were no changes in strength following skill training. Skill training reduced tracking error by 47 and 58% at 2 and 4 weeks. There were no changes in tracking error following SPST; however, tracking error reduced by 24% following 4 weeks of MPST. Corticospinal excitability increased by 40% following MPST and by 29% following skill training. There was no change in corticospinal excitability following 4 weeks of SPST. Importantly, the magnitude of change between skill training and MPST was not different. SICI decreased by 41 and 61% following 2 and 4 weeks of MPST, whilst SICI decreased by 41 and 33% following 2 and 4 weeks of skill training. Again, SPST had no effect on SICI at 2 and 4 weeks. There was no difference in the magnitude of SICI reduction between skill training and MPST. This study adds new knowledge regarding the corticospinal responses to skill and MPST, showing they are similar but different when compared with SPST.

MSW fly ash stabilized with coal ash for geotechnical application.

PubMed

Kamon, M; Katsumi, T; Sano, Y

2000-09-15

The solidification and stabilization of municipal solid waste (MSW) fly ash for the purpose of minimizing the geo-environmental impact caused by toxic heavy metals as well as ensuring engineering safety (strength and soaking durability) are experimentally evaluated. The mixtures of MSW fly ash stabilized with cement and fluidized bed combustion coal fly ash (FCA) were used for unconfined compressive strength tests, leachate tests, and soaking tests. The behavior of soluble salts contained in the MSW fly ash significantly affects strength development, soaking durability, and the hardening reaction of the stabilized MSW fly ash mixtures. The cement stabilization of the MSW fly ash does not have enough effect on strength development and soaking durability. The addition of cement only contributes to the containment of heavy metals due to the high level of alkalinity. When using FCA as a stabilizing agent for MSW fly ash, the mixture exhibits high strength and durability. However, the Cd leachate cannot be prevented in the early stages of curing. Using a combination of cement and FCA as a MSW fly ash stabilizer can attain high strength, high soaking durability, and the containment of heavy metals. The stabilized MSW fly ash with cement and FCA can be practically applied to embankments.

Strength Training and Children's Health.

ERIC Educational Resources Information Center

Faigenbaum, Avery D.

2001-01-01

Provides an overview of the potential health benefits of strength training for children, discussing the role of strength training in preventing sports-related injuries and highlighting design considerations for such programs. The focus is on musculoskeletal adaptations to strength training that are observable in healthy children. Guidelines for…

What Are Strength Training Activities?

Cancer.gov

Strength training is any practice or exercise specifically designed to increase muscle tone, strength, and fitness. Concerned that strength training will make you bulky and too muscle-y? You are not alone.

The effect of heavy- vs. light-load jump squats on the development of strength, power, and speed.

PubMed

McBride, Jeffrey M; Triplett-McBride, Travis; Davie, Allan; Newton, Robert U

2002-02-01

The purpose of this investigation was to examine the effect of an 8-week training program with heavy- vs. light-load jump squats on various physical performance measures and electromyography (EMG). Twenty-six athletic men with varying levels of resistance training experience performed sessions of jump squats with either 30% (JS30, n = 9) or 80% (JS80, n = 10) of their one repetition maximum in the squat (1RM) or served as a control (C, n = 7). An agility test, 20-m sprint, and jump squats with 30% (30J), 55% (55J), and 80% (80J) of their 1RM were performed before and after training. Peak force, peak velocity (PV), peak power (PP), jump height, and average EMG (concentric phase) were calculated for the jumps. There were significant increases in PP and PV in the 30J, 55J, and 80J for the JS30 group (p

Initial Effects of Heavy Vehicle Trafficking on Vegetated Soils

DTIC Science & Technology

2012-08-01

ER D C/ CR R EL T R -1 2 -6 Optimal Allocation of Land for Training and Non-training Uses ( OPAL ) Initial Effects of Heavy Vehicle...the outdoor loam test section. Optimal Allocation of Land for Training and Non-training Uses ( OPAL ) ERDC/CRREL TR-12-6 August 2012 Initial...mal Allocation of Land for Training and Non-Training Uses ( OPAL ) Pro- gram. The work was conducted by Nicole Buck and Sally Shoop of the Force

HEAVY MANUAL WORK THROUGHOUT THE WORKING LIFETIME AND MUSCLE STRENGTH AMONG MEN AT RETIREMENT AGE

PubMed Central

Walker-Bone, K; D’Angelo, S; Syddall, HE; Palmer, KT; Cooper, C; Coggon, D; Sayer, AA

2016-01-01

Introduction Reductions in heavy manual work as a consequence of mechanisation might impact adversely on muscle strength at older ages. We investigated the association between grip strength at retirement age and lifetime occupational exposure to physically demanding activities. Grip strength is an important predictor of long-term health and physical function in older people. Methods Grip strength (maximum of three readings in each hand) was measured in men from the Hertfordshire Cohort Study at a single examination when their mean age was 65.8 (SD 2.9) years. Associations with lifetime occupational exposure (ascertained by questionnaire) to three activities (standing/walking ≥4 hours/day; lifting ≥25 kg; and energetic work sufficient to induce sweating) were assessed by multivariable linear regression with adjustment for various potential confounders. Results Complete data were available from 1,418 men who had worked for at least 20 years. After adjustment for age, height and weight, those with longer exposures to walking/standing and heavy lifting had lower grip strength, but the relationship disappeared after further adjustment for confounders. Working at physical intensity sufficient to induce sweating was not significantly associated with grip strength. Conclusions We found no evidence that physically demanding occupational activities increase hand grip strength at normal retirement age. Any advantages of regular physical occupational activity may have been obscured by unmeasured socio-economic confounders. PMID:26896253

Effect of Movement Velocity During Resistance Training on Dynamic Muscular Strength: A Systematic Review and Meta-Analysis.

PubMed

Davies, Timothy B; Kuang, Kenny; Orr, Rhonda; Halaki, Mark; Hackett, Daniel

2017-08-01

Movement velocity is an acute resistance-training variable that can be manipulated to potentially optimize dynamic muscular strength development. However, it is unclear whether performing faster or slower repetitions actually influences dynamic muscular strength gains. We conducted a systematic review and meta-analysis to examine the effect of movement velocity during resistance training on dynamic muscular strength. Five electronic databases were searched using terms related to movement velocity and resistance training. Studies were deemed eligible for inclusion if they met the following criteria: randomized and non-randomized comparative studies; published in English; included healthy adults; used isotonic resistance-exercise interventions directly comparing fast or explosive training to slower movement velocity training; matched in prescribed intensity and volume; duration ≥4 weeks; and measured dynamic muscular strength changes. A total of 15 studies were identified that investigated movement velocity in accordance with the criteria outlined. Fast and moderate-slow resistance training were found to produce similar increases in dynamic muscular strength when all studies were included. However, when intensity was accounted for, there was a trend for a small effect favoring fast compared with moderate-slow training when moderate intensities, defined as 60-79% one repetition maximum, were used (effect size 0.31; p = 0.06). Strength gains between conditions were not influenced by training status and age. Overall, the results suggest that fast and moderate-slow resistance training improve dynamic muscular strength similarly in individuals within a wide range of training statuses and ages. Resistance training performed at fast movement velocities using moderate intensities showed a trend for superior muscular strength gains as compared to moderate-slow resistance training. Both training practices should be considered for novice to advanced, young and older resistance trainers targeting dynamic muscular strength.

How prepared are college freshmen athletes for the rigors of college strength and conditioning? A survey of college strength and conditioning coaches.

PubMed

Wade, Susan M; Pope, Zachary C; Simonson, Shawn R

2014-10-01

Training programs for high school athletes have changed over the last 20 years. High school physical education classes have transformed into sport-specific conditioning classes with intensities matching college or professional athlete programming. In addition, involvement in private, sport-specific, training increased; but despite these advanced training methods, are high school athletes prepared for collegiate sport competition? An anonymous survey was sent to 195 Division I strength and conditioning coaches (SCC) to discern incoming college freshman athletes' physical and psychological preparedness for the rigors of collegiate training and sport competition. Fifty-seven (29%) responses were received. Strength and conditioning coaches stated that incoming college freshman athletes lack lower extremity strength, overall flexibility, and core strength as well as proper Olympic lifting technique. Strength and conditioning coaches also stated that athletes lacked the mental toughness to endure collegiate sport training in addition to claiming incoming athletes lacked knowledge of correct nutrition and recovery principles. These results suggest a lack of collegiate training/sport preparedness of high school athletes. High school strength and conditioning specialist's goal is to produce better athletes and doing so requires the strength and conditioning coach/trainer to have knowledge of how to train high school athletes. One way to assure adequate knowledge of strength and conditioning training principles is for high school coaches/trainers to be certified in the field. Strength and conditioning certifications among high school strength and conditioning coaches/trainers would encourage developmentally appropriate training and would provide universities with athletes who are prepared for the rigors of collegiate sport training/competition.

Strength and balance training for adults with peripheral neuropathy and high risk of fall: current evidence and implications for future research.

PubMed

Tofthagen, Cindy; Visovsky, Constance; Berry, Donna L

2012-09-01

To evaluate the evidence for strength- and balance-training programs in patients at high risk for falls, discuss how results of existing studies might guide clinical practice, and discuss directions for additional research. A search of PubMed and CINAHL® databases was conducted in June 2011 using the terms strength, balance training, falls, elderly, and neuropathy. Only clinical trials conducted using specific strength- or balance-training exercises that included community-dwelling adults and examined falls, fall risk, balance, and/or strength as outcome measures were included in this review. One matched case-control study and two randomized, controlled studies evaluating strength and balance training in patients with diabetes-related peripheral neuropathy were identified. Eleven studies evaluating strength and balance programs in community-dwelling adults at high risk for falls were identified. The findings from the reviewed studies provide substantial evidence to support the use of strength and balance training for older adults at risk for falls, and detail early evidence to support strength and balance training for individuals with peripheral neuropathy. The evidence demonstrates that strength and balance training is safe and effective at reducing falls and improving lower extremity strength and balance in adults aged 50 years and older at high risk for falls, including patients with diabetic peripheral neuropathy. Future studies should evaluate the effects of strength and balance training in patients with cancer, particularly individuals with chemotherapy-induced peripheral neuropathy.

A training programme to improve hip strength in persons with lower limb amputation.

PubMed

Nolan, Lee

2012-03-01

To investigate the effect of a 10-week training programme on persons with a lower limb amputation and to determine if this training is sufficient to enable running. Seven transtibial, 8 transfemoral and 1 bilateral amputee (all resulting from trauma, tumour or congenital) were randomly assigned to a training (n  =8) or control group (n = 8). Isokinetic hip flexor and extensor strength at 60 and 120º/s and oxygen consumption while walking at 1.0 m/s were tested pre- and post- a 10-week period. The training group followed a twice weekly hip strengthening programme, while the control group continued with their usual activities. Running ability was determined pre-testing, and attempted after post-testing for the training group only. The training group increased hip strength and decreased oxygen consumption. Six amputees who were previously unable to run were able to after training. The control group decreased intact limb hip extensor strength. The training programme is sufficient to improve hip strength and enable running in persons with a lower limb amputation. As hip strength was reduced in those not following the training programme, it is recommended that strength training be undertaken regularly in order to avoid losing limb strength following amputation.

Physiological Readiness and Resilience: Pillars of Military Preparedness.

PubMed

Szivak, Tunde K; Kraemer, William J

2015-11-01

Warfighters require a range of physical capabilities to meet the demands of the military profession, and physical training must address performance along an entire continuum, depending on individual needs and mission requirements. Strength and power capabilities are needed for optimal performance of anaerobic tasks such as heavy load carriage, sprinting under load, and maneuvering over uneven terrain. For optimal performance, soldiers must also be able to recover from mission demands and strenuous training. The demands placed on a soldier can result in a chronic stress, leading to decreased mission performance, increased injury risk, and increased susceptibility to illness. These factors are exacerbated by inappropriate training strategies such as overemphasis on endurance exercise combined with other stressors such as lack of sleep or inadequate nutrition. Chronic stress has been linked to overreaching/overtraining and to the development of comorbidities such as metabolic syndrome, insulin resistance, and hypertension and has adverse effects on memory and cognitive function. Resistance exercise is an effective method to improve warfighter physical performance and resilience to stress, thereby impacting mission readiness. Resistance exercise in particular confers many benefits to include increased strength and power, improved body composition, and protective effects on tendons, ligaments, and bone. Physically fit individuals not only benefit from improved mission performance but also are more resilient to operational stressors faced during combat. Ultimately, resilient soldiers are better able to cope with the physical and mental demands of the military profession and over the long term will perform better while maintaining health and well-being.

Effect of aerobic vs combined aerobic-strength training on 1-year, post-cardiac rehabilitation outcomes in women after a cardiac event.

PubMed

Arthur, Heather M; Gunn, Elizabeth; Thorpe, Kevin E; Ginis, Kathleen Martin; Mataseje, Lin; McCartney, Neil; McKelvie, Robert S

2007-11-01

To compare the effect and sustainability of 6 months combined aerobic/strength training vs aerobic training alone on quality of life in women after coronary artery by-pass graft surgery or myocardial infarction. Prospective, 2-group, randomized controlled trial. Ninety-two women who were 8-10 weeks post-coronary artery by-pass graft surgery or myocardial infarction, able to attend supervised exercise, and fluent in English. The aerobic training alone group had supervised exercise twice a week for 6 months. The aerobic/strength training group received aerobic training plus upper and lower body resistance exercises. The amount of active exercise time was matched between groups. The primary outcome, quality of life, was measured by the MOS SF-36; secondary outcomes were self-efficacy, strength and exercise capacity. After 6 months of supervised exercise training both groups showed statistically significant improvements in physical quality of life (p = 0.0002), peak VO2 (19% in aerobic/strength training vs 22% in aerobic training alone), strength (p < 0.0001) and self-efficacy for stair climbing (p = 0.0024), lifting (p < 0.0001) and walking (p = 0.0012). However, by 1-year follow-up there was a statistically significant difference in physical quality of life in favor of the aerobic/strength training group (p = 0.05). Women with coronary artery disease stand to benefit from both aerobic training alone and aerobic/strength training. However, continued improvement in physical quality of life may be achieved through combined strength and aerobic training.

Is exercise used as medicine? Association of meeting strength training guidelines and functional limitations among older US adults.

PubMed

Kraschnewski, Jennifer L; Sciamanna, Christopher N; Ciccolo, Joseph T; Rovniak, Liza S; Lehman, Erik B; Candotti, Carolina; Ballentine, Noel H

2014-09-01

To determine the association between meeting strength training guidelines (≥2 times per week) and the presence of functional limitations among older adults. This cross-sectional study used data from older adult participants (N=6763) of the National Health Interview Survey conducted in 2011 in the United States. Overall, 16.1% of older adults reported meeting strength training guidelines. For each of nine functional limitations, those with the limitation were less likely to meet strength training recommendations than those without the limitation. For example, 20.0% of those who reported no difficulty walking one-quarter mile met strength training guidelines, versus only 10.1% of those who reported difficulty (p<.001). In sum, 21.7% of those with no limitations (33.7% of sample) met strength training guidelines, versus only 15.9% of those reporting 1-4 limitations (38.5% of sample) and 9.8% of those reporting 5-9 limitations (27.8% of sample) (p<.001). Strength training is uncommon among older adults and even less common among those who need it the most. The potential for strength training to improve the public's health is therefore substantial, as those who have the most to gain from strength training participate the least. Copyright © 2014 Elsevier Inc. All rights reserved.

Anti-gravity training improves walking capacity and postural balance in patients with muscular dystrophy.

PubMed

Berthelsen, Martin Peter; Husu, Edith; Christensen, Sofie Bouschinger; Prahm, Kira Philipsen; Vissing, John; Jensen, Bente Rona

2014-06-01

Recent studies in patients with muscular dystrophies suggest positive effects of aerobic and strength training. These studies focused training on using bicycle ergometers and conventional strength training, which precludes more severely affected patients from participating, because of their weakness. We investigated the functional effects of combined aerobic and strength training in patients with Becker and limb-girdle muscular dystrophies with knee muscle strength levels as low as 3% of normal strength. Eight patients performed 10 weeks of aerobic and strength training on an anti-gravity treadmill, which offered weight support up to 80% of their body weight. Six minute walking distance, dynamic postural balance, and plasma creatine kinase were assessed 10 weeks prior to training, immediately before training and after 10 weeks of training. Training elicited an improvement of walking distance by 8±2% and dynamic postural balance by 13±4%, indicating an improved physical function. Plasma creatine kinase remained unchanged. These results provide evidence that a combination of aerobic and strength training during anti-gravity has the potential to safely improve functional ability in severely affected patients with Becker and limb-girdle muscular dystrophies. Copyright © 2014 Elsevier B.V. All rights reserved.

Alcohol and suicide in Russia, 1870-1894 and 1956-2005: evidence for the continuation of a harmful drinking culture across time?

PubMed

Stickley, Andrew; Jukkala, Tanya; Norström, Thor

2011-03-01

Previous research suggests that a strong relation exists between alcohol consumption and suicide in Soviet and post-Soviet Russia. This study extends this analysis across a much longer historical time frame by examining the relationship between heavy drinking and suicide in tsarist and post-World War II Russia. Using alcohol poisoning mortality data as a proxy for heavy drinking, time-series analytical modeling techniques were used to examine the strength of the alcohol-suicide relation in the provinces of European Russia in the period 1870-1894 and for Russia in 1956-2005. During 1870-1894, a decreasing trend was recorded in heavy drinking in Russia that contrasted with the sharp increase observed in this phenomenon in the post-World War II period. A rising trend in suicide was recorded in both study periods, although the increase was much greater in the latter period. The strength of the heavy drinking-suicide relation nevertheless remained unchanged across time, with a 10% increase in heavy drinking resulting in a 3.5% increase in suicide in tsarist Russia and a 3.8% increase in post-World War II Russia. Despite the innumerable societal changes that have occurred in Russia across the two study periods and the growth in the level of heavy drinking, the strength of the heavy drinking-suicide relation has remained unchanged across time. This suggests the continuation of a highly detrimental drinking culture where the heavy episodic drinking of distilled spirits (vodka) is an essential element in the alcohol-suicide association.

Improving strength and postural control in young skiers: whole-body vibration versus equivalent resistance training.

PubMed

Mahieu, Nele N; Witvrouw, Erik; Van de Voorde, Danny; Michilsens, Diny; Arbyn, Valérie; Van den Broecke, Wouter

2006-01-01

Several groups have undertaken studies to evaluate the physiologic effects of whole-body vibration (WBV). However, the value of WBV in a training program remains unknown. To investigate whether a WBV program results in a better strength and postural control performance than an equivalent exercise program performed without vibration. Randomized, controlled trial. Laboratory. Thirty-three Belgian competitive skiers (ages = 9-15 years). Subjects were assigned to either the WBV group or the equivalent resistance (ER) group for 6 weeks of training at 3 times per week. Isokinetic plantar and dorsiflexion peak torque, isokinetic knee flexion and extension peak torque, explosive strength (high box test), and postural control were assessed before and after the training period. Both training programs significantly improved isokinetic ankle and knee muscle strength and explosive strength. Moreover, the increases in explosive strength and in plantar-flexor strength at low speed were significantly higher in the WBV group than in the ER group after 6 weeks. However, neither WBV training nor ER training seemed to have an effect on postural control. A strength training program that includes WBV appears to have additive effects in young skiers compared with an equivalent program that does not include WBV. Therefore, our findings support the hypothesis that WBV training may be a beneficial supplementary training technique in strength programs for young athletes.

Development and application of super heavy gauge high-strength structural steel for high-rise buildings

NASA Astrophysics Data System (ADS)

Gu, Linhao Gu; Lu, Shiping; Liu, Chunming; Liu, Jingang; Zhang, Suyuan; Chu, Rensheng; Ma, Changwen

2017-09-01

This paper presents development of 130mm S460G1-Z35 by using low carbon Nb-Ni-Mo-V-Ti micro-alloying design and two-stage rolling, quenching and tempering process. For the super heavy gauge high-strength structural steel, the yield strength is higher than 450MPa, the tensile strength is higher than 550MPa, the elongation is greater than 20%, the low temperature(-40) impact energy value is not less than 250J, the z-direction section shrinkage is more than 65%, and the welding performance is good. The plate are successfully applied to the engineering construction of the city of dreams in Macau.

Strength Gains by Motor Imagery with Different Ratios of Physical to Mental Practice

PubMed Central

Reiser, Mathias; Büsch, Dirk; Munzert, Jörn

2011-01-01

The purpose of this training study was to determine the magnitude of strength gains following a high-intensity resistance training (i.e., improvement of neuromuscular coordination) that can be achieved by imagery of the respective muscle contraction imagined maximal isometric contraction (IMC training). Prior to the experimental intervention, subjects completed a 4-week standardized strength training program. 3 groups with different combinations of real maximum voluntary contraction (MVC) and mental (IMC) strength training (M75, M50, M25; numbers indicate percentages of mental trials) were compared to a MVC-only training group (M0) and a control condition without strength training (CO). Training sessions (altogether 12) consisted of four sets of two maximal 5-s isometric contractions with 10 s rest between sets of either MVC or IMC training. Task-specific effects of IMC training were tested in four strength exercises commonly used in practical settings (bench pressing, leg pressing, triceps extension, and calf raising). Maximum isometric voluntary contraction force (MVC) was measured before and after the experimental training intervention and again 1 week after cessation of the program. IMC groups (M25, M50, M75) showed slightly smaller increases in MVC (3.0% to 4.2%) than M0 (5.1%), but significantly stronger improvements than CO (−0.2%). Compared to further strength gains in M0 after 1 week (9.4% altogether), IMC groups showed no “delayed” improvement, but the attained training effects remained stable. It is concluded that high-intensity strength training sessions can be partly replaced by IMC training sessions without any considerable reduction of strength gains. PMID:21897826

Strength training, but not endurance training, reduces motor unit discharge rate variability.

PubMed

Vila-Chã, Carolina; Falla, Deborah

2016-02-01

This study evaluates and compares the effects of strength and endurance training on motor unit discharge rate variability and force steadiness of knee extensor muscles. Thirty sedentary healthy men (age, 26.0±3.8yrs) were randomly assigned to strength training, endurance training or a control group. Conventional endurance and strength training was performed 3days per week, over a period of 6weeks. Maximum voluntary contraction (MVC), time to task failure (at 30% MVC), coefficient of variation (CoV) of force and of the discharges rates of motor units from the vastus medialis obliquus and vastus lateralis were determined as subjects performed 20% and 30% MVC knee extension contractions before and after training. CoV of motor unit discharges rates was significantly reduced for both muscles following strength training (P<0.001), but did not change in the endurance (P=0.875) or control group (P=0.995). CoV of force was reduced after the strength training intervention only (P<0.01). Strength training, but not endurance training, reduces motor unit discharge rate variability and enhances force steadiness of the knee extensors. These results provide new insights into the neuromuscular adaptations that occur with different training methods. Copyright © 2015 Elsevier Ltd. All rights reserved.

The intensity and effects of strength training in the elderly.

PubMed

Mayer, Frank; Scharhag-Rosenberger, Friederike; Carlsohn, Anja; Cassel, Michael; Müller, Steffen; Scharhag, Jürgen

2011-05-01

The elderly need strength training more and more as they grow older to stay mobile for their everyday activities. The goal of training is to reduce the loss of muscle mass and the resulting loss of motor function. The dose-response relationship of training intensity to training effect has not yet been fully elucidated. PubMed was selectively searched for articles that appeared in the past 5 years about the effects and dose-response relationship of strength training in the elderly. Strength training in the elderly (>60 years) increases muscle strength by increasing muscle mass, and by improving the recruitment of motor units, and increasing their firing rate. Muscle mass can be increased through training at an intensity corresponding to 60% to 85% of the individual maximum voluntary strength. Improving the rate of force development requires training at a higher intensity (above 85%), in the elderly just as in younger persons. It is now recommended that healthy old people should train 3 or 4 times weekly for the best results; persons with poor performance at the outset can achieve improvement even with less frequent training. Side effects are rare. Progressive strength training in the elderly is efficient, even with higher intensities, to reduce sarcopenia, and to retain motor function.

An overview of strength training injuries: acute and chronic.

PubMed

Lavallee, Mark E; Balam, Tucker

2010-01-01

This article introduces the history of strength training, explains the many different styles of strength training, and discusses common injuries specific to each style. Strength training is broken down into five disciplines: basic strength or resistance training, bodybuilding, power lifting, style-dependant strength sports (e.g., strongman competitions, Highland games, field events such as shot put, discus, hammer throw, and javelin), and Olympic-style weightlifting. Each style has its own principal injuries, both acute and chronic, related to the individual technique. Acute injuries should be further categorized as emergent or nonemergent. Specific age-related populations (i.e., the very young and the aging athlete) carry additional considerations.

Role of Heavy Meromyosin in Heat-Induced Gelation in Low Ionic Strength Solution Containing L-Histidine.

PubMed

Hayakawa, Toru; Yoshida, Yuri; Yasui, Masanori; Ito, Toshiaki; Wakamatsu, Jun-ichi; Hattori, Akihito; Nishimura, Takanori

2015-08-01

The gelation of myosin has a very important role in meat products. We have already shown that myosin in low ionic strength solution containing L-histidine forms a transparent gel after heating. To clarify the mechanism of this unique gelation, we investigated the changes in the nature of myosin subfragments during heating in solutions with low and high ionic strengths with and without L-histidine. The hydrophobicity of myosin and heavy meromyosin (HMM) in low ionic strength solution containing L-histidine was lower than in high ionic strength solution. The SH contents of myosin and HMM in low ionic strength solution containing l-histidine did not change during the heating process, whereas in high ionic strength solution they decreased slightly. The heat-induced globular masses of HMM in low ionic strength solution containing L-histidine were smaller than those in high ionic strength solution. These findings suggested that the polymerization of HMM molecules by heating was suppressed in low ionic strength solution containing L-histidine, resulting in formation of the unique gel. © 2015 Institute of Food Technologists®

Alterations in Strength and Maximal Oxygen Uptake Consequent to Nautilus Circuit Weight Training.

ERIC Educational Resources Information Center

Messier, Stephen P.; Dill, Mary Elizabeth

1985-01-01

The study compared the effects on muscular strength and maximal oxygen uptake of a Nautilus circuit weight training program, a free weight strength training program, and a running program. Nautilus circuit weight training appears to be equally effective for a training period of short duration. (MT)

Strength Training: For Overall Fitness

MedlinePlus

... Medical Education and Research; 2016. AskMayoExpert. Strength training: Benefits. Rochester, Minn.: Mayo Foundation for Medical Education and Research; 2016. AskMayoExpert. Strength training: Strategies for ...

Strength training for athletes: does it really help sports performance?

PubMed

McGuigan, Michael R; Wright, Glenn A; Fleck, Steven J

2012-03-01

The use of strength training designed to increase underlying strength and power qualities in elite athletes in an attempt to improve athletic performance is commonplace. Although the extent to which strength and power are important to sports performance may vary depending on the activity, the associations between these qualities and performance have been well documented in the literature. The purpose of this review is to provide a brief overview of strength training research to determine if it really helps improve athletic performance. While there is a need for more research with elite athletes to investigate the relationship between strength training and athletic performance, there is sufficient evidence for strength training programs to continue to be an integral part of athletic preparation in team sports.

Creatine Supplementation Associated or Not with Strength Training upon Emotional and Cognitive Measures in Older Women: A Randomized Double-Blind Study

PubMed Central

Alves, Christiano Robles Rodrigues; Merege Filho, Carlos Alberto Abujabra; Benatti, Fabiana Braga; Brucki, Sonia; Pereira, Rosa Maria R.; de Sá Pinto, Ana Lucia; Lima, Fernanda Rodrigues; Roschel, Hamilton; Gualano, Bruno

2013-01-01

Purpose To assess the effects of creatine supplementation, associated or not with strength training, upon emotional and cognitive measures in older woman. Methods This is a 24-week, parallel-group, double-blind, randomized, placebo-controlled trial. The individuals were randomly allocated into one of the following groups (n=14 each): 1) placebo, 2) creatine supplementation, 3) placebo associated with strength training or 4) creatine supplementation associated with strength training. According to their allocation, the participants were given creatine (4 x 5 g/d for 5 days followed by 5 g/d) or placebo (dextrose at the same dosage) and were strength trained or not. Cognitive function, assessed by a comprehensive battery of tests involving memory, selective attention, and inhibitory control, and emotional measures, assessed by the Geriatric Depression Scale, were evaluated at baseline, after 12 and 24 weeks of the intervention. Muscle strength and food intake were evaluated at baseline and after 24 weeks. Results After the 24-week intervention, both training groups (ingesting creatine supplementation and placebo) had significant reductions on the Geriatric Depression Scale scores when compared with the non-trained placebo group (p = 0.001 and p = 0.01, respectively) and the non-trained creatine group (p < 0.001 for both comparison). However, no significant differences were observed between the non-trained placebo and creatine (p = 0.60) groups, or between the trained placebo and creatine groups (p = 0.83). Both trained groups, irrespective of creatine supplementation, had better muscle strength performance than the non-trained groups. Neither strength training nor creatine supplementation altered any parameter of cognitive performance. Food intake remained unchanged. Conclusion Creatine supplementation did not promote any significant change in cognitive function and emotional parameters in apparently healthy older individuals. In addition, strength training per se improved emotional state and muscle strength, but not cognition, with no additive effects of creatine supplementation. Trial Registration Clinicaltrials.gov NCT01164020 PMID:24098469

The cross education of strength and skill following unilateral strength training in the upper and lower limbs.

PubMed

Green, Lara A; Gabriel, David A

2018-04-18

Cross education is the strength gain or skill improvement transferred to the contralateral limb following unilateral training or practice. The present study examined the transfer of both strength and skill following a strength training program. Forty participants (20M, 20F) completed a 6-week unilateral training program of dominant wrist flexion or dorsiflexion. Strength, force variability, and muscle activity were assessed pre-training, post-training, and following 6-weeks of detraining (retention). Analyses of covariance compared the experimental limb (trained or untrained) to the control (dominant or non-dominant). There were no sex differences in the training response. Cross education of strength at post-training was 6% (p<0.01) in the untrained arm and 13% (p<0.01) in the untrained leg. Contralateral strength continued to increase following detraining to 15% in the arm (p<0.01) and 14% in the leg (p<0.01). There was no difference in strength gains between upper and lower limbs (p>0.05). Cross education of skill (force variability) demonstrated greater improvements in the untrained limbs compared to the control limbs during contractions performed without concurrent feedback. Significant increases in V-wave amplitude (p=0.02) and central activation (p<0.01) were highly correlated with contralateral strength gains. There was no change in agonist amplitude or motor unit firing rates in the untrained limbs (p>0.05). The neuromuscular mechanisms mirrored the force increases at post-training and retention supporting central drive adaptations of cross education. The continued strength increases at retention identified the presence of motor learning in cross education, as confirmed by force variability.

Fish-oil supplementation enhances the effects of strength training in elderly women.

PubMed

Rodacki, Cintia L N; Rodacki, André L F; Pereira, Gleber; Naliwaiko, Katya; Coelho, Isabela; Pequito, Daniele; Fernandes, Luiz Cléudio

2012-02-01

Muscle force and functional capacity generally decrease with aging in the older population, although this effect can be reversed, attenuated, or both through strength training. Fish oil (FO), which is rich in n-3 (omega-3) PUFAs, has been shown to play a role in the plasma membrane and cell function of muscles, which may enhance the benefits of training. The effect of strength training and FO supplementation on the neuromuscular system of the elderly has not been investigated. The objective was to investigate the chronic effect of FO supplementation and strength training on the neuromuscular system (muscle strength and functional capacity) of older women. Forty-five women (aged 64 ± 1.4 y) were randomly assigned to 3 groups. One group performed strength training only (ST group) for 90 d, whereas the others performed the same strength-training program and received FO supplementation (2 g/d) for 90 d (ST90 group) or for 150 d (ST150 group; supplemented 60 d before training). Muscle strength and functional capacity were assessed before and after the training period. No differences in the pretraining period were found between groups for any of the variables. The peak torque and rate of torque development for all muscles (knee flexor and extensor, plantar and dorsiflexor) increased from pre- to posttraining in all groups. However, the effect was greater in the ST90 and ST150 groups than in the ST group. The activation level and electromechanical delay of the muscles changed from pre- to posttraining only for the ST90 and ST150 groups. Chair-rising performance in the FO groups was higher than in the ST group. Strength training increased muscle strength in elderly women. The inclusion of FO supplementation caused greater improvements in muscle strength and functional capacity.

The effect of Nordic hamstring strength training on muscle architecture, stiffness, and strength.

PubMed

Seymore, Kayla D; Domire, Zachary J; DeVita, Paul; Rider, Patrick M; Kulas, Anthony S

2017-05-01

Hamstring strain injury is a frequent and serious injury in competitive and recreational sports. While Nordic hamstring (NH) eccentric strength training is an effective hamstring injury-prevention method, the protective mechanism of this exercise is not understood. Strength training increases muscle strength, but also alters muscle architecture and stiffness; all three factors may be associated with reducing muscle injuries. The purpose of this study was to examine the effects of NH eccentric strength training on hamstring muscle architecture, stiffness, and strength. Twenty healthy participants were randomly assigned to an eccentric training group or control group. Control participants performed static stretching, while experimental participants performed static stretching and NH training for 6 weeks. Pre- and post-intervention measurements included: hamstring muscle architecture and stiffness using ultrasound imaging and elastography, and maximal hamstring strength measured on a dynamometer. The experimental group, but not the control group, increased volume (131.5 vs. 145.2 cm 3 , p < 0.001) and physiological cross-sectional area (16.1 vs. 18.1 cm 2 , p = 0.032). There were no significant changes to muscle fascicle length, stiffness, or eccentric hamstring strength. The NH intervention was an effective training method for muscle hypertrophy, but, contrary to common literature findings for other modes of eccentric training, did not increase fascicle length. The data suggest that the mechanism behind NH eccentric strength training mitigating hamstring injury risk could be increasing volume rather than increasing muscle length. Future research is, therefore, warranted to determine if muscle hypertrophy induced by NH training lowers future hamstring strain injury risk.

Effects of combined endurance and strength training on muscle strength, power and hypertrophy in 40-67-year-old men.

PubMed

Karavirta, L; Häkkinen, A; Sillanpää, E; García-López, D; Kauhanen, A; Haapasaari, A; Alen, M; Pakarinen, A; Kraemer, W J; Izquierdo, M; Gorostiaga, E; Häkkinen, K

2011-06-01

Both strength and endurance training have several positive effects on aging muscle and physical performance of middle-aged and older adults, but their combination may compromise optimal adaptation. This study examined the possible interference of combined strength and endurance training on neuromuscular performance and skeletal muscle hypertrophy in previously untrained 40-67-year-old men. Maximal strength and muscle activation in the upper and lower extremities, maximal concentric power, aerobic capacity and muscle fiber size and distribution in the vastus lateralis muscle were measured before and after a 21-week training period. Ninety-six men [mean age 56 (SD 7) years] completed high-intensity strength training (S) twice a week, endurance training (E) twice a week, combined training (SE) four times per week or served as controls (C). SE and S led to similar gains in one repetition maximum strength of the lower extremities [22 (9)% and 21 (8)%, P<0.001], whereas E and C showed minor changes. Cross-sectional area of type II muscle fibers only increased in S [26 (22)%, P=0.002], while SE showed an inconsistent, non-significant change [8 (35)%, P=0.73]. Combined training may interfere with muscle hypertrophy in aging men, despite similar gains in maximal strength between the strength and the combined training groups. © 2009 John Wiley & Sons A/S.

Improvement of Ice Hockey Players' On-Ice Sprint With Combined Plyometric and Strength Training.

PubMed

Dæhlin, Torstein E; Haugen, Ole C; Haugerud, Simen; Hollan, Ivana; Raastad, Truls; Rønnestad, Bent R

2017-08-01

Combined plyometric and strength training has previously been suggested as a strategy to improve skating performance in ice hockey players. However, the effects of combined plyometric and strength training have not previously been compared with the effects of strength training only. To compare the effects of combined plyometric and strength training on ice hockey players' skating sprint performance with those of strength training only. Eighteen participants were randomly assigned to 2 groups that completed 5 strength-training sessions/wk for 8 wk. One group included plyometric exercises at the start of 3 sessions/wk (PLY+ST), and the other group included core exercises in the same sessions (ST). Tests of 10- and 35-m skating sprints, horizontal jumping, 1-repetition-maximum (1 RM) squat, skating multistage aerobic test (SMAT), maximal oxygen consumption, repeated cycle sprints, and body composition were performed before and after the intervention. The participants increased their 1RM squat, lean mass, and body mass (P < .05), with no difference between the groups. Furthermore, they improved their 3×broad jump, repeated cycle sprint, and SMAT performance (P < .05), with no difference between the groups. PLY+ST gained a larger improvement in 10-m on-ice sprint performance than ST (P < .025). Combining plyometric and strength training for 8 wk was superior to strength training alone at improving 10-m on-ice sprint performance in high-level ice hockey players.

Maximal Strength Training Improves Surfboard Sprint and Endurance Paddling Performance in Competitive and Recreational Surfers.

PubMed

Coyne, Joseph O C; Tran, Tai T; Secomb, Josh L; Lundgren, Lina E; Farley, Oliver R L; Newton, Robert U; Sheppard, Jeremy M

2017-01-01

Coyne, JOC, Tran, TT, Secomb, JL, Lundgren, LE, Farley, ORL, Newton, RU, and Sheppard, JM. Maximal strength training improves surfboard sprint and endurance paddling performance in competitive and recreational surfers. J Strength Cond Res 31(1): 244-253, 2017-Upper-body (UB) strength has very high correlations with faster surfboard paddling speeds. However, there is no research examining the effects of improving UB strength has on surfboard paddling ability. This study aimed to determine the influence that improvements in UB closed-kinetic chain maximal strength have on surfboard paddling in both competitive and recreational surfers. Seventeen competitive and recreational male surfers (29.7 ± 7.7 years, 177.4 ± 7.4 cm, 76.7 ± 9.9 kg) participated in a repeated-measures, parallel control study design. Anthropometry; 5-, 10-, and 15-m sprint; and 400-m endurance surfboard paddling tests along with pull-up and dip 1 repetition maximum strength tests were assessed pre- and postintervention. Subjects in the training group performed 5 weeks of maximal strength training in the pull-up and dip. Differences between the training and control groups were examined postintervention. The training group increased their speed over the 5-, 10-, and 15-m sprint, whereas the control group became slower (d = 0.71, 0.51, and 0.4, respectively). The training group also displayed faster endurance paddling performance compared with the control group (d = 0.72). Short-term exposure to maximal strength training elicits improvements in paddling performance measures. However, the magnitude of performance increases seems to be dependent on initial strength levels with differential responses between strong and weaker athletes. Although a longer maximal strength training period may have produced more significant paddling improvements in stronger subjects, practitioners are unlikely to have any more than 5 weeks in an uninterrupted block with competitive surfing athletes. This study reveals that a "threshold" level of maximal strength that if possessed, short-term maximal strength training may only provide little improvement in paddling performance.

Increasing Lean Mass and Strength: A Comparison of High Frequency Strength Training to Lower Frequency Strength Training.

PubMed

Thomas, Michael H; Burns, Steve P

The purpose of this study was to determine the effect strength training frequency has on improvements in lean mass and strength. Participants were 7 women and 12 men, age ( χ̄ = 34.64 years ± 6.91 years), with strength training experience, training age ( χ̄ = 51.16 months ± 39.02 months). Participants were assigned to one of two groups to equal baseline group demographics. High frequency training group (HFT) trained each muscle group as the agonist, 3 times per week, exercising with 3 sets per muscle group per session (3 total body workouts). Low frequency training group (LFT) trained each muscle group as the agonist one time per week, completing all 9 sets during that one workout. LFT consisted of a routine split over three days: 1) pectoralis, deltoids, and triceps; 2) upper back and biceps; 3) quadriceps, hamstrings, calves, and abdominals. Following eight weeks of training, HFT increased lean mass by 1.06 kg ± 1.78 kg, (1.9%), and LFT increased lean mass by .99 kg ± 1.31 kg, (2.0%). HFT strength improvements on the chest press was 9.07 kg ± 6.33 kg, (11%), and hack squat 20.16 kg ± 11.59 kg, (21%). LFT strength improvements on chest press was 5.80kg ± 4.26 kg, (7.0%), and hack squat 21.83 kg ± 11.17 kg, (24 %). No mean differences between groups were significant. These results suggest that HFT and LFT of equal set totals result in similar improvements in lean mass and strength, following 8 weeks of strength training.

Systematic review on strength training in Parkinson’s disease: an unsolved question

PubMed Central

Ramazzina, Ileana; Bernazzoli, Benedetta; Costantino, Cosimo

2017-01-01

The purpose of this study was to investigate the effectiveness of strength training, performed against a different resistance from body weight, in improving motor and nonmotor symptoms in patients with Parkinson’s disease (PD). The following electronic databases were searched: PubMed, Physiotherapy Evidence Database, Cochrane Central Register of Controlled Trials, Scopus, and Web of Science. The review was conducted and reported in accordance with the PRISMA statement. Thirteen high-quality randomized controlled trials were included. Strength training performed against external resistance is well tolerated and appears to be a suitable physical activity to improve both physical parameters and quality of life parameters of PD subjects. However, although the study intervention included strength training, only a few selected studies assessed the improvement of muscle strength. Despite the encouraging results, it is difficult to establish a correlation between strength training and the improvements made. Our review highlights the lack of common intent in terms of study design and the presence of different primary and secondary outcomes. Accordingly, further studies are needed to support the beneficial effects of different types of strength training in PD subjects and to underline the superiority of strength training in PD patients with respect to other training. PMID:28408811

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials.

PubMed

Kelley, George A; Kelley, Kristi S; Pate, Russell R

2017-05-01

Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents. Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U 3 ) were also calculated. Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19 to -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training. Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score. © 2016 Chinese Cochrane Center, West China Hospital of Sichuan University and John Wiley & Sons Australia, Ltd.

Exercise and BMI z-score in Overweight and Obese Children and Adolescents: A Systematic Review and Network Meta-Analysis of Randomized Trials

PubMed Central

George, Kelley; Kristi, Kelley; Russell, Pate

2017-01-01

Aim Examine the effects of selected types of exercise (aerobic, strength training, both) on BMI z-score in overweight and obese children and adolescents. Methods Randomized exercise intervention trials ≥ 4 weeks were included. Studies were retrieved by searching six electronic databases, cross-referencing and expert review. Dual selection and abstraction occurred. Risk of bias and confidence in cumulative evidence were assessed. Network meta-analysis was performed using multivariate random-effects meta-regression models while surface under the cumulative ranking curves were used to calculate a hierarchy of exercise treatments. The number needed to treat (NNT) and percentile improvement (U3) were also calculated. Results Thirty-four studies representing 2,239 participants were included. Median exercise occurred 3 times per week, 50 minutes per session over a 12-week period. Statistically significant reductions in BMI z-score were found for aerobic exercise and combined aerobic and strength exercise, but not strength training alone (M±SD, 95% CI: aerobic, -0.10, -0.15 to -0.05; aerobic and strength, -0.11, -0.19, -0.03; strength, 0.04, -0.07 to 0.15). Combined aerobic and strength training was ranked best, followed by aerobic exercise and strength training. The NNT was 2 for both aerobic exercise and combined aerobic exercise and strength training. Percentile improvements were 28.8% for aerobic exercise and 31.5% for combined aerobic exercise and strength training. Confidence in effect estimates was ranked as low for aerobic exercise and very low for combined aerobic and strength training as well as strength training. Conclusions Aerobic exercise and combined aerobic exercise and strength training are associated with reductions in BMI z-score. PMID:27792271

Strength training for children and adolescents.

PubMed

Faigenbaum, A D

2000-10-01

The potential benefits of youth strength training extend beyond an increase in muscular strength and may include favorable changes in selected health- and fitness-related measures. If appropriate training guidelines are followed, regular participation in a youth strength-training program has the potential to increase bone mineral density, improve motor performance skills, enhance sports performance, and better prepare our young athletes for the demands of practice and competition. Despite earlier concerns regarding the safety and efficacy of youth strength training, current public health objectives now aim to increase the number of boys and girls age 6 and older who regularly participate in physical activities that enhance and maintain muscular fitness. Parents, teachers, coaches, and healthcare providers should realize that youth strength training is a specialized method of conditioning that can offer enormous benefit but at the same time can result in serious injury if established guidelines are not followed. With qualified instruction, competent supervision, and an appropriate progression of the volume and intensity of training, children and adolescents cannot only learn advanced strength training exercises but can feel good about their performances, and have fun. Additional clinical trails involving children and adolescents are needed to further explore the acute and chronic effects of strength training on a variety of anatomical, physiological, and psychological parameters.

Heavy Duty Mechanics Apprenticeship Training, Module One. Volume II.

ERIC Educational Resources Information Center

Batchelor, Leslie A.; Abercrombie, Richard, Ed.

This training manual, the second of two volumes, comprises the final three blocks in a nine-block in-service training course for apprentices working in heavy duty mechanics. Addressed in the individual blocks included in this volume are engines, basic electricity, and winches. Each block contains a section on parts theory that gives the purpose,…

Prepubescent Strength Training. Some Considerations.

ERIC Educational Resources Information Center

Priest, Joe W.; Holshouser, Richard S.

1987-01-01

Under the careful supervision of a trained fitness professional, the benefits of prepubescent strength training (improved strength, power, muscular endurance, bone density) outweigh the risks (acute and chronic musculoskeletal injuries). (CB)

Strength Development for Young Adolescents

ERIC Educational Resources Information Center

McDaniel, Larry W.; Jackson, Allen; Gaudet, Laura

2009-01-01

Participation in strength training is important for older children or young adolescences who wish to improve fitness or participate in sports. When designing strength training programs for our youth this age group is immature anatomically, physiologically, and psychologically. For the younger or inexperienced group the strength training activities…

The Heavy Metal Subculture and Suicide.

ERIC Educational Resources Information Center

Stack, Steven; And Others

1994-01-01

Assessed relationship between heavy metal music and suicide with data on heavy metal magazine subscriptions and youth suicide in 50 states. Found that, controlling for other predictors of suicide, greater strength of metal subculture, higher youth suicide rate, suggests that music perhaps nurtures suicidal tendencies already present in subculture.…

Strength Training. Rationale for Current Guidelines for Adult Fitness Programs.

ERIC Educational Resources Information Center

Feigenbaum, Matthew S.; Pollock, Michael L.

1997-01-01

Strength training is an effective method of developing musculoskeletal strength and is often prescribed for fitness, health, and for prevention and rehabilitation of orthopedic injuries. This paper describes and presents a rationale for the population-specific strength training guidelines established by major health organizations. (SM)

A Systematic Review and Meta-Analysis of Strength Training in Individuals With Multiple Sclerosis Or Parkinson Disease

PubMed Central

Cruickshank, Travis M.; Reyes, Alvaro R.; Ziman, Melanie R.

2015-01-01

Abstract Strength training has, in recent years, been shown to be beneficial for people with Parkinson disease and multiple sclerosis. Consensus regarding its utility for these disorders nevertheless remains contentious among healthcare professionals. Greater clarity is required, especially in regards to the type and magnitude of effects as well as the response differences to strength training between individuals with Parkinson disease or multiple sclerosis. This study examines the effects, magnitude of those effects, and response differences to strength training between patients with Parkinson disease or multiple sclerosis. A comprehensive search of electronic databases including Physiotherapy Evidence Database scale, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL was conducted from inception to July 2014. English articles investigating the effect of strength training for individuals with neurodegenerative disorders were selected. Strength training trials that met the inclusion criteria were found for individuals with Parkinson disease or multiple sclerosis. Individuals with Parkinson disease or multiple sclerosis were included in the study. Strength training interventions included traditional (free weights/machine exercises) and nontraditional programs (eccentric cycling). Included articles were critically appraised using the Physiotherapy Evidence Database scale. Of the 507 articles retrieved, only 20 articles met the inclusion criteria. Of these, 14 were randomized and 6 were nonrandomized controlled articles in Parkinson disease or multiple sclerosis. Six randomized and 2 nonrandomized controlled articles originated from 3 trials and were subsequently pooled for systematic analysis. Strength training was found to significantly improve muscle strength in people with Parkinson disease (15%–83.2%) and multiple sclerosis (4.5%–36%). Significant improvements in mobility (11.4%) and disease progression were also reported in people with Parkinson disease after strength training. Furthermore, significant improvements in fatigue (8.2%), functional capacity (21.5%), quality of life (8.3%), power (17.6%), and electromyography activity (24.4%) were found in individuals with multiple sclerosis after strength training. The limitations of the study were the heterogeneity of interventions and study outcomes in Parkinson disease and multiple sclerosis trials. Strength training is useful for increasing muscle strength in Parkinson disease and to a lesser extent multiple sclerosis. PMID:25634170

A systematic review and meta-analysis of strength training in individuals with multiple sclerosis or Parkinson disease.

PubMed

Cruickshank, Travis M; Reyes, Alvaro R; Ziman, Melanie R

2015-01-01

Strength training has, in recent years, been shown to be beneficial for people with Parkinson disease and multiple sclerosis. Consensus regarding its utility for these disorders nevertheless remains contentious among healthcare professionals. Greater clarity is required, especially in regards to the type and magnitude of effects as well as the response differences to strength training between individuals with Parkinson disease or multiple sclerosis. This study examines the effects, magnitude of those effects, and response differences to strength training between patients with Parkinson disease or multiple sclerosis. A comprehensive search of electronic databases including Physiotherapy Evidence Database scale, PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and CINAHL was conducted from inception to July 2014. English articles investigating the effect of strength training for individuals with neurodegenerative disorders were selected. Strength training trials that met the inclusion criteria were found for individuals with Parkinson disease or multiple sclerosis. Individuals with Parkinson disease or multiple sclerosis were included in the study. Strength training interventions included traditional (free weights/machine exercises) and nontraditional programs (eccentric cycling). Included articles were critically appraised using the Physiotherapy Evidence Database scale. Of the 507 articles retrieved, only 20 articles met the inclusion criteria. Of these, 14 were randomized and 6 were nonrandomized controlled articles in Parkinson disease or multiple sclerosis. Six randomized and 2 nonrandomized controlled articles originated from 3 trials and were subsequently pooled for systematic analysis. Strength training was found to significantly improve muscle strength in people with Parkinson disease (15%-83.2%) and multiple sclerosis (4.5%-36%). Significant improvements in mobility (11.4%) and disease progression were also reported in people with Parkinson disease after strength training. Furthermore, significant improvements in fatigue (8.2%), functional capacity (21.5%), quality of life (8.3%), power (17.6%), and electromyography activity (24.4%) were found in individuals with multiple sclerosis after strength training. The limitations of the study were the heterogeneity of interventions and study outcomes in Parkinson disease and multiple sclerosis trials. Strength training is useful for increasing muscle strength in Parkinson disease and to a lesser extent multiple sclerosis.

Muscular coordination and strength training. Implications for injury rehabilitation.

PubMed

Rutherford, O M

1988-03-01

Strength training is commonly used in the rehabilitation of muscles atrophied as a result of injury and/or disuse. Studies on the effects of conventional leg extension training in healthy subjects have shown the changes to be very task-specific to the training manoeuvre itself. After conventional leg extension training for the quadriceps muscle the major improvement was in weightlifting ability with only small increases in isometric strength. The maximum dynamic force and power output during sprint cycling showed no improvement. These results suggest that the major benefit of this type of training is learning to coordinate the different muscle groups involved in the training movement rather than intrinsic increases in strength of the muscle group being trained. Other studies have shown changes in strength to be specific to the length and speed at which the muscle has been trained. The implication for rehabilitation is that strength training for isolated muscle groups may not be the most effective way of increasing functional ability. As the major changes are task-specific it may be better to incorporate the training into task-related practice. This would have the advantage of strengthening the muscle groups affected whilst increasing performance in those activities which are required in daily life.

Creatine supplementation with specific view to exercise/sports performance: an update

PubMed Central

2012-01-01

Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly). PMID:22817979

Scapular-Muscle Performance: Two Training Programs in Adolescent Swimmers

PubMed Central

Van de Velde, Annemie; De Mey, Kristof; Maenhout, Annelies; Calders, Patrick; Cools, Ann M.

2011-01-01

Abstract Context: Swimming requires well-balanced scapular-muscle performance. An additional strength-training program for the shoulders is pursued by swimmers, but whether these muscle-training programs need to be generic or specific for endurance or strength is unknown. Objective: To evaluate isokinetic scapular-muscle performance in a population of adolescent swimmers and to compare the results of training programs designed for strength or muscle endurance. Design: Controlled laboratory study. Setting: University human research laboratory. Patients or Other Participants: Eighteen adolescent swimmers. Intervention(s): Each participant pursued a 12-week scapular-training program designed to improve either muscle strength or muscle endurance. Main Outcome Measure(s): Bilateral peak force, fatigue index, and protraction/retraction strength ratios before and after the scapular-training program. Results: Scapular protraction/retraction ratios were slightly higher than 1 (dominant side  =  1.08, nondominant side  =  1.25, P  =  .006). Side-to-side differences in retraction strength were apparent both before and after the training program (P  =  .03 and P  = .05, respectively). After the training program, maximal protraction (P < .05) and retraction (P < .01) strength improved on the nondominant side. Peak force and fatigue index were not different between the training groups. The fatigue indexes for protraction on both sides (P < .05) and retraction on the nondominant side (P  =  .009) were higher after the training program. Conclusions: We describe the scapular-muscle characteristics of a group of adolescent swimmers. Both muscle-strength and muscle-endurance programs improved absolute muscle strength. Neither of the strength programs had a positive effect on scapular-muscle endurance. Our results may be valuable for coaches and physiotherapists when they are designing exercise programs for swimmers. PMID:21391801

The effects of a 12-week strength-training program on strength and functionality in women with fibromyalgia.

PubMed

Kingsley, J Derek; Panton, Lynn B; Toole, Tonya; Sirithienthad, Prawee; Mathis, Reed; McMillan, Victor

2005-09-01

To determine whether women with fibromyalgia benefit from strength training. Randomized controlled trial. Testing was completed at the university and training was completed at a local community wellness facility. Twenty-nine women (age range, 18-54 y) with fibromyalgia participated. Subjects were randomly assigned to a control (n=14; wait-listed for exercise) or strength (n=15) group. After the first 4 weeks, 7 (47%) women dropped from the strength group. Subjects underwent 12 weeks of training on 11 exercises, 2 times a week, performing 1 set of 8 to 12 repetitions at 40% to 60% of their maximal lifts and were progressed to 60% to 80%. Subjects were measured for strength, functionality, tender point sensitivity, and fibromyalgia impact. The strength group significantly (P< or =.05) improved upper- (strength, 39+/-11 to 42+/-12 kg; control, 38+/-13 to 38+/-12 kg) and lower- (strength, 68+/-28 to 82+/-25 kg; control, 61+/-25 to 61+/-26 kg) body strength. Upper-body functionality measured by the Continuous-Scale Physical Functional Performance test improved significantly (strength, 44+/-11 to 50+/-16U; control, 51+/-11 to 49+/-13U) after training. Tender point sensitivity and fibromyalgia impact did not change. Strength training improved strength and some functionality in women with fibromyalgia. Interventions with resistance have important implications on independence and quality of life issues for women with fibromyalgia.

Heart Rate Dynamics after Combined Strength and Endurance Training in Middle-Aged Women: Heterogeneity of Responses

PubMed Central

Goldberger, Ary L.; Tulppo, Mikko P.; Laaksonen, David E.; Nyman, Kai; Keskitalo, Marko; Häkkinen, Arja; Häkkinen, Keijo

2013-01-01

The loss of complexity in physiological systems may be a dynamical biomarker of aging and disease. In this study the effects of combined strength and endurance training compared with those of endurance training or strength training alone on heart rate (HR) complexity and traditional HR variability indices were examined in middle-aged women. 90 previously untrained female volunteers between the age of 40 and 65 years completed a 21 week progressive training period of either strength training, endurance training or their combination, or served as controls. Continuous HR time series were obtained during supine rest and submaximal steady state exercise. The complexity of HR dynamics was assessed using multiscale entropy analysis. In addition, standard time and frequency domain measures were also computed. Endurance training led to increases in HR complexity and selected time and frequency domain measures of HR variability (P<0.01) when measured during exercise. Combined strength and endurance training or strength training alone did not produce significant changes in HR dynamics. Inter-subject heterogeneity of responses was particularly noticeable in the combined training group. At supine rest, no training-induced changes in HR parameters were observed in any of the groups. The present findings emphasize the potential utility of endurance training in increasing the complex variability of HR in middle-aged women. Further studies are needed to explore the combined endurance and strength training adaptations and possible gender and age related factors, as well as other mechanisms, that may mediate the effects of different training regimens on HR dynamics. PMID:24013586

Metabolic Effects of Chronic Heavy Physical Training on Male Age Group Swimmers.

ERIC Educational Resources Information Center

Caffrey, Garret P.; And Others

This study attempts to appraise the effectiveness of chronic heavy exercise on 13 male swimmers from 10 to 17 years of age. The experimental group trained six days a week, often with more than one workout per day. During this period, the principles of interval training were employed in conjunction with high-intensity swimming. At the completion of…

Weekly Time Course of Neuro-Muscular Adaptation to Intensive Strength Training.

PubMed

Brown, Niklas; Bubeck, Dieter; Haeufle, Daniel F B; Weickenmeier, Johannes; Kuhl, Ellen; Alt, Wilfried; Schmitt, Syn

2017-01-01

Detailed description of the time course of muscular adaptation is rarely found in literature. Thus, models of muscular adaptation are difficult to validate since no detailed data of adaptation are available. In this article, as an initial step toward a detailed description and analysis of muscular adaptation, we provide a case report of 8 weeks of intense strength training with two active, male participants. Muscular adaptations were analyzed on a morphological level with MRI scans of the right quadriceps muscle and the calculation of muscle volume, on a voluntary strength level by isometric voluntary contractions with doublet stimulation (interpolated twitch technique) and on a non-voluntary level by resting twitch torques. Further, training volume and isokinetic power were closely monitored during the training phase. Data were analyzed weekly for 1 week prior to training, pre-training, 8 weeks of training and 2 weeks of detraining (no strength training). Results show a very individual adaptation to the intense strength training protocol. While training volume and isokinetic power increased linearly during the training phase, resting twitch parameters decreased for both participants after the first week of training and stayed below baseline until de-training. Voluntary activation level showed an increase in the first 4 weeks of training, while maximum voluntary contraction showed only little increase compared to baseline. Muscle volume increased for both subjects. Especially training status seemed to influence the acute reaction to intense strength training. Fatigue had a major influence on performance and could only be overcome by one participant. The results give a first detailed insight into muscular adaptation to intense strength training on various levels, providing a basis of data for a validation of muscle fatigue and adaptation models.

Dynamic simulation of train-truck collision at level crossings

NASA Astrophysics Data System (ADS)

Ling, Liang; Guan, Qinghua; Dhanasekar, Manicka; Thambiratnam, David P.

2017-01-01

Trains crashing onto heavy road vehicles stuck across rail tracks are more likely occurrences at level crossings due to ongoing increase in the registration of heavy vehicles and these long heavy vehicles getting caught in traffic after partly crossing the boom gate; these incidents lead to significant financial losses and societal costs. This paper presents an investigation of the dynamic responses of trains under frontal collision on road trucks obliquely stuck on rail tracks at level crossings. This study builds a nonlinear three-dimensional multi-body dynamic model of a passenger train colliding with an obliquely stuck road truck on a ballasted track. The model is first benchmarked against several train dynamics packages and its predictions of the dynamic response and derailment potential are shown rational. A geometry-based derailment assessment criterion is applied to evaluate the derailment behaviour of the frontal obliquely impacted trains under different conditions. Sensitivities of several key influencing parameters, such as the train impact speed, the truck mass, the friction at truck tyres, the train-truck impact angle, the contact friction at the collision zone, the wheel/rail friction and the train suspension are reported.

Strength testing and training of rowers: a review.

PubMed

Lawton, Trent W; Cronin, John B; McGuigan, Michael R

2011-05-01

In the quest to maximize average propulsive stroke impulses over 2000-m racing, testing and training of various strength parameters have been incorporated into the physical conditioning plans of rowers. Thus, the purpose of this review was 2-fold: to identify strength tests that were reliable and valid correlates (predictors) of rowing performance; and, to establish the benefits gained when strength training was integrated into the physical preparation plans of rowers. The reliability of maximal strength and power tests involving leg extension (e.g. leg pressing) and arm pulling (e.g. prone bench pull) was high (intra-class correlations 0.82-0.99), revealing that elite rowers were significantly stronger than their less competitive peers. The greater strength of elite rowers was in part attributed to the correlation between strength and greater lean body mass (r = 0.57-0.63). Dynamic lower body strength tests that determined the maximal external load for a one-repetition maximum (1RM) leg press (kg), isokinetic leg extension peak force (N) or leg press peak power (W) proved to be moderately to strongly associated with 2000-m ergometer times (r = -0.54 to -0.68; p < 0.05). Repetition tests that assess muscular or strength endurance by quantifying the number of repetitions accrued at a fixed percentage of the strength maximum (e.g. 50-70% 1RM leg press) or set absolute load (e.g. 40 kg prone bench pulls) were less reliable and more time consuming when compared with briefer maximal strength tests. Only leg press repetition tests were correlated with 2000-m ergometer times (e.g. r = -0.67; p < 0.05). However, these tests differentiate training experience and muscle morphology, in that those individuals with greater training experience and/or proportions of slow twitch fibres performed more repetitions. Muscle balance ratios derived from strength data (e.g. hamstring-quadriceps ratio <45% or knee extensor-elbow flexor ratio around 4.2 ± 0.22 to 1) appeared useful in the pathological assessment of low back pain or rib injury history associated with rowing. While strength partially explained variances in 2000-m ergometer performance, concurrent endurance training may be counterproductive to strength development over the shorter term (i.e. <12 weeks). Therefore, prioritization of strength training within the sequence of training units should be considered, particularly over the non-competition phase (e.g. 2-6 sets × 4-12 repetitions, three sessions a week). Maximal strength was sustained when infrequent (e.g. one or two sessions a week) but intense (e.g. 73-79% of maximum) strength training units were scheduled; however, it was unclear whether training adaptations should emphasize maximal strength, endurance or power in order to enhance performance during the competition phase. Additionally, specific on-water strength training practices such as towing ropes had not been reported. Further research should examine the on-water benefits associated with various strength training protocols, in the context of the training phase, weight division, experience and level of rower, if limitations to the reliability and precision of performance data (e.g. 2000-m time or rank) can be controlled. In conclusion, while positive ergometer time-trial benefits of clinical and practical significance were reported with strength training, a lack of statistical significance was noted, primarily due to an absence of quality long-term controlled experimental research designs.

Maximum Dynamic Lower-Limb Strength Was Maintained During 24-Week Reduced Training Frequency in Previously Sedentary Older Women.

PubMed

Walker, Simon; Serrano, Javier; Van Roie, Evelien

2018-04-01

Walker, S, Serrano, J, and Van Roie, E. Maximum dynamic lower-limb strength was maintained during 24-week reduced training frequency in previously sedentary older women. J Strength Cond Res 32(4): 1063-1071, 2018-There is little study into the effects of reducing strength training below the recommended twice weekly frequency, particularly in older women, despite the possibility that individuals will encounter periods of reduced training frequency. The purpose of the present study was to determine the effects of a period of reduced training frequency on maximum strength and muscle mass of the lower limbs in comparison with the recommended training frequency of twice per week. After an initial 12-week period, where all subjects trained twice per week, a reduced strength training group (RST) trained once per week, whereas another strength training group (ST) continued to train twice per week for 24 weeks. A nontraining age-matched control group (CON) was used for comparison. All subjects were tested for leg press 1-repetition maximum (1RM), electromyogram (EMG) amplitude of vastus lateralis and medialis, and quadriceps cross-sectional area (CSA) measured by panoramic ultrasound at weeks 0, 12, and 36. Both ST and RST continued to increase 1RM during the reduced training frequency period compared with control (∼8% and ∼5% vs. ∼-3%, respectively; p ≤ 0.05). Accompanying these changes were significant increases in EMG amplitude in both ST and RST (p ≤ 0.05). However, the initial gains in quadriceps CSA made from week 0 to week 12 in RST were lost when training once per week (RST ∼-5%). Therefore, reduced training frequency in this population does not adversely affect maximum strength or muscle activity but can negatively affect muscle mass, even reversing training-induced gains. Older individuals not training at least twice per week may compromise potential increases in muscle mass, important in counteracting effects of aging.

Combined strength and endurance training in competitive swimmers.

PubMed

Aspenes, Stian; Kjendlie, Per-Ludvik; Hoff, Jan; Helgerud, Jan

2009-01-01

A combined intervention of strength and endurance training is common practice in elite swimming training, but the scientific evidence is scarce. The influences between strength and endurance training have been investigated in other sports but the findings are scattered. Some state the interventions are negative to each other, some state there is no negative relationship and some find bisected and supplementary benefits from the combination when training is applied appropriately. The aim of this study was to investigate the impact of a combined intervention among competitive swimmers. 20 subjects assigned to a training intervention group (n = 11) or a control group (n = 9) from two different teams completed the study. Anthropometrical data, tethered swimming force, land strength, performance in 50m, 100m and 400m, work economy, peak oxygen uptake, stroke length and stroke rate were investigated in all subjects at pre- and post-test. A combined intervention of maximal strength and high aerobic intensity interval endurance training 2 sessions per week over 11 weeks in addition to regular training were used, while the control group continued regular practice with their respective teams. The intervention group improved land strength, tethered swimming force and 400m freestyle performance more than the control group. The improvement of the 400m was correlated with the improvement of tethered swimming force in the female part of the intervention group. No change occurred in stroke length, stroke rate, performance in 50m or 100m, swimming economy or peak oxygen uptake during swimming. Two weekly dry-land strength training sessions for 11 weeks increase tethered swimming force in competitive swimmers. This increment further improves middle distance swimming performance. 2 weekly sessions of high- intensity interval training does not improve peak oxygen uptake compared with other competitive swimmers. Key pointsTwo weekly sessions of dry land strength training improves the swimming force.Two weekly sessions of high-intensity endurance training did not cause improved endurance capacity.It may seem that dry land strength training can improve middle distance performance.

Mixed maximal and explosive strength training in recreational endurance runners.

PubMed

Taipale, Ritva S; Mikkola, Jussi; Salo, Tiina; Hokka, Laura; Vesterinen, Ville; Kraemer, William J; Nummela, Ari; Häkkinen, Keijo

2014-03-01

Supervised periodized mixed maximal and explosive strength training added to endurance training in recreational endurance runners was examined during an 8-week intervention preceded by an 8-week preparatory strength training period. Thirty-four subjects (21-45 years) were divided into experimental groups: men (M, n = 9), women (W, n = 9), and control groups: men (MC, n = 7), women (WC, n = 9). The experimental groups performed mixed maximal and explosive exercises, whereas control subjects performed circuit training with body weight. Endurance training included running at an intensity below lactate threshold. Strength, power, endurance performance characteristics, and hormones were monitored throughout the study. Significance was set at p ≤ 0.05. Increases were observed in both experimental groups that were more systematic than in the control groups in explosive strength (12 and 13% in men and women, respectively), muscle activation, maximal strength (6 and 13%), and peak running speed (14.9 ± 1.2 to 15.6 ± 1.2 and 12.9 ± 0.9 to 13.5 ± 0.8 km Ł h). The control groups showed significant improvements in maximal and explosive strength, but Speak increased only in MC. Submaximal running characteristics (blood lactate and heart rate) improved in all groups. Serum hormones fluctuated significantly in men (testosterone) and in women (thyroid stimulating hormone) but returned to baseline by the end of the study. Mixed strength training combined with endurance training may be more effective than circuit training in recreational endurance runners to benefit overall fitness that may be important for other adaptive processes and larger training loads associated with, e.g., marathon training.

Strength and Aerobic Exercises Improve Spatial Memory in Aging Rats Through Stimulating Distinct Neuroplasticity Mechanisms.

PubMed

Vilela, Thais Ceresér; Muller, Alexandre Pastoris; Damiani, Adriani Paganini; Macan, Tamires Pavei; da Silva, Sabrina; Canteiro, Paula Bortoluzzi; de Sena Casagrande, Alisson; Pedroso, Giulia Dos Santos; Nesi, Renata Tiscoski; de Andrade, Vanessa Moraes; de Pinho, Ricardo Aurino

2017-12-01

Aging is associated with impaired cognition and memory and increased susceptibility to neurodegenerative disorders. Physical exercise is neuroprotective; however, the major evidence of this effect involves studies of only aerobic training in young animals. The benefits of other exercise protocols such as strength training in aged animals remains unknown. Here, we investigated the effect of aerobic and strength training on spatial memory and hippocampal plasticity in aging rats. Aging Wistar rats performed aerobic or strength training for 50 min 3 to 4 days/week for 8 weeks. Spatial memory and neurotrophic and glutamatergic signaling in the hippocampus of aged rats were evaluated after aerobic or strength training. Both aerobic and strength training improved cognition during the performance of a spatial memory task. Remarkably, the improvement in spatial memory was accompanied by an increase in synaptic plasticity proteins within the hippocampus after exercise training, with some differences in the intracellular functions of those proteins between the two exercise protocols. Moreover, neurotrophic signaling (CREB, BDNF, and the P75 NTR receptor) increased after training for both exercise protocols, and aerobic exercise specifically increased glutamatergic proteins (NMDA receptor and PSD-95). We also observed a decrease in DNA damage after aerobic training. In contrast, strength training increased levels of PKCα and the proinflammatory factors TNF-α and IL-1β. Overall, our results show that both aerobic and strength training improved spatial memory in aging rats through inducing distinct molecular mechanisms of neuroplasticity. Our findings extend the idea that exercise protocols can be used to improve cognition during aging.

Resistance training during preadolescence. Issues and controversies.

PubMed

Blimkie, C J

1993-06-01

High intensity resistance training appears to be effective in increasing strength in preadolescents. Children make similar relative (percentage improvement), but smaller absolute, strength gains compared with adolescents and young adults in response to similar resistance training programmes. Resistance training appears to have little if any effect on muscle size, and strength gains during training have been associated with increases in levels of neuromuscular activation and changes in intrinsic contractile characteristics of muscle. Although unsubstantiated, improved motor coordination probably also contributes to the increase in strength, especially for more complex strength manoeuvres. On the basis of limited information, training-induced strength gains are lost during detraining, and the decay in strength has been associated with a reduction in neuromuscular activation. Short term resistance training appears to have no effect on somatic growth (height or weight) and body composition, and no proven positive influence on sports performance, injury rate or recovery from injury during preadolescence. Weightlifting has proved injurious to some children, especially when unsupervised and without instruction in proper weightlifting technique and load selection. In contrast, the risk of injury from prudently prescribed and closely supervised resistance training appears to be low during preadolescence. Lastly, short term resistance training appears to have no detrimental effect during preadolescence on either cardiorespiratory fitness or resting blood pressure.

Hydration and leaching characteristics of cement pastes made from electroplating sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ying-Liang; Sustainable Environment Research Center, National Cheng Kung University, No. 1, University Rd., Tainan City 70101, Taiwan; Ko, Ming-Sheng

2011-06-15

The purpose of this study was to investigate the hydration and leaching characteristics of the pastes of belite-rich cements made from electroplating sludge. The compressive strength of the pastes cured for 1, 3, 7, 28, and 90 days was determined, and the condensation of silicate anions in hydrates was examined with the {sup 29}Si nuclear magnetic resonance (NMR) technology. The leachabilities of the electroplating sludge and the hardened pastes were studied with the multiple toxicity characteristic leaching procedure (MTCLP) and the tank leaching test (NEN 7345), respectively. The results showed that the electroplating sludge continued to leach heavy metals, includingmore » nickel, copper, and zinc, and posed a serious threat to the environment. The belite-rich cement made from the electroplating sludge was abundant in hydraulic {beta}-dicalcium silicate, and it performed well with regard to compressive-strength development when properly blended with ordinary Portland cements. The blended cement containing up to 40% the belite-rich cement can still satisfy the compressive-strength requirements of ASTM standards, and the pastes cured for 90 days had comparable compressive strength to an ordinary Portland cement paste. It was also found that the later hydration reaction of the blended cements was relatively more active, and high fractions of belite-rich cement increased the chain length of silicate hydrates. In addition, by converting the sludge into belite-rich cements, the heavy metals became stable in the hardened cement pastes. This study thus indicates a viable alternative approach to dealing with heavy metal bearing wastes, and the resulting products show good compressive strength and heavy-metal stability.« less

Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union.

PubMed

Jones, Thomas W; Smith, Andrew; Macnaughton, Lindsay S; French, Duncan N

2016-12-01

Jones, TW, Smith, A, Macnaughton, LS, and French, DN. Strength and Conditioning and Concurrent Training Practices in Elite Rugby Union. J Strength Cond Res 30(12): 3354-3366, 2016-There is limited published research on strength and conditioning (S&C) practices in elite rugby union (RU). Information regarding testing batteries and programme design would provide valuable information to both applied practitioners and researchers investigating the influence of training interventions or preperformance strategies. The aim of this study was to detail the current practices of S&C coaches and sport scientists working in RU. A questionnaire was developed that comprised 7 sections: personal details, physical testing, strength and power development, concurrent training, flexibility development, unique aspects of the programme, and any further relevant information regarding prescribed training programmes. Forty-three (41 men, 2 women; age: 33.1 ± 5.3 years) of 52 (83%) coaches responded to the questionnaire. The majority of practitioners worked with international level and/or professional RU athletes. All respondents believed strength training benefits RU performance and reported that their athletes regularly performed strength training. The clean and back squat were rated the most important prescribed exercises. Forty-one (95%) respondents reported prescribing plyometric exercises and 38 (88%) indicated that periodization strategies were used. Forty-two (98%) practitioners reported conducting physical testing, with body composition being the most commonly tested phenotype. Thirty-three (77%) practitioners indicated that the potential muted strength development associated with concurrent training was considered when programming and 27 (63%) believed that strength before aerobic training was more favorable for strength development than vice versa. This research represents the only published survey to date of S&C practices in northern and southern hemisphere RU.

The effects of the therapeutic workplace and heavy alcohol use on homelessness among homeless alcohol-dependent adults.

PubMed

Carlson, Emily; Holtyn, August F; Fingerhood, Michael; Friedman-Wheeler, Dara; Leoutsakos, Jeannie-Marie S; Silverman, Kenneth

2016-11-01

A clinical trial demonstrated that a therapeutic workplace could promote alcohol abstinence in homeless, alcohol-dependent adults. This secondary-data analysis examined rates of homelessness and their relation to the therapeutic workplace intervention and alcohol use during the trial. In the trial, homeless, alcohol-dependent adults could work in a therapeutic workplace for 6 months and were randomly assigned to Unpaid Training, Paid Training, or Contingent Paid Training groups. Unpaid Training participants were not paid for working. Paid Training participants were paid for working. Contingent Paid Training participants were paid for working if they provided alcohol-negative breath samples. Rates of homelessness during the study were calculated for each participant and the three groups were compared. Mixed-effects regression models were conducted to examine the relation between alcohol use (i.e., heavy drinking, drinks per drinking day, and days of alcohol abstinence) and homelessness. Unpaid Training, Paid Training, and Contingent Paid Training participants did not differ in the percentage of study days spent homeless (31%, 28%, 17%; respectively; F(2,94)=1.732, p=0.183). However, participants with more heavy drinking days (b=0.350, p<0.001), more drinks per drinking day (b=0.267, p<0.001), and fewer days of alcohol abstinence (b=-0.285, p<0.001) spent more time homeless. Reducing heavy drinking and alcohol use may help homeless, alcohol-dependent adults transition out of homelessness. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Positive effects of 1-year football and strength training on mechanical muscle function and functional capacity in elderly men.

PubMed

Sundstrup, Emil; Jakobsen, Markus Due; Andersen, Lars Louis; Andersen, Thomas Rostgaard; Randers, Morten Bredsgaard; Helge, Jørn Wulff; Suetta, Charlotte; Schmidt, Jakob Friis; Bangsbo, Jens; Krustrup, Peter; Aagaard, Per

2016-06-01

A decline in physical capacity takes place with increasing age that negatively affects overall physical function including work ability and the ability to perform typical activities of daily living (ADL). The overall aim of the present study was to determine the neuromuscular adaptations to long-term (1 year) football and strength training in older untrained adults, and to assess the concurrent effect on functional ADL capacity. Twenty-seven healthy elderly males (68.2 ± 3.2 years) were randomly assigned to 12 months of either recreational football training (FT: n = 10), strength training (ST: n = 9) or served as inactive controls (CON: n = 8). Recreational football training consisted of small-sided training sessions whereas strength training consisted of high intensity exercises targeting the lower extremity and upper body. Maximal thigh muscle strength and rate of force development (RFD) were assessed with isokinetic dynamometry, while postural balance and vertical jumping performance were evaluated using force plate analysis. Furthermore, functional ability was evaluated by stair-ascent and chair-rising testing. A total of nine, nine and seven participants from FT, ST and CON, respectively, were included in the analysis. Both exercise regimens led to substantial gains in functional ability, evidenced by 24 and 18 % reduced stair-ascent time, and 32 and 21 % increased chair-rising performance in FT and ST, respectively (all P < 0.05). Long-term strength training led to increased concentric (14 %; P < 0.01) and isometric (23 %; P < 0.001) quadriceps and isometric hamstring strength (44 %; P < 0.0001), whereas football training mainly resulted in enhanced hamstring strength (18 %, P < 0.05) and RFD (89 %, P < 0.0001). Long-term (1 year) strength training led to increased quadriceps and hamstring strength, whereas the adaptations to football training mainly included enhanced strength and rapid force capacity of the hamstring muscles. Gains in functional ability were observed in response to both training regimens, evidenced by reduced stair-ascent time and increased chair-rising performance. Long-term football exercise and strength training both appear to be effective interventional strategies to improve factors of importance for ADL by counteracting the age-related decline in lower limb strength and functional capacity among old male adults. This could potentially be a way to improve work ability of senior workers.

Gulf War Illnesses: Understanding of Health Effects From Depleted Uranium Evolving But Safety Training Needed

DTIC Science & Technology

2000-03-01

against enemy munitions. Depleted uranium is a low- level radioactive heavy metal , and concerns have surfaced about whether exposure to it could be a...radioactive heavy metal , the potential for health effects are twofold: effects from radiation and effects from chemical toxicity. Two recent expert...depleted uranium safety training. Background Depleted uranium (DU), a low-level radioactive heavy metal , is a by- product of the process used to

Progressive resistance training increases strength after stroke but this may not carry over to activity: a systematic review.

PubMed

Dorsch, Simone; Ada, Louise; Alloggia, Daniella

2018-04-01

Does progressive resistance training improve strength and activity after stroke? Does any increase in strength carry over to activity? Systematic review of randomised trials with meta-analysis. Adults who have had a stroke. Progressive resistance training compared with no intervention or placebo. The primary outcome was change in strength. This measurement had to be of maximum voluntary force production and performed in muscles congruent with the muscles trained in the intervention. The secondary outcome was change in activity. This measurement had to be a direct measure of performance that produced continuous or ordinal data, or with scales that produced ordinal data. Eleven studies involving 370 participants were included in this systematic review. The overall effect of progressive resistance training on strength was examined by pooling change scores from six studies with a mean PEDro score of 5.8, representing medium quality. The effect size of progressive resistance training on strength was 0.98 (95% CI 0.67 to 1.29, I 2 =0%). The overall effect of progressive resistance training on activity was examined by pooling change scores from the same six studies. The effect size of progressive resistance training on activity was 0.42 (95% CI -0.08 to 0.91, I 2 =54%). After stroke, progressive resistance training has a large effect on strength compared with no intervention or placebo. There is uncertainty about whether these large increases in strength carry over to improvements in activity. PROSPERO CRD42015025401. [Dorsch S, Ada L, Alloggia D (2018) Progressive resistance training increases strength after stroke but this may not carry over to activity: a systematic review. Journal of Physiotherapy 64: 84-90]. Copyright © 2018 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Muscle hypertrophy, strength development, and serum hormones during strength training in elderly women with fibromyalgia.

PubMed

Valkeinen, H; Häkkinen, K; Pakarinen, A; Hannonen, P; Häkkinen, A; Airaksinen, O; Niemitukia, L; Kraemer, W J; Alén, M

2005-01-01

To examine the effects of strength training on maximal force, cross-sectional area (CSA), and electromyographic (EMG) activity of muscles and serum hormone concentrations in elderly females with fibromyalgia (FM). Twenty-six patients with FM were randomly assigned to a training (FMT; n = 13; mean age 60 years) or a control (FMC; n = 13; 59 years) group. FMT performed progressive strength training twice a week for 21 weeks. The measurements included maximal isometric and concentric leg extension forces, EMG activity of the vastus lateralis and medialis, CSA of the quadriceps femoris, and serum concentrations of testosterone (T), free testosterone (FT), growth hormone (GH), insulin-like growth factor-1 (IGF-1), dehydroepiandrosterone sulfate (DHEAS), and cortisol. Subjectively perceived symptoms of FM were also assessed. All patients were able to complete the training. In FMT strength training led to increases of 36% (p<0.001) and 33% (p<0.001) in maximal isometric and concentric forces, respectively. The CSA increased by 5% (p<0.001) and the EMG activity in isometric action by 47% (p<0.001) and in concentric action by 57% (p<0.001). Basal serum hormone concentrations remained unaltered during strength training. The subjective perceived symptoms showed a minor decreasing tendency (ns). No statistically significant changes occurred in any of these parameters in FMC. Progressive strength training increases strength, CSA, and voluntary activation of the trained muscles in elderly women with FM, while the measured basal serum hormone concentrations remain unaltered. Strength training benefits the overall physical fitness of the patients without adverse effects or any exacerbation of symptoms and should be included in the rehabilitation programmes of elderly patients with FM.

Lower limb strength training in children with cerebral palsy – a randomized controlled trial protocol for functional strength training based on progressive resistance exercise principles

PubMed Central

Scholtes, Vanessa A; Dallmeijer, Annet J; Rameckers, Eugene A; Verschuren, Olaf; Tempelaars, Els; Hensen, Maartje; Becher, Jules G

2008-01-01

Background Until recently, strength training in children with cerebral palsy (CP) was considered to be inappropriate, because it could lead to increased spasticity or abnormal movement patterns. However, the results of recent studies suggest that progressive strength training can lead to increased strength and improved function, but low methodological quality and incomplete reporting on the training protocols hampers adequate interpretation of the results. This paper describes the design and training protocol of a randomized controlled trial to assess the effects of a school-based progressive functional strength training program for children with CP. Methods/Results Fifty-one children with Gross Motor Function Classification Systems levels I to III, aged of 6 to 13 years, were recruited. Using stratified randomization, each child was assigned to an intervention group (strength training) or a control group (usual care). The strength training was given in groups of 4–5 children, 3 times a week, for a period of 12 weeks. Each training session focussed on four exercises out of a 5-exercise circuit. The training load was gradually increased based on the child's maximum level of strength, as determined by the 8 Repetition Maximum (8 RM). To evaluate the effectiveness of the training, all children were evaluated before, during, directly after, and 6 weeks after the intervention period. Primary outcomes in this study were gross motor function (measured with the Gross Motor Function Measure and functional muscle strength tests) and walking ability (measured with the 10-meter, the 1-minute and the timed stair test). Secondary outcomes were lower limb muscle strength (measured with a 6 RM test, isometric strength tests, and a sprint capacity test), mobility (measured with a mobility questionnaire), and sport activities (measured with the Children's Assessment of Participation and Enjoyment). Spasticity and range of motion were assessed to evaluate any adverse events. Conclusion Randomized clinical trials are considered to present the highest level of evidence. Nevertheless, it is of utmost importance to report on the design, the applied evaluation methods, and all elements of the intervention, to ensure adequate interpretation of the results and to facilitate implementation of the intervention in clinical practice if the results are positive. Trial Registration Trial Register NTR1403 PMID:18842125

Body weight-supported training in Becker and limb girdle 2I muscular dystrophy.

PubMed

Jensen, Bente R; Berthelsen, Martin P; Husu, Edith; Christensen, Sofie B; Prahm, Kira P; Vissing, John

2016-08-01

We studied the functional effects of combined strength and aerobic anti-gravity training in severely affected patients with Becker and Limb-Girdle muscular dystrophies. Eight patients performed 10-week progressive combined strength (squats, calf raises, lunges) and aerobic (walk/run, jogging in place or high knee-lift) training 3 times/week in a lower-body positive pressure environment. Closed-kinetic-chain leg muscle strength, isometric knee strength, rate of force development (RFD), and reaction time were evaluated. Baseline data indicated an intact neural activation pattern but showed compromised muscle contractile properties. Training (compliance 91%) improved functional leg muscle strength. Squat series performance increased 30%, calf raises 45%, and lunges 23%. Anti-gravity training improved closed-kinetic-chain leg muscle strength despite no changes in isometric knee extension strength and absolute RFD. The improved closed-kinetic-chain performance may relate to neural adaptation involving motor learning and/or improved muscle strength of other muscles than the weak knee extensors. Muscle Nerve 54: 239-243, 2016. © 2016 Wiley Periodicals, Inc.

Recommendations for natural bodybuilding contest preparation: resistance and cardiovascular training.

PubMed

Helms, E R; Fitschen, P J; Aragon, A A; Cronin, J; Schoenfeld, B J

2015-03-01

The anabolic effect of resistance training can mitigate muscle loss during contest preparation. In reviewing relevant literature, we recommend a periodized approach be utilized. Block and undulating models show promise. Muscle groups should be trained 2 times weekly or more, although high volume training may benefit from higher frequencies to keep volume at any one session from becoming excessive. Low to high (~3-15) repetitions can be utilized but most repetitions should occur in the 6-12 range using 70-80% of 1 repetition maximum. Roughly 40-70 reps per muscle group per session should be performed, however higher volume may be appropriate for advanced bodybuilders. Traditional rest intervals of 1-3 minutes are adequate, but longer intervals can be used. Tempo should allow muscular control of the load; 1-2 s concentric and 2-3 s eccentric tempos. Training to failure should be limited when performing heavy loads on taxing exercises, and primarily relegated to single-joint exercises and higher repetitions. A core of multi-joint exercises with some single-joint exercises to address specific muscle groups as needed should be used, emphasizing full range of motion and proper form. Cardiovascular training can be used to enhance fat loss. Interference with strength training adaptations increases concomitantly with frequency and duration of cardiovascular training. Thus, the lowest frequency and duration possible while achieving sufficient fat loss should be used. Full-body modalities or cycling may reduce interference. High intensities may as well; however, require more recovery. Fasted cardiovascular training may not have benefits over fed-state and could be detrimental.

Effects of intensity and duration of exercise on muscular responses to training of thoroughbred racehorses.

PubMed

Rivero, José-Luis L; Ruz, Antonio; Martí-Korff, Silvia; Estepa, José-Carlos; Aguilera-Tejero, Escolástico; Werkman, Jutta; Sobotta, Mathias; Lindner, Arno

2007-05-01

This study examined the effects of the intensity and duration of exercise on the nature and magnitude of training adaptations in muscle of adolescent (2-3 yr old) racehorses. Six thoroughbreds that had been pretrained for 2 mo performed six consecutive conditioning programs of varying lactate-guided intensities [velocities eliciting blood lactate concentrations of 2.5 mmol/l (v2.5) and 4 mmol/l (v4), respectively] and durations (5, 15, 25 min). Pre- and posttraining gluteus muscle biopsies were analyzed for myosin heavy chain content, fiber-type composition, fiber size, capillarization, and fiber histochemical oxidative and glycolytic capabilities. Although training adaptations were similar in nature, they varied greatly in magnitude among the different training protocols. Overall, the use of v4 as the exercise intensity for 25 min elicited the most consistent training adaptations in muscle, whereas the minimal training stimulus that evoked any significant change was identified with exercises of 15 min at v2.5. Within this range, muscular adaptations showed significant trends to be proportional to the exercise load of specific training programs. Taken together, these data suggest that muscular adaptations to training in horses occur on a continuum that is based on the exercise intensity and duration of training. The practical implications of this study are that exercises for 15 to 25 min/day at velocities between v2.5 and v4 can improve in the short term (3 wk) the muscular stamina in thoroughbreds. However, exercises of 5-15 min at v4 are necessary to enhance muscular features related to strength (hypertrophy).

Strength training and physical activity in boys: a randomized trial.

PubMed

Meinhardt, Udo; Witassek, Fabienne; Petrò, Renato; Fritz, Chris; Eiholzer, Urs

2013-12-01

In developed societies levels of daily physical activity (PA) among school-age children are decreasing. This implies risk factors for cardiovascular and metabolic diseases. Specific strategies to improve levels of PA are needed. In prepubertal boys there is evidence that strength training increases spontaneous PA outside of training. A total of 102 schoolchildren (age 10-14 years) in Switzerland were randomly assigned to physical education classes or to participate twice weekly at a guided strength training program for 19 weeks. Spontaneous PA energy expenditure (PAEE; 3axial accelerometry for 7 days), leg and arm strength, and body composition (dual energy radiograph absorptiometry) were measured at baseline, after 19 weeks of training intervention, and after 3 months of washout. There were no significant differences between the groups at baseline. In the intervention group, PAEE increased by 10% from baseline to end of training in boys (P = .02), but not in girls. Leg and arm strength were increased owing to training intervention in both boys and girls. All other variables were unchanged. Baseline PAEE was significantly negatively correlated with changes of PAEE. Targeted strength training significantly increases daily spontaneous PA behavior in boys. The less active children showed the greatest increase in spontaneous PAEE. Girls showed a similar increase in strength, but not in spontaneous PAEE. This may be explained by their earlier pubertal development. Strength training may be a promising strategy in schools to counteract decreasing levels of PA.

The Effect of Inspiratory Muscle Training on Respiratory and Limb Locomotor Muscle Deoxygenation During Exercise with Resistive Inspiratory Loading.

PubMed

Turner, L A; Tecklenburg-Lund, S L; Chapman, R; Shei, R-J; Wilhite, D P; Mickleborough, T

2016-07-01

We investigated how inspiratory muscle training impacted respiratory and locomotor muscle deoxygenation during submaximal exercise with resistive inspiratory loading. 16 male cyclists completed 6 weeks of either true (n=8) or sham (n=8) inspiratory muscle training. Pre- and post-training, subjects completed 3, 6-min experimental trials performed at ~80%  ˙VO2peak with interventions of either moderate inspiratory loading, heavy inspiratory loading, or maximal exercise imposed in the final 3 min. Locomotor and respiratory muscle oxy-, deoxy-, and total-haemoglobin and myoglobin concentration was continuously monitored using near-infrared spectroscopy. Locomotor muscle deoxygenation changes from 80%  ˙VO2peak to heavy inspiratory loading were significantly reduced pre- to post-training from 4.3±5.6 µM to 2.7±4.7 µM. Respiratory muscle deoxygenation was also significantly reduced during the heavy inspiratory loading trial (4.6±3.5 µM to 1.9±1.5 µM) post-training. There was no significant difference in oxy-, deoxy-, or total-haemoglobin and myoglobin during any of the other loading trials, from pre- to post-training, in either group. After inspiratory muscle training, highly-trained cyclists exhibited decreased locomotor and respiratory muscle deoxygenation during exercise with heavy inspiratory loading. These data suggest that inspiratory muscle training reduces oxygen extraction by the active respiratory and limb muscles, which may reflect changes in respiratory and locomotor muscle oxygen delivery. © Georg Thieme Verlag KG Stuttgart · New York.

Adjustments in motor unit properties during fatiguing contractions after training.

PubMed

Vila-Chã, Carolina; Falla, Deborah; Correia, Miguel Velhote; Farina, Dario

2012-04-01

The objective of the study was to investigate the effect of strength and endurance training on muscle fiber membrane properties and discharge rates of low-threshold motor units of the vasti muscles during fatiguing contractions. Twenty-five sedentary healthy men (age (mean ± SD) = 26.3 ± 3.9 yr) were randomly assigned to one of three groups: strength training, endurance training, or a control group. Conventional endurance and strength training was performed 3 d·wk⁻¹, during a period of 6 wk. Motor unit conduction velocity and EMG amplitude of the vastus medialis obliquus and lateralis muscles and biceps femoris were measured during sustained isometric knee extensions at 10% and 30% of the maximum voluntary contraction before and immediately after training. After 6 wk of training, the reduction in motor unit conduction velocity during the sustained contractions at 30% of the maximum voluntary force occurred at slower rates compared with baseline (P < 0.05). However, the rate of decrease was lower after endurance training compared with strength training (P < 0.01). For all groups, motor unit discharge rates declined during the sustained contraction (P < 0.001), and their trend was not altered by training. In addition, the biceps femoris-vasti coactivation ratio declined after the endurance training. Short-term strength and endurance training induces alterations of the electrophysiological membrane properties of the muscle fiber. In particular, endurance training lowers the rate of decline of motor unit conduction velocity during sustained contractions more than strength training.

Effects of dry-land vs. in-water specific strength training on professional male water polo players' performance.

PubMed

de Villarreal, Eduardo Sáez; Suarez-Arrones, Luis; Requena, Bernardo; Haff, G Gregory; Ramos-Veliz, Rafael

2014-11-01

We compared the effects of 6-week dry-land and in-water specific strength training combined with a water polo (WP) program on 7 sport-specific performance parameters. Nineteen professional players were randomly assigned to 2 groups: in-water strength group (WSG) (in-water training only) and dry-land strength group (LSG). The program included 3 weekly strength training sessions and 5 days of WP training per week for 6 weeks during the preseason. Ten-meter T-agility test, 20-m maximal sprint swim, maximal dynamic strength (1 repetition maximum), bench press (BP) and full squat (FS), in-water boost, countermovement jump (CMJ), and WP throwing speed were measured. Significant improvements (p ≤ 0.05) were found in the experimental groups in some variables: CMJ in the LSG and WSG (2.35 cm, 9.07%, effect size [ES] = 0.89; and 2.6 cm, 7.6%, ES = 0.83, respectively), in-water boost increased in the WSG group (4.1 cm; 11.48%; ES = 0.70), and FS and BP increased (p ≤ 0.05) only in the LSG group (12.1 kg; 11.27%; ES = 1.15 and 8.3 kg; 9.55%; ES = 1.30, respectively). There was a decrease of performance in agility test (-0.55 seconds; 5.60%; ES = 0.74). Both dry-land and in-water specific strength training and high-intensity training in these male WP players produced medial to large effects on most WP-specific performance parameters. Therefore, we propose modifications to current training methodology for WP players in preseason to include both the training programs (dry-land and in-water specific strength training and high-intensity training) for athlete preparation in this sport.

Different Levels of Eccentric Resistance during Eight Weeks of Training Affect Muscle Strength and Lean Tissue Mass

NASA Technical Reports Server (NTRS)

English, K. L.; Loehr, J. A.; Lee, S. M. C.; Laughlin, M. S.; Hagan, R. D.

2008-01-01

Coupling concentric and eccentric muscle contractions appears to be important in the development of muscle strength and hypertrophy. The interim Resistive Exercise Device (iRED) currently used aboard the International Space Station does not seem to be as effective as free weight training in ambulatory subjects and has not completely protected against muscular deconditioning due to space flight. The lack of protection during space flight could be caused by iRED's proportionally lower eccentric resistance (60-70%) compared to concentric resistance. PURPOSE: To determine the effects of 8 wks of lower body resistive exercise training using five levels of eccentric resistance on muscle strength and lean tissue mass. METHODS: Forty untrained males (34.9 +/- 7 yrs, 80.9 +/- 9.8 kg, 178.2 +/- 7.1 cm; mean +/- SD) completed three 1-repetition maximum (1-RM) strength tests for both the supine leg press (LP) and supine heel raise (HR) prior to training; subjects were matched for LP strength and randomly assigned to one of five training groups. Concentric load (% 1-RM) was constant across groups during training, but each group trained with different levels of eccentric load (0%, 33%, 66%, 100%, or 138% of concentric). Subjects trained 3 d / wk for 8 wks using a periodized program for LP and HR based on percentages of the highest pre-training 1-RM. LP and HR 1-RM and leg lean mass (LLM; assessed by DEXA) were measured pre- and post-training. A two-way ANOVA was used to analyze all dependent measures. Tukey's post hoc tests were used to test significant main effects. Within group pre- to post-training changes were compared using paired t-tests with a Bonferroni adjustment. Statistical significance was set a priori at p 0.05. All data are expressed as mean +/- SE. RESULTS: LP 1-RM strength increased significantly in all groups pre- to post-training. The 138% group increase (20.1 +/- 3.7%) was significantly greater than the 0% (7.9 +/- 2.8%), 33% (7.7 +/- 4.6%), and 66% (7.5 +/- 4.3%) groups. All groups significantly increased HR strength pre- to posttraining (33%: 7.5 +/- 6.1%; 66%: 6.6 +/- 3.7%; 100%: 12.2 +/- 1.8%; 138%: 11.0 +/- 6.4%) except for the 0% (4.9 +/- 9.1%) group. There were no differences between groups. LLM increased significantly pre- to post-training in only the 138% group; there were no differences between groups. CONCLUSIONS: Eight wks of lower body resistive exercise training with eccentric overload resulted in greater increases in LP strength than training with eccentric loads of 66% or less. Post-training HR strength was not affected by eccentric training load, perhaps because of the predominance of Type I fibers typical in the gastrocnemius. Only 138% eccentric training significantly increased LLM. PRACTICAL APPLICATIONS: For athletes or others desiring to maximize muscle strength and hypertrophy gains, training with eccentric loads greater than 100% of concentric resistance will provide greater increases in muscle strength and lean tissue mass in some muscle groups. In a rehabilitation or geriatric exercise setting that places primary emphasis on program adherence and moderate strength gains, training with an eccentric underload may provide strength increases comparable to those of traditional 1:1 training but with less muscle soreness and physiologic insult to the patient, but this has yet to be proven.

Effects of Mental Imagery on Muscular Strength in Healthy and Patient Participants: A Systematic Review

PubMed Central

Slimani, Maamer; Tod, David; Chaabene, Helmi; Miarka, Bianca; Chamari, Karim

2016-01-01

The aims of the present review were to (i) provide a critical overview of the current literature on the effects of mental imagery on muscular strength in healthy participants and patients with immobilization of the upper extremity (i.e., hand) and anterior cruciate ligament (ACL), (ii) identify potential moderators and mediators of the “mental imagery-strength performance” relationship and (iii) determine the relative contribution of electromyography (EMG) and brain activities, neural and physiological adaptations in the mental imagery-strength performance relationship. This paper also discusses the theoretical and practical implications of the contemporary literature and suggests possible directions for future research. Overall, the results reveal that the combination of mental imagery and physical practice is more efficient than, or at least comparable to, physical execution with respect to strength performance. Imagery prevention intervention was also effective in reducing of strength loss after short-term muscle immobilization and ACL. The present review also indicates advantageous effects of internal imagery (range from 2.6 to 136.3%) for strength performance compared with external imagery (range from 4.8 to 23.2%). Typically, mental imagery with muscular activity was higher in active than passive muscles, and imagining “lifting a heavy object” resulted in more EMG activity compared with imagining “lifting a lighter object”. Thus, in samples of students, novices, or youth male and female athletes, internal mental imagery has a greater effect on muscle strength than external mental imagery does. Imagery ability, motivation, and self-efficacy have been shown to be the variables mediating the effect of mental imagery on strength performance. Finally, the greater effects of internal imagery than those of external imagery could be explained in terms of neural adaptations, stronger brain activation, higher muscle excitation, greater somatic and sensorimotor activation and physiological responses such as blood pressure, heart rate, and respiration rate. Key points Coupling mental imagery with physical training is the best suited intervention for improving strength performance. An examination of potential moderator variables revealed that the effectiveness of mental imagery on strength performance may vary depending on the appropriate matching of muscular groups, the characteristics of mental imagery interventions, training duration, and type of skills. Self-efficacy, motivation, and imagery ability were the mediator variables in the mental imagery-strength performance relationship. Greater effects of internal imagery perspective on strength performance than those of external imagery could be explained in terms of neural adaptations, stronger brain activation, higher muscles excitation, greater somatic and sensorimotor activation, and higher physiological responses such as blood pressure, heart rate, and respiration rate. Mental imagery prevention interventions may provide a valuable tool to improve the functional recovery after short-term muscle immobilization and anterior cruciate ligament in patients. PMID:27803622

Physiological Effects of Strength Training and Various Strength Training Devices.

ERIC Educational Resources Information Center

Wilmore, Jack H.

Current knowledge in the area of muscle physiology is a basis for a discussion on strength training programs. It is now recognized that the expression of strength is related to, but not dependent upon, the size of the muscle and is probably more related to the ability to recruit more muscle fibers in the contraction, or to better synchronize their…

Strength and Power Training Effects on Lower Limb Force, Functional Capacity, and Static and Dynamic Balance in Older Female Adults.

PubMed

Lopes, Paula Born; Pereira, Gleber; Lodovico, Angélica; Bento, Paulo C B; Rodacki, André L F

2016-03-03

It has been proposed that muscle power is more effective to prevent falls than muscle force production capacity, as rapid reactions are required to allow the postural control. This study aimed to compare the effects of strength and power training on lower limb force, functional capacity, and static and dynamic balance in older female adults. Thirty-seven volunteered healthy women had been allocated into the strength-training group (n = 14; 69 ± 7.3 years, 155 ± 5.6 cm, 72 ± 9.7 kg), the power-training group (n = 12; 67 ± 7.4 years, 153 ± 5.5 cm, 67.2 ± 7 kg), and control group (n = 11; 65 ± 3.1 years, 154 ± 5.6 cm, 70.9 ± 3 kg). After 12 weeks of training, the strength-training and power-training groups increased significantly maximum dynamic strength (29% and 27%), isometric strength (26% and 37%), and step total time (13% and 14%, dynamic balance), respectively. However, only the power-training group increased the rate of torque development (55%) and the functional capacity in 30-second chair stand (22%) and in time up and go tests (-10%). Empirically, power training may reduce the risk of injuries due to lower loads compared to strength training, and consequently, the physical effort demand during the training session is lower. Therefore, power training should be recommended as attractive training stimuli to improve lower limb force, functional capacity, and postural control of older female adults.

Effects of strength training program on hip extensors and knee extensors strength of lower limb in children with spastic diplegic cerebral palsy.

PubMed

Aye, Thanda; Thein, Soe; Hlaing, Thaingi

2016-01-01

[Purpose] The purpose of this study was to determine whether strength training programs for hip extensors and knee extensors improve gross motor function of children with cerebral palsy in Myanmar. [Subjects and Methods] Forty children (25 boys and 15 girls, mean age: 6.07 ± 2.74 years) from National Rehabilitation Hospital, Yangon, Myanmar, who had been diagnosed with spastic diplegic cerebral palsy, Gross Motor Classification System I and II participated in a 6-week strength training program (45 minutes per day, 3 days per week) on hip and knee extensors. Assessment was made, before and after intervention, of the amount of training weight in pounds, as well as Gross Motor Function Measure (GMFM) dimensions D (standing) and E (walking, running, jumping). [Results] All scores had increased significantly after the strength-training program. [Conclusion] A simple method of strength-training program for hip and knee extensors might lead to improved muscle strength and gross motor function in children with spastic diplegic cerebral palsy.

Effects of strength training program on hip extensors and knee extensors strength of lower limb in children with spastic diplegic cerebral palsy

PubMed Central

Aye, Thanda; Thein, Soe; Hlaing, Thaingi

2016-01-01

[Purpose] The purpose of this study was to determine whether strength training programs for hip extensors and knee extensors improve gross motor function of children with cerebral palsy in Myanmar. [Subjects and Methods] Forty children (25 boys and 15 girls, mean age: 6.07 ± 2.74 years) from National Rehabilitation Hospital, Yangon, Myanmar, who had been diagnosed with spastic diplegic cerebral palsy, Gross Motor Classification System I and II participated in a 6-week strength training program (45 minutes per day, 3 days per week) on hip and knee extensors. Assessment was made, before and after intervention, of the amount of training weight in pounds, as well as Gross Motor Function Measure (GMFM) dimensions D (standing) and E (walking, running, jumping). [Results] All scores had increased significantly after the strength-training program. [Conclusion] A simple method of strength-training program for hip and knee extensors might lead to improved muscle strength and gross motor function in children with spastic diplegic cerebral palsy. PMID:27065561

[Health-related strength and power training in seniors: Purpose and recommendations].

PubMed

Donath, Lars; Faude, Oliver; Bopp, Micha; Zahner, Lukas

2015-05-01

The proportion of older people in western societies rapidly increases. Aging-induced disease conditions accompanied with declines in cardiocirculatory and neuromuscular performance constitute a major individual and economic health burden. Besides decreasing vascular and cardiac function during the process of aging, a loss of skeletal muscle mass, muscle structure and function seem to mainly account for decreasing maximal strength, strength development and strength endurance. These findings adversely interfer with static and dynamic postural control and may lead to an increased risk of falling with impairments of autonomy and quality of life. Traditional strength training recommendations basing on health-related exercise prescriptions for elderly people have been proven to counteract or at least attenuate aging-induced declines of neuromuscular muscular function. Multimodal and combined strength and balance training deliver additional improvements of neuromuscular capacity. Recent evidence additionally underpin the need of trunk muscle training and claimed for regimes considering explosive and high-velocity strength training in seniors. High quality RCTs revealed notable strength training effects on mobility, autonomy, quality of life and the reduction of the risk of falling (up to 50%). Available evidence also indicates that various strength training regimes elicit preventive and therapeutic effects on osteoporosis, diabetes type 2 and other chronic diseases, with effect sizes comparable to medication intake. Thus, health care providers, health insurances, Employers' Liability Insurance Associations and politicians should promote infrastructural developments that enable feasible and cost-effective access to health-related fitness centers or other sport facilities (e. g. sport clubs). These environmental requirements should be embedded in multi-centric education programs and campaigns that might enable regularly conducted strength and endurance training perceived as beneficial and valuable from an individual health care perspective.

Effect of traditional resistance and power training using rated perceived exertion for enhancement of muscle strength, power, and functional performance.

PubMed

Tiggemann, Carlos Leandro; Dias, Caroline Pieta; Radaelli, Regis; Massa, Jéssica Cassales; Bortoluzzi, Rafael; Schoenell, Maira Cristina Wolf; Noll, Matias; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins

2016-04-01

The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p < 0.001) and similarly in both groups after training. Muscle power also increased with training (≈27 %; p < 0.05), with no difference between groups. Both groups also improved their functional performance after training period (≈13 %; p < 0.001), with no difference between groups. The present study showed that TRT and PT using RPE scale to control intensity were significantly and similarly effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.

Strength Training. A Key to Athletic Training.

ERIC Educational Resources Information Center

Whiteside, Patricia W.

Characteristics of an effective strength training program are analyzed and descriptions are offered of different kinds of weight training activities. Comparisons are made between concentric, isometric, eccentric, and isokinetic training methods. The fundamentals and techniques of an exemplary training program are outlined and the organization and…

Cycle training induces muscle hypertrophy and strength gain: strategies and mechanisms.

PubMed

Ozaki, Hayao; Loenneke, J P; Thiebaud, R S; Abe, T

2015-03-01

Cycle training is widely performed as a major part of any exercise program seeking to improve aerobic capacity and cardiovascular health. However, the effect of cycle training on muscle size and strength gain still requires further insight, even though it is known that professional cyclists display larger muscle size compared to controls. Therefore, the purpose of this review is to discuss the effects of cycle training on muscle size and strength of the lower extremity and the possible mechanisms for increasing muscle size with cycle training. It is plausible that cycle training requires a longer period to significantly increase muscle size compared to typical resistance training due to a much slower hypertrophy rate. Cycle training induces muscle hypertrophy similarly between young and older age groups, while strength gain seems to favor older adults, which suggests that the probability for improving in muscle quality appears to be higher in older adults compared to young adults. For young adults, higher-intensity intermittent cycling may be required to achieve strength gains. It also appears that muscle hypertrophy induced by cycle training results from the positive changes in muscle protein net balance.

Heavy section fracture toughness screening specimen

NASA Technical Reports Server (NTRS)

Shannon, J. L., Jr.; Donald, J. K.; Brown, W. F., Jr.

1976-01-01

Size requirements for a pin loaded double edge notch + crack tension specimen proposed for fracture toughness screening heavy section alloys were studied. Ranking of eight selected alloys based on the specimen's net strength was compared with that based on the valid plane strain fracture toughness separately determined. Performance of the specimen was judged on the basis of that comparison. The specimen's net strength was influenced by three critical specimen dimensions: distance between the crack plane and the loading hole, specimen width, and specimen thickness. Interaction between the stress fields of the crack and the loading holes reduced the net strength, but this effect disappeared as the separation reached a dimension equal to the specimen width. The effects of specimen width and thickness are interrelated and affect the net strength through their influence on the development of the crack tip plastic zone.

Hydration and leaching characteristics of cement pastes made from electroplating sludge.

PubMed

Chen, Ying-Liang; Ko, Ming-Sheng; Lai, Yi-Chieh; Chang, Juu-En

2011-06-01

The purpose of this study was to investigate the hydration and leaching characteristics of the pastes of belite-rich cements made from electroplating sludge. The compressive strength of the pastes cured for 1, 3, 7, 28, and 90 days was determined, and the condensation of silicate anions in hydrates was examined with the (29)Si nuclear magnetic resonance (NMR) technology. The leachabilities of the electroplating sludge and the hardened pastes were studied with the multiple toxicity characteristic leaching procedure (MTCLP) and the tank leaching test (NEN 7345), respectively. The results showed that the electroplating sludge continued to leach heavy metals, including nickel, copper, and zinc, and posed a serious threat to the environment. The belite-rich cement made from the electroplating sludge was abundant in hydraulic β-dicalcium silicate, and it performed well with regard to compressive-strength development when properly blended with ordinary Portland cements. The blended cement containing up to 40% the belite-rich cement can still satisfy the compressive-strength requirements of ASTM standards, and the pastes cured for 90 days had comparable compressive strength to an ordinary Portland cement paste. It was also found that the later hydration reaction of the blended cements was relatively more active, and high fractions of belite-rich cement increased the chain length of silicate hydrates. In addition, by converting the sludge into belite-rich cements, the heavy metals became stable in the hardened cement pastes. This study thus indicates a viable alternative approach to dealing with heavy metal bearing wastes, and the resulting products show good compressive strength and heavy-metal stability. Copyright © 2011 Elsevier Ltd. All rights reserved.

The effect of progressive resistance training on aerobic fitness and strength in adults with coronary heart disease: A systematic review and meta-analysis of randomised controlled trials.

PubMed

Hollings, Matthew; Mavros, Yorgi; Freeston, Jonathan; Fiatarone Singh, Maria

2017-08-01

Design We aimed to evaluate the effect of progressive resistance training on cardiorespiratory fitness and muscular strength in coronary heart disease, when compared to control or aerobic training, and when combined with aerobic training. Secondary aims were to evaluate the safety and efficacy of progressive resistance training on other physiological and clinical outcomes. Methods and results Electronic databases were searched from inception until July 2016. Designs included progressive resistance training vs control, progressive resistance training vs aerobic training, and combined training vs aerobic training. From 268,778 titles, 34 studies were included (1940 participants; 71.9% male; age 60 ± 7 years). Progressive resistance training was more effective than control for lower (standardized mean difference 0.57, 95% confidence interval (0.17-0.96)) and upper (1.43 (0.73-2.13)) body strength. Aerobic fitness improved similarly after progressive resistance training (16.9%) or aerobic training (21.0%); (standardized mean difference -0.13, 95% confidence interval (-0.35-0.08)). Combined training was more effective than aerobic training for aerobic fitness (0.21 (0.09-0.34), lower (0.62 (0.32-0.92)) and upper (0.51 (0.27-0.74)) body strength. Twenty studies reported adverse event information, with five reporting 64 cardiovascular complications, 63 during aerobic training. Conclusion Isolated progressive resistance training resulted in an increase in lower and upper body strength, and improved aerobic fitness to a similar degree as aerobic training in coronary heart disease cohorts. Importantly, when progressive resistance training was added to aerobic training, effects on both fitness and strength were enhanced compared to aerobic training alone. Reporting of adverse events was poor, and clinical gaps were identified for women, older adults, high intensity progressive resistance training and long-term outcomes, warranting future trials to confirm safety and effectiveness.

Burrowing as a novel voluntary strength training method for mice: A comparison of various voluntary strength or resistance exercise methods.

PubMed

Roemers, P; Mazzola, P N; De Deyn, P P; Bossers, W J; van Heuvelen, M J G; van der Zee, E A

2018-04-15

Voluntary strength training methods for rodents are necessary to investigate the effects of strength training on cognition and the brain. However, few voluntary methods are available. The current study tested functional and muscular effects of two novel voluntary strength training methods, burrowing (digging a substrate out of a tube) and unloaded tower climbing, in male C57Bl6 mice. To compare these two novel methods with existing exercise methods, resistance running and (non-resistance) running were included. Motor coordination, grip strength and muscle fatigue were measured at baseline, halfway through and near the end of a fourteen week exercise intervention. Endurance was measured by an incremental treadmill test after twelve weeks. Both burrowing and resistance running improved forelimb grip strength as compared to controls. Running and resistance running increased endurance in the treadmill test and improved motor skills as measured by the balance beam test. Post-mortem tissue analyses revealed that running and resistance running induced Soleus muscle hypertrophy and reduced epididymal fat mass. Tower climbing elicited no functional or muscular changes. As a voluntary strength exercise method, burrowing avoids the confounding effects of stress and positive reinforcers elicited in forced strength exercise methods. Compared to voluntary resistance running, burrowing likely reduces the contribution of aerobic exercise components. Burrowing qualifies as a suitable voluntary strength training method in mice. Furthermore, resistance running shares features of strength training and endurance (aerobic) exercise and should be considered a multi-modal aerobic-strength exercise method in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of maturation on adaptations to strength training and detraining in 11-15-year-olds.

PubMed

Meylan, C M P; Cronin, J B; Oliver, J L; Hopkins, W G; Contreras, B

2014-06-01

To investigate how maturity status modifies the effects of strength training and detraining on performance, we subjected 33 young men to 8 weeks of strength training twice per week followed by 8 weeks without training. Changes in performance tests were analyzed in three maturity groups based on years from/to age of predicted peak height velocity (PHV): pre-PHV (-1.7 ± 0.4 years; n = 10), mid-PHV (-0.2 ± 0.4 years; n = 11), and post-PHV (1.0 ± 0.4 years; n = 12). Mean training effects on one repetition maximum strength (3.6-10.0%), maximum explosive power (11-20%), jump length (6.5-7.4%), and sprint times (-2.1% to -4.7%) ranged from small to large, with generally greater changes in mid- and post-PHV groups. Changes in force-velocity relationships reflected generally greater increases in strength at faster velocities. In the detraining period, the pre-PHV group showed greatest loss of strength and power, the post-PHV group showed some loss of sprint performance, but all groups maintained or improved jump length. Strength training was thus generally less effective before the growth spurt. Maintenance programs are needed for most aspects of explosive performance following strength training before the growth spurt and for sprint speed after the growth spurt. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Effects of endurance training only versus same-session combined endurance and strength training on physical performance and serum hormone concentrations in recreational endurance runners.

PubMed

Schumann, Moritz; Mykkänen, Olli-Pekka; Doma, Kenji; Mazzolari, Raffaele; Nyman, Kai; Häkkinen, Keijo

2015-01-01

This study investigated the effects of endurance training only (E, n = 14) and same-session combined training, when strength training is repeatedly preceded by endurance loading (endurance and strength training (E+S), n = 13) on endurance (1000-m running time during incremental field test) and strength performance (1-repetition maximum (1RM) in dynamic leg press), basal serum hormone concentrations, and endurance loading-induced force and hormone responses in recreationally endurance-trained men. E was identical in the 2 groups and consisted of steady-state and interval running, 4-6 times per week for 24 weeks. E+S performed additional mixed-maximal and explosive-strength training (2 times per week) immediately following an incremental running session (35-45 min, 65%-85% maximal heart rate). E and E+S decreased running time at week 12 (-8% ± 5%, p = 0.001 and -7% ± 3%, p < 0.001) and 24 (-13% ± 5%, p < 0.001 and -9% ± 5%, p = 0.001). Strength performance decreased in E at week 24 (-5% ± 5%, p = 0.014) but was maintained in E+S (between-groups at week 12 and 24, p = 0.014 and 0.011, respectively). Basal serum testosterone and cortisol concentrations remained unaltered in E and E+S but testosterone/sex hormone binding globulin ratio decreased in E+S at week 12 (-19% ± 26%, p = 0.006). At week 0 and 24, endurance loading-induced acute force (-5% to -9%, p = 0.032 to 0.001) and testosterone and cortisol responses (18%-47%, p = 0.013 to p < 0.001) were similar between E and E+S. This study showed no endurance performance benefits when strength training was performed repeatedly after endurance training compared with endurance training only. This was supported by similar acute responses in force and hormonal measures immediately post-endurance loading after the training with sustained 1RM strength in E+S.

Myosin heavy chain profile of equine gluteus medius muscle following prolonged draught-exercise training and detraining.

PubMed

Serrano, A L; Rivero, J L

2000-04-01

Fourteen 4-year old Andalusian mares were used to examine the plasticity of myosin heavy chain (MHC) composition in horse skeletal muscle with heavy draught-exercise training and detraining. Seven horses underwent a training programme based on carriage exercises for 8 months. Afterwards, they were kept in paddocks for 3 months. The remaining seven animals were used as control horses. Three gluteus medius muscle biopsies were removed at depths of 20, 40 and 60 mm from each horse before (month 0), during the training (months 3 and 8) and after detraining (month 11). Myosin heavy chain composition was analysed by electrophoresis and immunohistochemically with anti-MHC monoclonal antibodies. Fibre areas, oxidative capacity and capillaries were studied histochemically. After 8 months of training, MHC-IIX and IIX fibres decreased whereas MHC-I and type I and I + IIA fibres increased. Neither MHC-IIA nor the percentage of IIA fibres changed when the data were considered as a whole, but the proportion of MHC-IIA increased in the superficial region of the muscle after 8 months of training. Mean areas of type II fibres were not affected by training and detraining, but the cross-sectional of type I fibres increased after 3 month of training and not further increases were recorded afterward. The percentage of high-oxidative capacity fibres and the number of capillaries per mm2 increased with training. Most of these muscular adaptations reverted after detraining. These results indicate that long term draught-exercise training induces a reversible transition of MHC composition in equine muscle in the order IIX --> IIA --> I. The physiological implication of these changes is an impact on the velocity of shortening and fatigue resistance of muscle fibres.

Single muscle fiber adaptations with marathon training.

PubMed

Trappe, Scott; Harber, Matthew; Creer, Andrew; Gallagher, Philip; Slivka, Dustin; Minchev, Kiril; Whitsett, David

2006-09-01

The purpose of this investigation was to characterize the effects of marathon training on single muscle fiber contractile function in a group of recreational runners. Muscle biopsies were obtained from the gastrocnemius muscle of seven individuals (22 +/- 1 yr, 177 +/- 3 cm, and 68 +/- 2 kg) before, after 13 wk of run training, and after 3 wk of taper. Slow-twitch myosin heavy chain [(MHC) I] and fast-twitch (MHC IIa) muscle fibers were analyzed for size, strength (P(o)), speed (V(o)), and power. The run training program led to the successful completion of a marathon (range 3 h 56 min to 5 h 35 min). Oxygen uptake during submaximal running and citrate synthase activity were improved (P < 0.05) with the training program. Muscle fiber size declined (P < 0.05) by approximately 20% in both fiber types after training. P(o) was maintained in both fiber types with training and increased (P < 0.05) by 18% in the MHC IIa fibers after taper. This resulted in >60% increase (P < 0.05) in force per cross-sectional area in both fiber types. Fiber V(o) increased (P < 0.05) by 28% in MHC I fibers with training and was unchanged in MHC IIa fibers. Peak power increased (P < 0.05) in MHC I and IIa fibers after training with a further increase (P < 0.05) in MHC IIa fiber power after taper. These data show that marathon training decreased slow-twitch and fast-twitch muscle fiber size but that it maintained or improved the functional profile of these fibers. A taper period before the marathon further improved the functional profile of the muscle, which was targeted to the fast-twitch muscle fibers.

Effects of different strength training frequencies on maximum strength, body composition and functional capacity in healthy older individuals.

PubMed

Turpela, Mari; Häkkinen, Keijo; Haff, Guy Gregory; Walker, Simon

2017-11-01

There is controversy in the literature regarding the dose-response relationship of strength training in healthy older participants. The present study determined training frequency effects on maximum strength, muscle mass and functional capacity over 6months following an initial 3-month preparatory strength training period. One-hundred and six 64-75year old volunteers were randomly assigned to one of four groups; performing strength training one (EX1), two (EX2), or three (EX3) times per week and a non-training control (CON) group. Whole-body strength training was performed using 2-5 sets and 4-12 repetitions per exercise and 7-9 exercises per session. Before and after the intervention, maximum dynamic leg press (1-RM) and isometric knee extensor and plantarflexor strength, body composition and quadriceps cross-sectional area, as well as functional capacity (maximum 7.5m forward and backward walking speed, timed-up-and-go test, loaded 10-stair climb test) were measured. All experimental groups increased leg press 1-RM more than CON (EX1: 3±8%, EX2: 6±6%, EX3: 10±8%, CON: -3±6%, P<0.05) and EX3 improved more than EX1 (P=0.007) at month 9. Compared to CON, EX3 improved in backward walk (P=0.047) and EX1 in timed-up-and-go (P=0.029) tests. No significant changes occurred in body composition. The present study found no evidence that higher training frequency would induce greater benefit to maximum walking speed (i.e. functional capacity) despite a clear dose-response in dynamic 1-RM strength, at least when predominantly using machine weight-training. It appears that beneficial functional capacity improvements can be achieved through low frequency training (i.e. 1-2 times per week) in previously untrained healthy older participants. Copyright © 2017 Elsevier Inc. All rights reserved.

Study on longitudinal force simulation of heavy-haul train

NASA Astrophysics Data System (ADS)

Chang, Chongyi; Guo, Gang; Wang, Junbiao; Ma, Yingming

2017-04-01

The longitudinal dynamics model of heavy-haul trains and air brake model used in the longitudinal train dynamics (LTDs) are established. The dry friction damping hysteretic characteristic of steel friction draft gears is simulated by the equation which describes the suspension forces in truck leaf springs. The model of draft gears introduces dynamic loading force, viscous friction of steel friction and the damping force. Consequently, the numerical model of the draft gears is brought forward. The equation of LTDs is strongly non-linear. In order to solve the response of the strongly non-linear system, the high-precision and equilibrium iteration method based on the Newmark-β method is presented and numerical analysis is made. Longitudinal dynamic forces of the 20,000 tonnes heavy-haul train are tested, and models and solution method provided are verified by the test results.

Strength Training for Young Athletes.

ERIC Educational Resources Information Center

Kraemer, William J.; Fleck, Steven J.

This guide is designed to serve as a resource for developing strength training programs for children. Chapter 1 uses research findings to explain why strength training is appropriate for children. Chapter 2 explains some of the important physiological concepts involved in children's growth and development as they apply to developing strength…

Effects of Directional Exercise on Lingual Strength

ERIC Educational Resources Information Center

Clark, Heather M.; O'Brien, Katy; Calleja, Aimee; Corrie, Sarah Newcomb

2009-01-01

Purpose: To examine the application of known muscle training principles to tongue strengthening exercises and to answer the following research questions: (a) Did lingual strength increase following 9 weeks of training? (b) Did training conducted using an exercise moving the tongue in one direction result in strength changes for tongue movements in…

Women's Strength Training. Lifting the Limits of Aging?

ERIC Educational Resources Information Center

Cinque, Chris

1990-01-01

Strength training is considered a male activity, but physicians are recommending it to women who want to keep their musculoskeletal systems strong and flexible as they age. This article discusses goals and problems of strength training for women and suggests it as an adjunct to cardiovascular fitness exercises. (SM)

ASE Program Certification Standards for Medium/Heavy Truck Technician Training Programs.

ERIC Educational Resources Information Center

National Automotive Technicians Education Foundation, Herndon, VA.

This publication provides the evaluation policies, procedures, and standards to which a medium/heavy truck technician training program must adhere to be granted certification by the National Institute for Automotive Service Excellence. The policies section has three parts: the automobile areas that may be certified and minimum requirements for…

Effects of a Strength Training Session After an Exercise Inducing Muscle Damage on Recovery Kinetics.

PubMed

Abaïdia, Abd-Elbasset; Delecroix, Barthélémy; Leduc, Cédric; Lamblin, Julien; McCall, Alan; Baquet, Georges; Dupont, Grégory

2017-01-01

Abaïdia, A-E, Delecroix, B, Leduc, C, Lamblin, J, McCall, A, Baquet, G, and Dupont, G. Effects of a strength training session after an exercise inducing muscle damage on recovery kinetics. J Strength Cond Res 31(1): 115-125, 2017-The purpose of this study was to investigate the effects of an upper-limb strength training session the day after an exercise inducing muscle damage on recovery of performance. In a randomized crossover design, subjects performed the day after the exercise, on 2 separate occasions (passive vs. active recovery conditions) a single-leg exercise (dominant in one condition and nondominant in the other condition) consisting of 5 sets of 15 eccentric contractions of the knee flexors. Active recovery consisted of performing an upper-body strength training session the day after the exercise. Creatine kinase, hamstring strength, and muscle soreness were assessed immediately and 20, 24, and 48 hours after exercise-induced muscle damage. The upper-body strength session, after muscle-damaging exercise accelerated the recovery of slow concentric force (effect size = 0.65; 90% confidence interval = -0.06 to 1.32), but did not affect the recovery kinetics for the other outcomes. The addition of an upper-body strength training session the day after muscle-damaging activity does not negatively affect the recovery kinetics. Upper-body strength training may be programmed the day after a competition.

Effects of Training Attendance on Muscle Strength of Young Men after 11 Weeks of Resistance Training

PubMed Central

Gentil, Paulo; Bottaro, Martim

2013-01-01

Purpose Training attendance is an important variable for attaining optimal results after a resistance training (RT) program, however, the association of attendance with the gains of muscle strength is not well defined. Therefore, the purpose of the present study is to verify if attendance would affect muscle strength gains in healthy young males. Methods Ninety two young males with no previous RT experience volunteered to participate in the study. RT was performed 2 days a week for 11 weeks. One repetition maximum (1RM) in the bench press and knee extensors peak torque (PT) were measured before and after the training period. After the training period, a two step cluster analysis was used to classify the participants in accordance to training attendance, resulting in three groups, defined as high (92 to 100%), intermediate (80 to 91%) and low (60 to 79%) training attendance. Results According to the results, there were no significant correlations between strength gains and training attendance, however, when attendance groups were compared, the low training attendance group showed lower increases in 1RM bench press (8.8%) than the other two groups (17.6% and 18.0% for high and intermediate attendance, respectively). Conclusions Although there is not a direct correlation between training attendance and muscle strength gains, it is suggested that a minimum attendance of 80% is necessary to ensure optimal gains in upper body strength. PMID:23802051

The effects of strength and endurance training in patients with rheumatoid arthritis.

PubMed

Strasser, Barbara; Leeb, Gunther; Strehblow, Christoph; Schobersberger, Wolfgang; Haber, Paul; Cauza, Edmund

2011-05-01

Patients with rheumatoid arthritis (RA) suffer from muscle loss, causing reduced muscle strength and endurance. The current study aimed to: (1) evaluate the effects of combined strength and endurance training (CT) on disease activity and functional ability in patients with RA and (2) investigate the benefits of a 6-month supervised CT program on muscle strength, cardio-respiratory fitness, and body composition of RA patients. Forty patients with RA, aged 41-73 years, were recruited for the current study. Twenty of these patients (19 females, one male) were randomly assigned to a 6-month supervised CT program; 20 patients (17 females, three males) served as controls. Within the CT program, strength training consisted of sets of weight bearing exercises for all major muscle groups. In addition to strength training, systematic endurance training was performed on a cycle ergometer two times per week. For RA patients involved in CT, disease activity (p = 0.06) and pain (p = 0.05) were reduced after the 6-month training period while general health (p = 0.04) and functional ability (p = 0.06) improved. Cardio-respiratory endurance was found to have improved significantly (by 10%) after 6 months of CT (p < 0.001). The overall strength of patients undertaking CT increased by an average of 14%. Lean body mass increased, and the percentage of body fat was found to decrease significantly (p < 0.05). A combination of strength and endurance training resulted in considerable improvements in RA patients' muscle strength and cardio-respiratory endurance, accompanied by positive changes in body composition and functional ability. Long-term training appears to be effective in reducing disease activity and associated pain and was found to have no deleterious effects.

Effects of Hip Strengthening on Neuromuscular Control, Hip Strength, and Self-Reported Functional Deficits in Individuals With Chronic Ankle Instability.

PubMed

Smith, Brent I; Curtis, Denice; Docherty, Carrie L

2018-06-12

Deficits in ankle and hip strength and lower-extremity postural control are associated with chronic ankle instability (CAI). Following strength training, muscle groups demonstrate increased strength. This change is partially credited to improved neuromuscular control, and many studies have investigated ankle protocols for subjects with CAI. The effects of isolating hip musculature in strength training protocols in this population are not well understood. To examine the effects of hip strengthening on clinical and self-reported outcomes in patients with CAI. Prospective randomized controlled clinical trial. Athletic training facility. Twenty-six participants with CAI (12 males and 14 females; age = 20.9 [1.5] y, height = 170.0 [12.7] cm, and mass = 77.5 [17.5] kg) were randomly assigned to training or control groups. Participants completed either 4 weeks of supervised hip strengthening (resistance bands 3 times a week) or no intervention. Participants were assessed on 4 clinical measures (Star Excursion Balance Test in the anterior, posteromedial, and posterolateral directions; Balance Error Scoring System; hip external rotation strength; and hip abduction strength) and a patient-reported measure (the Foot and Ankle Ability Measure activities of daily living and sports subscales) before and after the 4-week training period. The training group displayed significantly improved posttest measures compared with the control group for hip abduction strength (training: 446.3 [77.4] N, control: 314.7 [49.6] N, P < .01); hip external rotation strength (training: 222.1 [48.7] N, control: 169.4 [34.6] N, P < .01); Star Excursion Balance Test reach in the anterior (training: 93.1% [7.4%], control: 90.2% [7.9%], P < .01), posteromedial (training: 96.3% [8.9%], control: 88.0% [8.8%], P < .01), and posterolateral (training: 95.4% [11.1%], control: 86.6% [9.6%], P < .01) directions; Balance Error Scoring System total errors (training: 9.9 [6.3] errors, control: 21.2 [6.3] errors, P < .01); and the Foot and Ankle Ability Measure-sports score (training: 88.0 [12.6], control: 84.8 [10.9], P < .01). Improved clinical and patient-reported outcomes in the training group suggest hip strengthening is beneficial in the management and prevention of recurrent symptoms associated with CAI.

A comparison of maximal squat strength and 5-, 10-, and 20-meter sprint times, in athletes and recreationally trained men.

PubMed

Comfort, Paul; Bullock, Nathan; Pearson, Stephen J

2012-04-01

The purpose of this study was to identify whether there was a relationship between relative strength during a 1 repetition maximum (1RM) back squat and 5-, 10-, and 20-m sprint performances in both trained athletes and recreationally trained individuals. Professional rugby league players (n = 24) and recreationally trained individuals (n = 20) participated in this investigation. Twenty-meter sprint time and 1RM back squat strength, using free weights, were assessed on different days. There were no significant (p ≥ 0.05) differences between the well-trained and recreationally trained groups for 5-m sprint times. In contrast, the well-trained group's 10- and 20-m sprint times were significantly quicker (p = 0.004; p = 0.002) (1.78 + 0.06 seconds; 3.03 + 0.09 seconds) compared with the recreationally trained group (1.84 + 0.07 seconds; 3.13 + 0.11 seconds). The athletes were significantly stronger (170.63 + 21.43 kg) than the recreationally trained individuals (135.45 + 30.07 kg) (p = 0.01); however, there were no significant differences (p > 0.05) in relative strength between groups (1.78 + 0.27 kg/kg; 1.78 + 0.33 kg/kg, respectively). Significant negative correlations were found between 5-m sprint time and relative squat strength (r = -0.613, power = 0.96, p = 0.004) and between relative squat strength and 10- and 20-m sprint times in the recreationally trained group (r = -0.621, power = 0.51, p = 0.003; r = -0.604, power = 0.53, p = 0.005, respectively). These results, indicating that relative strength, are important for initial sprint acceleration in all athletes but more strongly related to sprint performance over greater distances in recreationally trained individuals.

Creatine monohydrate supplementation during eight weeks of progressive resistance training increases strength in as little as two weeks without reducing markers of muscle damage.

PubMed

Kaviani, Mojtaba; Abassi, Aboozar; Chilibeck, Philip D

2018-05-02

Creatine supplementation (Cr) increases strength during resistance training, but the time course of this strength increase is unclear. The aim was to determine the precise time course by which Cr could increase strength and whether Cr prevents muscle damage during eight weeks of resistance training. Young males were randomized (double blind) to Cr (n=9, 0.07g/kg/d) and placebo (n=9) during 8-weeks of resistance training (3d/week). Strength was assessed across six exercises every two weeks. Venous blood samples obtained at baseline, and 24 and 48 hours after the final resistance training session were assessed for creatine kinase [CK] and lactate dehydrogenase [LDH] as measures of muscle damage. Strength was significantly higher in the Cr versus placebo group (p<0.05) after two weeks of training for three of the six exercises (bench press, leg press, shoulder press). By the end of the eight weeks of training, strength was significantly higher in the Cr versus placebo group (p<0.05) for four of the six exercises (bench press, leg press, shoulder press, and triceps extension, but not biceps curl or lat-pulldown). Creatine supplementation did not prevent muscle damage. Indeed, muscle damage markers increased in the Cr compared to placebo group (p<0.05). Cr increased muscular strength in as little as two weeks during a resistance training program; however, this was not accompanied by decreased muscle damage. Greater muscle damage with Cr may be due to a greater training intensity enabled by Cr supplementation. This might lead to greater protein turnover and enhanced muscle adaptation.

A Strength Training Program for Primary Care Patients, Central Pennsylvania, 2012

PubMed Central

Patel, Vijay A.; Kraschnewski, Jennifer L.; Rovniak, Liza S.; Messina, Dino A.; Stuckey, Heather L.; Curry, William J.; Chuang, Cynthia H.; Sherwood, Lisa L.; Hess, Stacy L.

2014-01-01

Introduction Primary care providers can recommend strength training programs to use “Exercise as Medicine,” yet few studies have examined the interest of primary care patients in these programs. Methods We conducted a cross-sectional survey of primary care patients in central Pennsylvania. Interest in participating in free group-based strength training and weight control programs was assessed, in addition to patient demographics, medical history, and quality of life. Results Among 414 patients, most (61.0%) were aged 54 or older, and 64.0% were female. More patients were interested in a strength training program (55.3%) than in a weight control program (45.4%). Nearly three-quarters (72.8%) of those reporting 10 or more days of poor physical health were interested in a strength training program compared with 49.5% of those reporting no days of poor physical health. After adjusting for potential confounders, those reporting poorer physical health had 2.7 greater odds (95% confidence interval, 1.4–5.1) of being interested in a strength training program compared with those reporting better physical health. Patients with hypertension, diabetes, or high cholesterol were not more interested in a strength training program than those without these conditions. Conclusion Primary care practices may consider offering or referring patients to community-based strength training programs. This study observed high levels of interest in these widely available programs. Practices may also consider screening and referring those with poorer physical health, as they may be the most interested and have the most to gain from participating. PMID:24967829

Strength training and body composition in middle-age women.

PubMed

Burrup, Rachelle; Tucker, Larry A; LE Cheminant, James D; Bailey, Bruce W

2018-01-01

Strength training is a sound method to improve body composition. However, the effect of age, diet, menopause, and physical activity on the relationship between strength training and body composition in women remains unknown. The purpose of this study was to examine the intricacies of the relationship between strength training and body composition in 257 middle-age women and to quantify the effect of these factors on the association. The study was cross-sectional. Five variables were used to index strength training participation. Body composition was assessed by dual-energy X-ray absorptiometry. Diet was assessed by 7-day weighed food records, and physical activity was measured objectively using accelerometers. There were 109 strength trainers in the sample. For each day per week of strength training, body fat was 1.3 percentage points lower (F=14.8, P<0.001) and fat-free mass was 656 g higher (F=18.9, P<0.001). Likewise, the more time women spent lifting and the more intensely they trained, the better their body composition tended to be. Differences in age, energy and protein consumption had little effect on the associations. However, adjusting for differences in physical activity, and to a lesser extent, menopause status, weakened the relationships significantly. The more days, time, and effort women devote to strength training, the lower their body fat and the higher their fat-free mass tend to be. A significant portion of the differences in body composition seems to result from lifters participating in more physical activity than non-lifters. Menopause status also contributes significantly to the relationship.

The Acute Effect of Concurrent Training on Running Performance over 6 Days

ERIC Educational Resources Information Center

Doma, Kenji; Deakin, Glen

2015-01-01

Purpose: This study examined the effects of strength training on alternating days and endurance training on consecutive days on running performance for 6 days. Methods: Sixteen male and 8 female moderately trained individuals were evenly assigned into concurrent-training (CCT) and strength-training (ST) groups. The CCT group undertook strength…

Circuit strength training improves muscle strength, functional performance and anthropometric indicators in sedentary elderly women.

PubMed

Mazini Filho, Mauro L; Aidar, Felipe J; Gama de Matos, Dihogo; Costa Moreira, Osvaldo; Patrocínio de Oliveira, Cláudia E; de Oliveira Venturini, Gabriela R; Magalhães Curty, Victor; Menezes Touguinha, Henrique; Caputo Ferreira, Maria E

2017-04-26

This study aimed to investigate the effects of circuit strength training on the muscle strength, functional autonomy and anthropometric indicators of the elderly. Were included 65 women divided in two groups: strength training (TG, n= 34) and control group (CG, n = 31). The strength-training group was subjected to a circuit shaped training program, three days per week, for a period of 12 weeks. In each training session, the circuit was repeated three times. In each circuit, all exercises wereperformed once, with 8 to 12 repetitions per exercise, with 30-seconds intervals between each exercise. TG showed significantly changes in body composition post 12 weeks, as decreases in body weight (Δ -1.5±1.8 kg) and BMI (Δ-0.57 ±0.74 kg/m²), and decreases in abdominal (Δ -3±1.61 cm), waist (Δ -1 ± 1.61 cm), hip (Δ -2.75±1.44 cm) and waist hip ratio circumference (Δ -0.02 ± 0.15 cm). For functional autonomy, TG showed increases post 12 weeks by 30-second chair stand (Δ 3.5±0.4 reps), six minute walk (Δ60.95±7.91 m), back scratch (Δ 3.2 ± 1.36 cm), and time up and go tests (Δ -1,62 ±0,15s). TG also showed increases in muscle strength post 12 weeks in both leg press (Δ 11±1,29 kg) and lat pulldown (Δ11 ±0,75 Kg). For CG, Body composition, functional autonomy and muscle strength did not improved in any moment. Hence, circuit strength training provides significant improvements inmuscle strength, functional performance and anthropometric indicators in sedentary elderly women.

The effects of two equal-volume training protocols upon strength, body composition and salivary hormones in male rugby union players

PubMed Central

Heke, TOL; Keogh, JWL

2016-01-01

This study examined the effects of two equal-volume resistance-training protocols upon strength, body composition and salivary hormones in male rugby union players. Using a crossover design, 24 male rugby players completed a 4-week full-body (FB) and split-body (SB) training protocol of equal volume during the competitive season. One repetition maximum (1RM) strength, body composition via skinfold measurements and salivary testosterone (T) and cortisol (C) concentrations were assessed pre and post training. The FB and SB protocols improved upper (7.3% and 7.4%) and lower body 1RM strength (7.4% and 5.4%), whilst reducing body fat (-0.9% and -0.4%) and fat mass (-5.7% and -2.1%), respectively (all p ≤ 0.021). The SB protocol elevated T (21%) and C (50%) concentrations with a higher T/C ratio (28%) after FB training (all p ≤ 0.039). The strength changes were similar, but the body composition and hormonal results differed by protocol. Slope testing on the individual responses identified positive associations (p ≤ 0.05) between T and C concentrations and absolute 1RM strength in stronger (squat 1RM = 150.5 kg), but not weaker (squat 1RM = 117.4 kg), men. A short window of training involving FB or SB protocols can improve strength and body composition in rugby players. The similar strength gains highlight training volume as a key adaptive stimulus, although the programme structure (i.e. FB or SB) did influence the body composition and hormonal outcomes. It also appears that 1RM strength is associated with individual hormonal changes and baseline strength. PMID:27274103

The effects of two equal-volume training protocols upon strength, body composition and salivary hormones in male rugby union players.

PubMed

Crewther, B T; Heke, Tol; Keogh, Jwl

2016-06-01

This study examined the effects of two equal-volume resistance-training protocols upon strength, body composition and salivary hormones in male rugby union players. Using a crossover design, 24 male rugby players completed a 4-week full-body (FB) and split-body (SB) training protocol of equal volume during the competitive season. One repetition maximum (1RM) strength, body composition via skinfold measurements and salivary testosterone (T) and cortisol (C) concentrations were assessed pre and post training. The FB and SB protocols improved upper (7.3% and 7.4%) and lower body 1RM strength (7.4% and 5.4%), whilst reducing body fat (-0.9% and -0.4%) and fat mass (-5.7% and -2.1%), respectively (all p ≤ 0.021). The SB protocol elevated T (21%) and C (50%) concentrations with a higher T/C ratio (28%) after FB training (all p ≤ 0.039). The strength changes were similar, but the body composition and hormonal results differed by protocol. Slope testing on the individual responses identified positive associations (p ≤ 0.05) between T and C concentrations and absolute 1RM strength in stronger (squat 1RM = 150.5 kg), but not weaker (squat 1RM = 117.4 kg), men. A short window of training involving FB or SB protocols can improve strength and body composition in rugby players. The similar strength gains highlight training volume as a key adaptive stimulus, although the programme structure (i.e. FB or SB) did influence the body composition and hormonal outcomes. It also appears that 1RM strength is associated with individual hormonal changes and baseline strength.

The Trainability of Adolescent Soccer Players to Brief Periodized Complex Training.

PubMed

Chatzinikolaou, Athanasios; Michaloglou, Konstantinos; Avloniti, Alexandra; Leontsini, Diamanda; Deli, Chariklia K; Vlachopoulos, Dimitris; Gracia-Marco, Luis; Arsenis, Sotirios; Athanailidis, Ioannis; Draganidis, Dimitrios; Jamurtas, Athanasios Z; Williams, Craig A; Fatouros, Ioannis G

2018-05-01

To investigate the effect of a complex, short-term strength/power training protocol on performance and body composition of elite early adolescent soccer players. Twenty-two players (14-15 y) were randomly assigned to (1) an experimental group (N = 12; participated in a 5-wk training protocol with traditional multijoint power resistance exercises, Olympic-style lifts, plyometric drills, and speed work; 4 times per week) or (2) a control group (N = 10). Strength and power performance (jumping, speed, change of direction, repeated sprint ability, endurance, isokinetic strength of knee flexors and extensors, maximal strength in various lifts, and speed-endurance) were evaluated pretraining and posttraining. Cessation of training for 5 weeks in the control group induced a marked performance deterioration (∼5%-20%). Training not only prevented strength performance deterioration but also increased it (∼2%-30%). Endurance and repeated sprint ability declined to a smaller extent in experimental group compared with control group (15% vs 7.5%). Isometric strength and body composition remained unaltered in both groups. Results demonstrate that (1) young players exhibit a high level of trainability of their strength/power performance (but not endurance) in response to a short-term complex training protocol during early adolescence, (2) Olympic-style lifts are characterized by increased safety in this age group and appear to be highly effective, (3) lifts incorporating a hip thrust result in increased strength of both knee extensors and flexors, (4) cessation of training for only 5 weeks results in marked deterioration of strength/power and endurance performance, and (5) improvement of strength/power performance may be related to neural-based adaptation as body composition remained unaffected.

Effects of Nintendo Wii Fit Plus training on ankle strength with functional ankle instability.

PubMed

Kim, Ki-Jong; Jun, Hyun-Ju; Heo, Myoung

2015-11-01

[Purpose] The objective of this study was to examine the effects of a training program using the Nintendo Wii Fit Plus on the ankle muscle strengths of subjects with functional ankle instability. [Subjects and Methods] This study was conducted using subjects in their 20s who had functional ankle instability. They were randomized to a strengthening training group and a balance training group with 10 subjects in each, and they performed an exercise using Nintendo Wii Fit Plus for 20 minutes. In addition, every participant completed preparation and finishing exercises for 5 minutes, respectively. [Results] The muscle strengths after conducting plantar flexion and dorsiflexion significantly increased at the angular velocities of 60° and 120° in the strengthening training group. Furthermore, the muscle strengths after conducting plantar flexion, dorsiflexion, eversion, and inversion significantly increased at the angular velocities of 60° and 120° in the balance training group. [Conclusion] The balance training group using Nintendo Wii Fit Plus showed better results than the strengthening training group. Consequently, it is recommended to add the balance training program of the Nintendo Wii Fit Plus to conventional exercise programs to improve ankle muscle strength in functional ankle instability at a low cost.

Lower-extremity resistance training on unstable surfaces improves proxies of muscle strength, power and balance in healthy older adults: a randomised control trial.

PubMed

Eckardt, Nils

2016-11-24

It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT]) on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT) and two types of URT, i.e., machine-based (M-URT) and free-weight URT (F-URT), on measures of lower-extremity muscle strength, power and balance in older adults. Seventy-five healthy community-dwelling older adults aged 65-80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength), power (e.g., chair rise test) and balance (e.g., functional reach test), carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an effective and safe alternative training program to mitigate intrinsic fall risk factors in older adults. This trial has been registered with clinicaltrials.gov ( NCT02555033 ) on 09/18/2015.

Inspiratory muscle training increases inspiratory muscle strength in patients weaning from mechanical ventilation: a systematic review.

PubMed

Moodie, Lisa; Reeve, Julie; Elkins, Mark

2011-01-01

Does inspiratory muscle training improve inspiratory muscle strength and endurance, facilitate weaning, improve survival, and reduce the rate of reintubation and tracheostomy in adults receiving mechanical ventilation? Systematic review of randomised or quasi-randomised controlled trials. Adults over 16 years of age receiving mechanical ventilation. Inspiratory muscle training versus sham or no inspiratory muscle training. Data were extracted regarding inspiratory muscle strength and endurance, the duration of unassisted breathing periods, weaning success and duration, reintubation and tracheostomy, survival, adverse effects, and length of stay. Three studies involving 150 participants were included in the review. The studies varied in time to commencement of the training, the device used, the training protocol, and the outcomes measured. Inspiratory muscle training significantly increased inspiratory muscle strength over sham or no training (weighted mean difference 8 cmH(2)O, 95% CI 6 to 9). There were no statistically significant differences between the groups in weaning success or duration, survival, reintubation, or tracheostomy. Inspiratory muscle training was found to significantly increase inspiratory muscle strength in adults undergoing mechanical ventilation. Despite data from a substantial pooled cohort, it is not yet clear whether the increase in inspiratory muscle strength leads to a shorter duration of mechanical ventilation, improved weaning success, or improved survival. Further large randomised studies are required to clarify the impact of inspiratory muscle training on patients receiving mechanical ventilation. PROSPERO CRD42011001132. Copyright © 2011 Australian Physiotherapy Association. Published by .. All rights reserved.

Randomized controlled trial of strength training in post-polio patients.

PubMed

Chan, K Ming; Amirjani, Nasim; Sumrain, Mae; Clarke, Anita; Strohschein, Fay J

2003-03-01

Many post-polio patients develop new muscle weakness decades after the initial illness. However, its mechanism and treatment are controversial. The purpose of this study was to test the hypotheses that: (1) after strength training, post-polio patients show strength improvement comparable to that seen in the healthy elderly; (2) such training does not have a deleterious effect on motor unit (MU) survival; and (3) part of the strength improvement is due to an increase in voluntary motor drive. After baseline measures including maximum voluntary contraction force, voluntary activation index, motor unit number estimate, and the tetanic tension of the thumb muscles had been determined, 10 post-polio patients with hand involvement were randomized to either the training or control group. The progressive resistance training program consisted of three sets of eight isometric contractions, three times weekly for 12 weeks. Seven healthy elderly were also randomized and trained in a similar manner. Changes in the baseline parameters were monitored once every 4 weeks throughout the training period. The trained post-polio patients showed a significant improvement in their strength (P < 0.05). The magnitude of gain was greater than that seen in the healthy elderly (mean +/- SE, 41 +/- 16% vs. 29 +/- 8%). The training did not adversely affect MU survival and the improvement was largely attributable to an increase in voluntary motor drive. We therefore conclude that moderate intensity strength training is safe and effective in post-polio patients.

Feasibility/treatability studies for removal of heavy metals from training range soils at the Grafenwoehr Training Area, Germany

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, R.W.

1995-05-01

A feasibility/treatability study was performed to investigate the leaching potential of heavy metals (particularly lead) from soils at the Grafenw6hr Training Area (GTA) in Germany. The study included an evaluation of the effectiveness of chelant extraction to remediate the heavy-metal-contarninated soils. Batch shaker tests indicated that ethylenediaminetetraacetic acid (EDTA) (0.01M) was more effective than citric acid (0.01M) at removing cadmium, copper, lead, and zinc. EDTA and citric acid were equally effective in mobilizing chromium and barium from the soil. The batch shaker technique with chelant extraction offers promise as a remediation technique for heavy-metal-contaninated soil at the GTA. Columnar floodingmore » tests conducted as part of the study revealed that deionized water was the least effective leaching solution for mobilization of the heavy metals; the maximum solubilization obtained was 3.72% for cadmium. EDTA (0.05M) achieved the greatest removal of lead (average removal of 17.6%). The difficulty of extraction using deionized water indicates that all of the heavy metals are very tightly bound to the soil; therefore, they are very stable in the GTA soils and do not pose a serious threat to the groundwater system. Columnar flooding probably does not represent a viable remediation technique for in-situ cleanup of heavy-metal-contaminated soils at the GTA.« less

Effects of remediation train sequence on decontamination of heavy metal-contaminated soil containing mercury.

PubMed

Hseu, Zeng-Yei; Huang, Yu-Tuan; Hsi, Hsing-Cheng

2014-09-01

When a contaminated site contains pollutants including both nonvolatile metals and Hg, one single remediation technology may not satisfactorily remove all contaminants. Therefore, in this study, chemical extraction and thermal treatment were combined as a remediation train to remove heavy metals, including Hg, from contaminated soil. A 0.2 M solution of ethylenediamine tetraacetic acid (EDTA) was shown to be the most effective reagent for extraction of considerable amounts of Cu, Pb, and Zn (> 50%). Hg removal was ineffective using 0.2 M EDTA, but thermogravimetric analysis suggested that heating to 550 degrees C with a heating rate of 5 degrees C/min for a duration of 1 hr appeared to be an effective approach for Hg removal. With the employment of thermal treatment, up to 99% of Hg could be removed. However executing thermal treatment prior to chemical extraction reduced the effectiveness of the subsequent EDTA extraction because nonvolatile heavy metals were immobilized in soil aggregates after the 550 degrees C treatment. The remediation train of chemical extraction followed by thermal treatment appears to remediate soils that have been contaminated by many nonvolatile heavy metals and Hg. Implications: A remediation train conjoining two or more techniques has been initialized to remove multiple metals. Better understandings of the impacts of treatment sequences, namely, which technique should be employed first on the soil properties and the decontamination efficiency, are in high demand. This study provides a strategy to remove multiple heavy metals including Hg from a contaminated soil. The interactions between thermal treatment and chemical extraction on repartitioning of heavy metals was revealed. The obtained results could offer an integrating strategy to remediate the soil contaminated with both heavy metals and volatile contaminants.

Effects of 8 Weeks’ Specific Physical Training on the Rotator Cuff Muscle Strength and Technique of Javelin Throwers

PubMed Central

Kim, Hyeyoung; Lee, Youngsun; Shin, Insik; Kim, Kitae; Moon, Jeheon

2014-01-01

[Purpose] For maximum efficiency and to prevent injury during javelin throwing, it is critical to maintain muscle balance and coordination of the rotator cuff and the glenohumeral joint. In this study, we investigated the change in the rotator cuff muscle strength, throw distance and technique of javelin throwers after they had performed a specific physical training that combined elements of weight training, function movement screen training, and core training. [Subjects] Ten javelin throwers participated in this study: six university athletes in the experimental group and four national-level athletes in the control group. [Methods] The experimental group performed 8 weeks of the specific physical training. To evaluate the effects of the training, measurements were performed before and after the training for the experimental group. Measurements comprised anthropometry, isokinetic muscle strength measurements, the function movement screen test, and movement analysis. [Results] After the specific physical training, the function movement screen score and external and internal rotator muscle strength showed statistically significant increases. Among kinematic factors, only pull distance showed improvement after training. [Conclusion] Eight weeks of specific physical training for dynamic stabilizer muscles enhanced the rotator cuff muscle strength, core stability, throw distance, and flexibility of javelin throwers. These results suggest that specific physical training can be useful for preventing shoulder injuries and improving the performance for javelin throwers. PMID:25364111

Effects of 8 weeks' specific physical training on the rotator cuff muscle strength and technique of javelin throwers.

PubMed

Kim, Hyeyoung; Lee, Youngsun; Shin, Insik; Kim, Kitae; Moon, Jeheon

2014-10-01

[Purpose] For maximum efficiency and to prevent injury during javelin throwing, it is critical to maintain muscle balance and coordination of the rotator cuff and the glenohumeral joint. In this study, we investigated the change in the rotator cuff muscle strength, throw distance and technique of javelin throwers after they had performed a specific physical training that combined elements of weight training, function movement screen training, and core training. [Subjects] Ten javelin throwers participated in this study: six university athletes in the experimental group and four national-level athletes in the control group. [Methods] The experimental group performed 8 weeks of the specific physical training. To evaluate the effects of the training, measurements were performed before and after the training for the experimental group. Measurements comprised anthropometry, isokinetic muscle strength measurements, the function movement screen test, and movement analysis. [Results] After the specific physical training, the function movement screen score and external and internal rotator muscle strength showed statistically significant increases. Among kinematic factors, only pull distance showed improvement after training. [Conclusion] Eight weeks of specific physical training for dynamic stabilizer muscles enhanced the rotator cuff muscle strength, core stability, throw distance, and flexibility of javelin throwers. These results suggest that specific physical training can be useful for preventing shoulder injuries and improving the performance for javelin throwers.

CNTF 1357 G -> A polymorphism and the muscle strength response to resistance training.

PubMed

Walsh, Sean; Kelsey, Bethany K; Angelopoulos, Theodore J; Clarkson, Priscilla M; Gordon, Paul M; Moyna, Niall M; Visich, Paul S; Zoeller, Robert F; Seip, Richard L; Bilbie, Steve; Thompson, Paul D; Hoffman, Eric P; Price, Thomas B; Devaney, Joseph M; Pescatello, Linda S

2009-10-01

The present study examined associations between the ciliary neurotrophic factor (CNTF) 1357 G --> A polymorphism and the muscle strength response to a unilateral, upper arm resistance-training (RT) program among healthy, young adults. Subjects were 754 Caucasian men (40%) and women (60%) who were genotyped and performed a training program of the nondominant (trained) arm with the dominant (untrained) arm as a comparison. Peak elbow flexor strength was measured with one repetition maximum, isometric strength with maximum voluntary contraction, and bicep cross-sectional area with MRI in the trained and untrained arms before and after training. Women with the CNTF GG genotype gained more absolute isometric strength, as measured by MVC (6.5 +/- 0.3 vs. 5.2 +/- 0.5 kg), than carriers of the CNTF A1357 allele in the trained arm pre- to posttraining (P < 0.05). No significant associations were seen in men. Women with the CNTF GG genotype gained more absolute dynamic (1.0 +/- 0.1 vs. 0.6 +/- 0.1 kg) and allometric (0.022 +/- 0.0 vs. 0.015 +/- 0.0 kg/kg(-0.67)) strength, as measured by 1 RM, than carriers of the CNTF A1357 allele in the untrained arm pre- to posttraining (P < 0.05). No significant associations were seen in men. No significant associations, as measured by cross-sectional area, were seen in men or women. The CNTF 1357 G --> A polymorphism explains only a small portion of the variability in the muscle strength response to training in women.

Effects of rest interval on isokinetic strength and functional performance after short-term high intensity training.

PubMed

Pincivero, D M; Lephart, S M; Karunakara, R G

1997-09-01

The ability to maximally generate active muscle tension during resistance training has been established to be a primary determinant for strength development. The influence of intrasession rest intervals may have a profound effect on strength gains subsequent to short-term high intensity training. The purpose of this study was to examine the effects of rest interval on strength and functional performance after four weeks of isokinetic training. Fifteen healthy college aged individuals were randomly assigned to either a short rest interval group (group 1, n = 8) or a long rest interval group (group 2, n = 7). Subjects were evaluated for quadriceps and hamstring isokinetic strength at 60 (five repetitions) and 180 (30 repetitions) degrees/second and functional performance with the single leg hop for distance test. One leg of each subject was randomly assigned to a four week, three days/week isokinetic strength training programme for concentric knee extension and flexion performed at 90 degrees/second. Subjects in group 1 received a 40 second rest interval in between exercise sets, whereas subjects in group 2 received a 160 second rest period. A two factor analysis of variance for the pre-test--post-test gain scores (%) showed significantly greater improvements for isokinetic hamstring total work and average power at 180 degrees/second for the trained limb of subjects in group 2 than their contralateral non-trained limb and the subjects in group 1. Significantly greater improvements for the single leg hop for distance were also found for the trained limbs of subjects in both groups as compared with the non-trained limbs. The findings indicate that a relatively longer intrasession rest period resulted in a greater improvement in hamstring muscle strength during short term high intensity training.

Effects of resistance training, detraining, and retraining on strength and functional capacity in elderly.

PubMed

Sakugawa, Raphael Luiz; Moura, Bruno Monteiro; Orssatto, Lucas Bet da Rosa; Bezerra, Ewertton de Souza; Cadore, Eduardo Lusa; Diefenthaeler, Fernando

2018-05-17

The interruption of training (detraining) results in loss of the gains acquired. Partial retention could occur after detraining, and variation in training stimuli may optimize retraining adaptations. To evaluate the effect of a resistance-retraining program on strength and functional capacity performance after a detraining period. Ten elderly men and women (63-68 years) completed 12 weeks of training, 16 weeks of detraining, and 8 weeks of retraining. One-repetition maximum (1-RM) at 45° leg press, maximum isometric knee extension torque, rate of torque development (RTD), 30-s sit-to-stand, timed up and go, and stair ascent and descent tests were assessed. The 1-RM increased after training (p < 0.01) and remained higher after a detraining period when compared to pre-training (p < 0.01). Post-retraining values were not different from post-training period (p > 0.05). For RTD and 30-s sit-to-stand, there was an increase after retraining when compared to pre-training values (p < 0.05). For timed up and go and stair ascent and descent, reductions were observed between pre-training and post-training periods (p < 0.05), only timed up and go increased after the detraining period (p < 0.01). After 16 weeks of detraining, the maximum strength did not return to baseline levels, and a retraining with explosive strength exercise sessions can recover maximum strength gains, RTD, and functional capacity at the same level obtained after a detraining period. The inclusion of an explosive strength session in retraining period improves RTD and 30-s sit-to-stand performance and can accelerate the recovery of strength after a detraining period.

Short-Term Training Cessation as a Method of Tapering to Improve Maximal Strength.

PubMed

Pritchard, Hayden J; Barnes, Matthew J; Stewart, Robin J C; Keogh, Justin W L; McGuigan, Michael R

2018-02-01

Pritchard, HJ, Barnes, MJ, Stewart, RJC, Keogh, JWL, and McGuigan, MR. Short-term training cessation as a method of tapering to improve maximal strength. J Strength Cond Res 32(2): 458-465, 2018-The aim of this study was to determine the effects of 2 different durations of training cessation on upper- and lower-body maximal strength performance and to investigate the mechanisms underlying performance changes following short-term training cessation. Eight resistance trained males (23.8 ± 5.4 years, 79.6 ± 10.2 kg, 1.80 ± 0.06 m, relative deadlift 1 repetition maximum of 1.90 ± 0.30 times bodyweight [BW]) each completed two 4-week strength training periods followed by either 3.5 days (3.68 ± 0.12 days) or 5.5 days (5.71 ± 0.13 days) of training cessation. Testing occurred pretraining (T1), on the final day of training (T2), and after each respective period of training cessation (T3). Participants were tested for salivary testosterone and cortisol, plasma creatine kinase, psychological profiles, and performance tests (countermovement jump [CMJ], isometric midthigh pull, and isometric bench press [IBP]) on a force plate. Participants' BW increased significantly over time (p = 0.022). The CMJ height and IBP peak force showed significant increases over time (p = 0.013, 0.048, and 0.004, respectively). Post hoc testing showed a significant increase between T1 and T3 for both CMJ height and IBP peak force (p = 0.022 and 0.008 with effect sizes of 0.30 and 0.21, respectively). No other significant differences were seen for any other measures. These results suggest that a short period of strength training cessation can have positive effects on maximal strength expression, perhaps because of decreases in neuromuscular fatigue.

Heavy Equipment Operation Curriculum for Grades 11-12.

ERIC Educational Resources Information Center

Gubbins Associates, Hadlyme, CT.

This curriculum for the training of students in grades 11 and 12 is intended to provide a program of instruction in the operation and maintenance of heavy equipment for construction work and farms. It is also suitable for the training of adult learners interested in upgrading their skills or improving their opportunities to enter this labor…

Heavy Equipment Technician: Apprenticeship Course Outline. Apprenticeship and Industry Training. 1912

ERIC Educational Resources Information Center

Alberta Advanced Education and Technology, 2012

2012-01-01

The graduate of the Heavy Equipment Technician apprenticeship program is a certified journeyperson who will be able to: (1) diagnose repair, and maintain by skills and knowledge gained through training and experience any of the working parts of diesel engines as well as the various components of mobile industrial equipment; (2) use, competently,…

The acute effects of heavy back squats on mechanical variables during a series of bilateral hops.

PubMed

Moir, Gavin L; Dale, Jonathan R; Dietrich, Wendy W

2009-07-01

The purpose of the present study was to investigate the acute effects of performing a heavy resistance exercise (HRE) protocol on the mechanical variables during a series of bilateral hops. In a block-randomized design, 10 strength trained men performed an HRE or a control treatment before performing 5 series of bilateral hops separated by 2 minutes of passive recovery. Each series of bilateral hops was performed for 15 seconds on a force platform with the subject hopping at a frequency of 2.0 Hz. From the vertical force trace, the vertical force during the countermovement phase of each hop, the negative displacement during the countermovement phase, and the vertical stiffness were calculated. The HRE treatment consisted of performing parallel back squats with 40, 50, 60, and 80% of each subject's 1-repetition maximum after a series of dynamic stretches. The control treatment consisted of the dynamic stretches only. No significant differences in any of the mechanical variables were reported after the 2 treatments (p > 0.05). There were no significant correlations between the absolute maximal strength values and the percent change in any of the mechanical variables after the 2 treatments. Despite the lack of significant changes reported for the group, there were some notable individual responses. It is possible that increases in vertical stiffness during bilateral hops can be achieved after an HRE protocol in certain individuals. However, practitioners should be aware of the specificity issues and the individual nature of the responses to such protocols.

[Case-control study on the effect of core strength training on the function of anterior cruciate ligament reconstruction].

PubMed

Wu, Bin; Zheng, Song; Cai, Zhen-Hai; Wang, Yue-Li; Zeng, Ming

2017-08-25

To observe the effect of core strength training on knee joint function and postural stability after anterior cruciate ligament reconstruction (ACLR). A total of 80 ACLR patients were randomly allocated into conventional rehabilitation training group and core strength training group from May 2013 to May 2015 with 40 patients in each group. The patients in conventional rehabilitation training group underwent conventional ACLR rehabilitation training, in which 28 males and 12 females. The mean age was(30.5±5.2) years old(ranged, 22 to 42 years old). The mean BMI was(23.8±2.4) kg/m²(ranged, 18.2 to 25.9 kg/m²). Thirty patients had injuries on the dominant side and 10 patients had injuries on the non-dominant side. The core strength training group received conventional ACLR rehabilitation training and core strength training, in which 31 males and 9 females. The mean age was(31.1±4.8) years old(ranged, 21 to 45 years old). The mean BMI was(24.1±2.7) kg/m²(ranged, 18.5 to 26.1 kg/m²) . Twenty-seven patients had injuries on the dominant side and 13 patients had injuries on the non-dominant side. The Lysholm score, tibial anterior transition measured by KT-1000 before and after treatment, and the Star Excursion Balance Test results after treatment were compared between the two groups. Six months after rehabilitation training, the tibial anterior transition of the conventional rehabilitation training group and the core strength training group were(3.4±1.0) mm and(3.3±1.2) mm respectively, which were less than(12.1±1.8) mm and(12.5±2.0) mm before treatment. But there was no significant difference in anterior tibial translation between two groups( P >0.05). The Lysholm score of the conventional rehabilitation training group and the core strength training group were 91.8±4.3 and 92.1±3.9 individually, which were higher than 69.2±5.8 and 70.2±5.1 before treatment. But there was no significant difference in Lysholm score between two groups( P >0.05). Six months after rehabilitation training, the results of Star Excursion Balance Test showed the reach distance with the support in the injured side and healthy side in the core strength training group were greater than that of the conventional rehabilitation training group in the eight directions( P <0.05). The core strength training could improve the dynamic balance of ACLR patients.

[Effects of education and strength training on functional tests among older people with osteoarthritis].

PubMed

Jiménez S, Christian Edgardo; Fernández G, Rubén; Zurita O, Félix; Linares G, Daniel; Farías M, Ariel

2014-04-01

Hip and knee osteoarthritis are important causes of pain and disability among older people. Education and strength training can alleviate symptoms and avoid functional deterioration. To assess muscle strength, fall risk and quality of life of older people with osteoarthritis and the effects of physiotherapy education and strength training on these variables. Thirty participants aged 78 ± 5 years (63% women) were randomly assigned to receive physiotherapy (Controls), physiotherapy plus education (Group 1) and physiotherapy plus strength training (group 2). At baseline and after 16 weeks of intervention, patients were evaluated with the Senior Fitness Test, Timed Up and Go and Quality of Life score short form (SF-36). During the intervention period, Senior Fitness Test and Timed Up and Go scores improved in all groups and SF-36 did not change. The improvement in Senior Fitness Test and Timed Up and Go was more marked in Groups 1 and 2 than in the control group. Education and strength training improve functional tests among older people with osteoarthritis.

Strength training for a child with suspected developmental coordination disorder.

PubMed

Menz, Stacy M; Hatten, Kristin; Grant-Beuttler, Marybeth

2013-01-01

Children with developmental coordination disorder (DCD) demonstrate difficulty with feedforward motor control and use varied compensatory strategies. To examine gross motor function changes following strength training in a child with motor control difficulties. A girl aged 6 years 11 months, with apraxia and hypotonia, and demonstrating motor delays consistent with DCD. Twenty-four strength training sessions were completed using a universal exercise unit. Postintervention scores significantly improved on the Bruininks-Oseretsky test of motor proficiency, second edition, and the Canadian occupational performance measure scores and raised the developmental coordination disorder questionnaire, revised 2007, scores above the range where DCD is suspected. Nonsignificant changes in strength were observed. Improved function and significant gains in manual coordination were observed following blocked practice of isolated, simple joint movements during strength training. Improved motor skills may be because of effective use of feedforward control and improved stabilization. Strength training does not rehearse skills using momentum, explaining nonsignificant changes in locomotor or locomotion areas.

Ground vibrations from heavy freight trains

NASA Astrophysics Data System (ADS)

Dawn, T. M.

1983-03-01

Ground vibration from heavy freight trains on good quality welded track are found to have only a weak dependence on train speed above 30 km/h. At the site on which these tests were carried out a critical speed was found at which the vibration reached a peak. The frequencies of vibration produced appear to be functions of track and vehicle dimensions and the critical speed occurs at the coincidence of sleeper passage frequency and the total vehicle on track resonance frequency.

Effects of a Six-Week Strength Training Programme on Change of Direction Performance in Youth Team Sport Athletes

PubMed Central

Bourgeois, Frank A.; Gamble, Paul; Gill, Nic D.; McGuigan, Mike R.

2017-01-01

This study investigated the effects of eccentric phase-emphasis strength training (EPE) on unilateral strength and performance in 180- and 45-degree change of direction (COD) tasks in rugby union players. A 12-week cross-over design was used to compare the efficacy of resistance training executed with 3 s eccentric duration (EPE, n = 12) against conventional strength training, with no constraints on tempo (CON, n = 6). Players in each condition were categorised as ‘fast’ (FAST) or ‘slow’ (SLOW) using median trial times from baseline testing. Players recorded greater isometric strength improvements following EPE (ES = −0.54 to 1.80). Whilst these changes were not immediate, players improved in strength following cessation. Improvements in 180-degree COD performance was recorded at all test-points following EPE (ES = −1.32 to −0.15). Improvements in 45-degree COD performance were apparent for FAST following CON (ES = −0.96 to 0.10), but CON was deleterious for SLOW (ES = −0.60 to 1.53). Eccentric phase-emphasis strength training shows potential for sustained strength enhancement. Positive performance changes in COD tasks were category- and condition-specific. The data indicate the greatest improvement occurred at nine weeks following resistance training in these players. Performance benefits may also be specific to COD task, player category, and relative to emphasis on eccentric phase activity. PMID:29910443

A high protein diet (3.4 g/kg/d) combined with a heavy resistance training program improves body composition in healthy trained men and women--a follow-up investigation.

PubMed

Antonio, Jose; Ellerbroek, Anya; Silver, Tobin; Orris, Steve; Scheiner, Max; Gonzalez, Adriana; Peacock, Corey A

2015-01-01

The consumption of a high protein diet (>4 g/kg/d) in trained men and women who did not alter their exercise program has been previously shown to have no significant effect on body composition. Thus, the purpose of this investigation was to determine if a high protein diet in conjunction with a periodized heavy resistance training program would affect indices of body composition, performance and health. Forty-eight healthy resistance-trained men and women completed this study (mean ± SD; Normal Protein group [NP n = 17, four female and 13 male]: 24.8 ± 6.9 yr; 174.0 ± 9.5 cm height; 74.7 ± 9.6 kg body weight; 2.4 ± 1.7 yr of training; High Protein group [HP n = 31, seven female and 24 male]: 22.9 ± 3.1 yr; 172.3 ± 7.7 cm; 74.3 ± 12.4 kg; 4.9 ± 4.1 yr of training). Moreover, all subjects participated in a split-routine, periodized heavy resistance-training program. Training and daily diet logs were kept by each subject. Subjects in the NP and HP groups were instructed to consume their baseline (~2 g/kg/d) and >3 g/kg/d of dietary protein, respectively. Subjects in the NP and HP groups consumed 2.3 and 3.4 g/kg/day of dietary protein during the treatment period. The NP group consumed significantly (p < 0.05) more protein during the treatment period compared to their baseline intake. The HP group consumed more (p < 0.05) total energy and protein during the treatment period compared to their baseline intake. Furthermore, the HP group consumed significantly more (p < 0.05) total calories and protein compared to the NP group. There were significant time by group (p ≤ 0.05) changes in body weight (change: +1.3 ± 1.3 kg NP, -0.1 ± 2.5 HP), fat mass (change: -0.3 ± 2.2 kg NP, -1.7 ± 2.3 HP), and % body fat (change: -0.7 ± 2.8 NP, -2.4 ± 2.9 HP). The NP group gained significantly more body weight than the HP group; however, the HP group experienced a greater decrease in fat mass and % body fat. There was a significant time effect for FFM; however, there was a non-significant time by group effect for FFM (change: +1.5 ± 1.8 NP, +1.5 ± 2.2 HP). Furthermore, a significant time effect (p ≤ 0.05) was seen in both groups vis a vis improvements in maximal strength (i.e., 1-RM squat and bench) vertical jump and pull-ups; however, there were no significant time by group effects (p ≥ 0.05) for all exercise performance measures. Additionally, there were no changes in any of the blood parameters (i.e., basic metabolic panel). Consuming a high protein diet (3.4 g/kg/d) in conjunction with a heavy resistance-training program may confer benefits with regards to body composition. Furthermore, there is no evidence that consuming a high protein diet has any deleterious effects.

Virtual Proprioception for eccentric training.

PubMed

LeMoyne, Robert; Mastroianni, Timothy

2017-07-01

Wireless inertial sensors enable quantified feedback, which can be applied to evaluate the efficacy of therapy and rehabilitation. In particular eccentric training promotes a beneficial rehabilitation and strength training strategy. Virtual Proprioception for eccentric training applies real-time feedback from a wireless gyroscope platform enabled through a software application for a smartphone. Virtual Proprioception for eccentric training is applied to the eccentric phase of a biceps brachii strength training and contrasted to a biceps brachii strength training scenario without feedback. During the operation of Virtual Proprioception for eccentric training the intent is to not exceed a prescribed gyroscope signal threshold based on the real-time presentation of the gyroscope signal, in order to promote the eccentric aspect of the strength training endeavor. The experimental trial data is transmitted wireless through connectivity to the Internet as an email attachment for remote post-processing. A feature set is derived from the gyroscope signal for machine learning classification of the two scenarios of Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback. Considerable classification accuracy is achieved through the application of a multilayer perceptron neural network for distinguishing between the Virtual Proprioception real-time feedback for eccentric training and eccentric training without feedback.

The Effects of a Non-Traditional Strength Training Program on the Health-Related Fitness Outcomes of Youth Strength Training Participants

ERIC Educational Resources Information Center

Cowan, Wendy; Foster, Byron

2009-01-01

The purpose of this study was to determine the extent to which a non-traditional strength training program will impact the health-related fitness of youth. Researchers hypothesized that the strengthening program would positively affect the fitness outcomes. Participant physical education classes incorporated strengthening exercises three days…

Strongwomen® Program Evaluation: Effect of Strength Training Exercises on Physical Fitness of Participants

ERIC Educational Resources Information Center

Chaudhary, Anil Kumar; Van Horn, Beth; Corbin, Marilyn

2015-01-01

The Strongwomen® Program (SWP) is a nationally disseminated group strength-training exercise and nutrition education program delivered by Extension. The study reported here examined the effect of strength training exercises in SWP on improvement in physical fitness of program participants. Senior Fitness Test was used to collect data. Upon…

The effect of inspiratory and expiratory respiratory muscle training in rowers.

PubMed

Forbes, S; Game, A; Syrotuik, D; Jones, R; Bell, G J

2011-10-01

This study examined inspiratory and expiratory resistive loading combined with strength and endurance training on pulmonary function and rowing performance. Twenty-one male (n = 9) and female (n = 12) rowers were matched on 2000 m simulated rowing race time and gender and randomly assigned to two groups. The experimental group trained respiratory muscles using a device that provided both an inspiratory and expiratory resistance while the control group used a SHAM device. Respiratory muscle training (RMT) or SHAM was performed 6 d/wk concurrent with strength (3 d/wk) and endurance (3 d/wk) training on alternate days for 10 weeks. Respiratory muscle training (RMT) enhanced maximum inspiratory (PI(max)) and expiratory (PE(max)) strength at rest and during recovery from exercise (P < 0.05). Both groups showed improvements in peak VO2, strength, and 2000 m performance time (P < 0.05). It was concluded that RMT is effective for improving respiratory strength but did not facilitate greater improvements to simulated 2000 m rowing performance.

10-year changes in upper body strength and power in elite professional rugby league players--the effect of training age, stage, and content.

PubMed

Baker, Daniel G

2013-02-01

The purpose of this investigation was to observe changes in maximal upper body strength and power across a 10-year period in professional athletes who were experienced resistance trainers. Six professional rugby league players were observed with test data reported according to 2 important training stages in their professional careers. The first stage (1996-1998) monitored the changes as the subjects strived to establish themselves as elite professionals in their sport. The remaining test data are from the latter stage (2000-2006), which is characterized by a longer competition schedule and shorter periods devoted to improving physical preparation. The changes in upper body strength, assessed by the 1 repetition maximum bench press and mean maximum power during bench press throws with various barbell resistances of 40-80 kg, were assessed by effect size (ES) and smallest worthwhile change (SWC) statistics. Large increases in strength and power of approximately 22-23% were reported across the 10-year period, however, only small changes (as determined by ES) in strength or power occurred after year 2000 till 2006. This result of only small changes in strength or power despite 6 years of intense resistance training was attributed to 3 main factors. Key among them are the possible existence of a "strength ceiling" for experienced resistance trainers, the Long-term Athlete Development model, and possibly an inappropriate volume of strength-endurance training from 2004 to 2005. The fact that an SWC in strength and power occurred in the year after the cessation of strength-endurance training suggests that training program manipulation is still an influencing factor in continuing strength and power gains in experienced resistance trainers.

Comparison between linear and daily undulating periodized resistance training to increase strength.

PubMed

Prestes, Jonato; Frollini, Anelena B; de Lima, Cristiane; Donatto, Felipe F; Foschini, Denis; de Cássia Marqueti, Rita; Figueira, Aylton; Fleck, Steven J

2009-12-01

To determine the most effective periodization model for strength and hypertrophy is an important step for strength and conditioning professionals. The aim of this study was to compare the effects of linear (LP) and daily undulating periodized (DUP) resistance training on body composition and maximal strength levels. Forty men aged 21.5 +/- 8.3 and with a minimum 1-year strength training experience were assigned to an LP (n = 20) or DUP group (n = 20). Subjects were tested for maximal strength in bench press, leg press 45 degrees, and arm curl (1 repetition maximum [RM]) at baseline (T1), after 8 weeks (T2), and after 12 weeks of training (T3). Increases of 18.2 and 25.08% in bench press 1 RM were observed for LP and DUP groups in T3 compared with T1, respectively (p < or = 0.05). In leg press 45 degrees , LP group exhibited an increase of 24.71% and DUP of 40.61% at T3 compared with T1. Additionally, DUP showed an increase of 12.23% at T2 compared with T1 and 25.48% at T3 compared with T2. For the arm curl exercise, LP group increased 14.15% and DUP 23.53% at T3 when compared with T1. An increase of 20% was also found at T2 when compared with T1, for DUP. Although the DUP group increased strength the most in all exercises, no statistical differences were found between groups. In conclusion, undulating periodized strength training induced higher increases in maximal strength than the linear model in strength-trained men. For maximizing strength increases, daily intensity and volume variations were more effective than weekly variations.

Physical Therapist Students' Perceptions from Performing Strength and Conditioning Training: Academic, Professional, and Clinical Benefits.

PubMed

Meiners, Kelly M; Wisdom, Christina M

2017-01-01

The purpose of this qualitative study was to assess the perceptions of Doctor of Physical Therapy (DPT) students in performing collegiate athletes' strength and conditioning training. Four DPT students with the Certified Strength and Conditioning Specialist (CSCS) credential voluntarily provided collegiate athletes strength and conditioning training. Students were interviewed to obtain their perceptions of how the experience impacted performance in DPT school and perceptions of anticipated future benefits. Seven themes emerged from interviews: improved communication skills, movement analysis experience, improved time management/organization, increased understanding of exercises, attention to psychosocial aspects, interprofessional experience, and improved performance in coursework. DPT students with the CSCS credential perceived benefits from performing strength and conditioning training outside the standard DPT curriculum.

Kinetic Determinants of Reactive Strength in Highly Trained Sprint Athletes.

PubMed

Douglas, Jamie; Pearson, Simon; Ross, Angus; McGuigan, Mike

2018-06-01

Douglas, J, Pearson, S, Ross, A, and McGuigan, M. Kinetic determinants of reactive strength in highly trained sprint athletes. J Strength Cond Res 32(6): 1562-1570, 2018-The purpose of this study was to determine the braking and propulsive phase kinetic variables underpinning reactive strength in highly trained sprint athletes in comparison with a nonsprint-trained control group. Twelve highly trained sprint athletes and 12 nonsprint-trained participants performed drop jumps (DJs) from 0.25, 0.50, and 0.75 m onto a force plate. One familiarization session was followed by an experimental testing session within the same week. Reactive strength index (RSI), contact time, flight time, and leg stiffness were determined. Kinetic variables including force, power, and impulse were assessed within the braking and propulsive phases. Sprint-trained athletes demonstrated higher RSI vs. nonsprint-trained participants across all drop heights {3.02 vs. 2.02; ES (±90% confidence limit [CL]): 3.11 ± 0.86}. This difference was primarily attained by briefer contact times (0.16 vs. 0.22 seconds; effect size [ES]: -1.49 ± 0.53) with smaller differences observed for flight time (0.50 vs. 0.46 seconds; ES: 0.53 ± 0.58). Leg stiffness, braking and propulsive phase force, and power were higher in sprint-trained athletes. Very large differences were observed in mean braking force (51 vs. 38 N·kg; ES: 2.57 ± 0.73) which was closely associated with contact time (r ±90% CL: -0.93 ± 0.05). Sprint-trained athletes exhibited superior reactive strength than nonsprint-trained participants. This was due to the ability to strike the ground with a stiffer leg spring, an enhanced expression of braking force, and possibly an increased utilization of elastic structures. The DJ kinetic analysis provides additional insight into the determinants of reactive strength which may inform subsequent testing and training.

Effects of Strength Training on Running Economy in Highly Trained Runners: A Systematic Review With Meta-Analysis of Controlled Trials.

PubMed

Balsalobre-Fernández, Carlos; Santos-Concejero, Jordan; Grivas, Gerasimos V

2016-08-01

Balsalobre-Fernández, C, Santos-Concejero, J, and Grivas, GV. Effects of strength training on running economy in highly trained runners: a systematic review with meta-analysis of controlled trials. J Strength Cond Res 30(8): 2361-2368, 2016-The purpose of this study was to perform a systematic review and meta-analysis of controlled trials to determine the effect of strength training programs on the running economy (RE) of high-level middle- and long-distance runners. Four electronic databases were searched in September 2015 (PubMed, SPORTDiscus, MEDLINE, and CINAHL) for original research articles. After analyzing 699 resultant original articles, studies were included if the following criteria were met: (a) participants were competitive middle- or long-distance runners; (b) participants had a V[Combining Dot Above]O2max >60 ml·kg·min; (c) studies were controlled trials published in peer-reviewed journals; (d) studies analyzed the effects of strength training programs with a duration greater than 4 weeks; and (e) RE was measured before and after the strength training intervention. Five studies met the inclusion criteria, resulting in a total sample size of 93 competitive, high-level middle- and long-distance runners. Four of the 5 included studies used low to moderate training intensities (40-70% one repetition maximum), and all of them used low to moderate training volume (2-4 resistance lower-body exercises plus up to 200 jumps and 5-10 short sprints) 2-3 times per week for 8-12 weeks. The meta-analyzed effect of strength training programs on RE in high-level middle- and long-distance runners showed a large, beneficial effect (standardized mean difference [95% confidence interval] = -1.42 [-2.23 to -0.60]). In conclusion, a strength training program including low to high intensity resistance exercises and plyometric exercises performed 2-3 times per week for 8-12 weeks is an appropriate strategy to improve RE in highly trained middle- and long-distance runners.

Effect of High-Speed Strength Training on Physical Performance in Young Soccer Players of Different Ages.

PubMed

Rodríguez-Rosell, David; Franco-Márquez, Felipe; Mora-Custodio, Ricardo; González-Badillo, Juan José

2017-09-01

Rodríguez-Rosell, D, Franco-Márquez, F, Mora-Custodio, R, and González-Badillo, JJ. Effect of high-speed strength training on physical performance in young soccer players of different ages. J Strength Cond Res 31(9): 2498-2508, 2017-The aim of the present study was to compare the effectiveness of low-load, low-volume weight training combined with plyometrics on strength, sprint, and jump performance in soccer players of different ages. Eighty-six soccer players from the same academy were categorized into 3 groups by age (under 13 years, U13, n = 30; under 15, U15, n = 28; and under 17, U17, n = 28) and then randomly assigned into 2 subgroups: a strength training group (STG) and a control group (CG). The strength training program was performed twice a week for 6 weeks and consisted of full squats (load: 45-60% 1 repetition maximum; volume: 3 set of 8-4 repetitions), jumps, and straight line sprint exercises. After training intervention, the STGs showed significant improvements in maximal strength (7.5-54.5%; p < 0.001), jump height (5.7-12.5%; p <0.01-0.001), and sprint time (-3.7 to -1.2%; p ≤0.05-0.001), whereas no significant gains were found for any variable in the CGs. Comparison between experimental groups resulted in a greater magnitude of change for U13 compared with U15 (effect sizes [ES]: 0.10-0.53) and U17 (ES: 0.14-1.41) soccer players in most variables, whereas U15 showed higher improvements in jump and strength parameters than U17 (ES: 0.25-0.90) soccer players. Thus, although our results indicates that a combined weight training and plyometrics program may be effective in eliciting gains in strength, jump, and sprint in soccer players of different ages, the training program used appears to be generally less effective as the age of the soccer players increased. Therefore, it appears that training characteristics (mainly volume, intensity, and type of exercise) should be modified in relation to maturity status and initial strength level.

Chronic effect of static stretching on strength performance and basal serum IGF-1 levels.

PubMed

Borges Bastos, Carmen L; Miranda, Humberto; Vale, Rodrigo Gomes de Souza; Portal, Maria de Nazaré; Gomes, M Thiago; Novaes, Jefferson da Silva; Winchester, Jason B

2013-09-01

Improving the process of how physical performance is enhanced is one of the main topics evaluated by physiologists. This process often involves athletes and nonathletic populations. The purpose of this study was to assess the chronic response to 10 weeks of static stretching exercises carried out before and during a strength training program for 8 exercises on an 8 repetition maximum (8RM) test performance, and basal serum insulinlike growth factor (IGF-1) levels. Thirty recreationally trained volunteers were randomly assigned to 1 of 3 training groups: (a) SBST (performed a warm-up with a static stretching protocol before each strength training session); (b) SDST (before each training set, a static stretching exercise was performed); and (c) OST (entire session was performed without any type of stretching exercise). Strength and IGF-1 levels were collected at the beginning (pretest) and end (posttest) of the entire experimental procedure. All the exercises showed a significant increase in muscle strength for the OST group. However, the results revealed a significant increase in the muscle strength for only a few exercises in the SBST (LP, LE) and SDST (LP) experimental conditions. Significant statistical differences were found between SBST and SDST for all the exercises in the OST experimental condition. Furthermore, the IGF-1 expression showed no significant differences in the intragroup analysis. However, the OST group showed higher values (p < 0.05) in the posttest when compared with those of the other groups (increased significantly only in the OST experimental condition). It has been concluded that, although all the groups showed an increase in muscular strength, the strength training performed without any type of stretching exercise, regardless of whether the stretching is performed before or during the lifting session, can more effectively increase muscle strength and basal serum IGF-1 levels. It was concluded that strength training, with or without the use of stretching exercises, increased muscular strength in the studied groups, and can induce an increase in IGF-1 levels.

Strength Training for Women as a Vehicle for Health Promotion at Work.

PubMed

Nestler, Kai; Witzki, Alexander; Rohde, Ulrich; Rüther, Thomas; Tofaute, Kim Alexander; Leyk, Dieter

2017-06-30

Women, on average, have less muscle strength than men. This anthropometric-physiological trait may make them more vulnerable to ex - cessive physical strain, injury, and inability to work. Strength training is used for preventive health maintenance and to lessen musculoskeletal symptoms. In this context, we studied whether the degree of muscle strength has any effect on women's health in everyday working life, and also the effects of strength training for women on their health in the workplace. We systematically searched the PubMed/MEDLINE, Embase, CINAHL, Web of Science, CENTRAL, and SPOLIT databases for pertinent publications, in accordance with the PRISMA criteria for literature searches. We analyzed all of the retrieved randomized controlled trials conducted on women aged 18 to 65 to determine the effects of training on muscle strength, physical performance ability, and health-related parameters including body composition, musculo - skeletal pain, and subjective well-being. We did not find any studies that provided answers to the first question. As for the second question, the selection criteria were met by 12 of the 4969 retrieved studies, which dealt with the effect of strength training on health in the occupational environment and involved a total of 1365 female subjects. These studies were carried out in heterogeneous subject groups, with a variety of overlapping interventions consisting of both strength and endurance training. Significantly increased strength was found in all studies, as was a reduction of pain in all of the studies where this question was asked. Inconsistent results were obtained with respect to body weight, body composition, and subjective well-being. The interventions that were conducted in these studies succeeded in increasing strength and reducing pain, even when the training was brief and of low intensity. This was true not only for women working in occupations requiring unusual physical strength, but also for those in sedentary occupations. The small number of studies performed on this subject to date is surprising in view of the high prevalence of musculoskeletal symptoms in women.

Effects of Different Types of Exercise on Body Composition, Muscle Strength, and IGF-1 in the Elderly with Sarcopenic Obesity.

PubMed

Chen, Hung-Ting; Chung, Yu-Chun; Chen, Yu-Jen; Ho, Sung-Yen; Wu, Huey-June

2017-04-01

To investigate the influence of resistance training (RT), aerobic training (AT), or combination training (CT) interventions on the body composition, muscle strength performance, and insulin-like growth factor 1 (IGF-1) of patients with sarcopenic obesity. Randomized controlled trial. Community center and research center. Sixty men and women aged 65-75 with sarcopenic obesity. Participants were randomly assigned to RT, AT, CT, and control (CON) groups. After training twice a week for 8 weeks, the participants in each group ceased training for 4 weeks before being examined for the retention effects of the training interventions. The body composition, grip strength, maximum back extensor strength, maximum knee extensor muscle strength, and blood IGF-1 concentration were measured. The skeletal muscle mass (SMM), body fat mass, appendicular SMM/weight %, and visceral fat area (VFA) of the RT, AT, and CT groups were significantly superior to those of the CON group at both week 8 and week 12. Regarding muscle strength performance, the RT group exhibited greater grip strength at weeks 8 and 12 as well as higher knee extensor performance at week 8 than that of the other groups. At week 8, the serum IGF-1 concentration of the RT group was higher than the CON group, whereas the CT group was superior to the AT and CON groups. Older adults with sarcopenic obesity who engaged in the RT, AT, and CT interventions demonstrated increased muscle mass and reduced total fat mass and VFA compared with those without training. The muscle strength performance and serum IGF-1 level in trained groups, especially in the RT group, were superior to the control group. © 2017, Copyright the Authors Journal compilation © 2017, The American Geriatrics Society.

Effect of compensatory acceleration training in combination with accommodating resistance on upper body strength in collegiate athletes

PubMed Central

Jones, Margaret T

2014-01-01

Purpose To determine the impact of inclusion of a band or chain compensatory acceleration training (CAT), in a 5-week training phase, on maximal upper body strength during a 14-week off-season strength and conditioning program for collegiate male athletes. Patients and methods Twenty-four National Collegiate Athletic Association (NCAA) collegiate baseball players, who were familiar with the current strength and conditioning program and had a minimum of 1 year of formal collegiate strength and conditioning experience, participated in this off-season training study. None of the men had participated in CAT before. Subjects were matched following a maximal effort (1-repetition maximum [1-RM]) bench press test in week 1, then were randomly assigned into a band-based CAT group or a chain-based CAT group and participated in a 5-week training phase that included bench pressing twice per week. Upper body strength was measured by 1-RM bench press again at week 6. A 2 × 2 mixed factorial (method × time) analysis of variance was calculated to compare differences across groups. The alpha level was set at P<0.05. Results No difference (F1,22=0.04, P=0.84) existed between the band-based CAT and chain-based CAT groups. A significant difference was observed between pre- and posttests of 1-RM bench (F1,22=88.46, P=0.001). Conclusion A 5-week band CAT or chain CAT training program used in conjunction with an off-season strength and conditioning program can increase maximal upper body strength in collegiate baseball athletes. Using band CAT and/or chain CAT as a training modality in the off-season will vary the training stimulus from the traditional and likely help to maintain the athlete’s interest. PMID:25177154

Strength training for plantar fasciitis and the intrinsic foot musculature: A systematic review.

PubMed

Huffer, Dean; Hing, Wayne; Newton, Richard; Clair, Mike

2017-03-01

The aim was to critically evaluate the literature investigating strength training interventions in the treatment of plantar fasciitis and improving intrinsic foot musculature strength. A search of PubMed, CINHAL, Web of Science, SPORTSDiscus, EBSCO Academic Search Complete and PEDRO using the search terms plantar fasciitis, strength, strengthening, resistance training, intrinsic flexor foot, resistance training. Seven articles met the eligibility criteria. Methodological quality was assessed using the modified Downs and Black checklist. All articles showed moderate to high quality, however external validity was low. A comparison of the interventions highlights significant differences in strength training approaches to treating plantar fasciitis and improving intrinsic strength. It was not possible to identify the extent to which strengthening interventions for intrinsic musculature may benefit symptomatic or at risk populations to plantar fasciitis. There is limited external validity that foot exercises, toe flexion against resistance and minimalist running shoes may contribute to improved intrinsic foot musculature function. Despite no plantar fascia thickness changes being observed through high-load plantar fascia resistance training there are indications that it may aid in a reduction of pain and improvements in function. Further research should use standardised outcome measures to assess intrinsic foot musculature strength and plantar fasciitis symptoms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experimental knee joint pain during strength training and muscle strength gain in healthy subjects: a randomized controlled trial.

PubMed

Sørensen, T J; Langberg, H; Hodges, P W; Bliddal, H; Henriksen, M

2012-01-01

Knee joint pain and reduced quadriceps strength are cardinal symptoms in many knee pathologies. In people with painful knee pathologies, quadriceps exercise reduces pain, improves physical function, and increases muscle strength. A general assumption is that pain compromises muscle function and thus may prevent effective rehabilitation. This study evaluated the effects of experimental knee joint pain during quadriceps strength training on muscle strength gain in healthy individuals. Twenty-seven healthy untrained volunteers participated in a randomized controlled trial of quadriceps strengthening (3 times per week for 8 weeks). Participants were randomized to perform resistance training either during pain induced by injections of painful hypertonic saline (pain group, n = 13) or during a nonpainful control condition with injection of isotonic saline (control group, n = 14) into the infrapatellar fat pad. The primary outcome measure was change in maximal isokinetic muscle strength in knee extension/flexion (60, 120, and 180 degrees/second). The group who exercised with pain had a significantly larger improvement in isokinetic muscle strength at all angular velocities of knee extension compared to the control group. In knee flexion there were improvements in isokinetic muscle strength in both groups with no between-group differences. Experimental knee joint pain improved the training-induced gain in muscle strength following 8 weeks of quadriceps training. It remains to be studied whether knee joint pain has a positive effect on strength gain in patients with knee pathology. Copyright © 2012 by the American College of Rheumatology.

An examination of current practices and gender differences in strength and conditioning in a sample of varsity high school athletic programs.

PubMed

Reynolds, Monica L; Ransdell, Lynda B; Lucas, Shelley M; Petlichkoff, Linda M; Gao, Yong

2012-01-01

Currently, little is known about strength and conditioning programs at the high school level. Therefore, the purpose of this research was to explore current practices in strength and conditioning for varsity high school athletes in selected sports. The following were specifically examined: who administers programs for these athletes, what kinds of training activities are done, and whether the responsible party or emphasis changes depending on the gender of the athletes. Coaches of varsity soccer, basketball, softball, and baseball in 3 large Idaho school districts were asked to complete an online survey. Sixty-seven percent (32/48) of the questionnaires were completed and used for the study. The majority of coaches (84%) provided strength and conditioning opportunities for their athletes, although only 37% required participation. Strength training programs were designed and implemented primarily by either physical education teachers or head coaches. Compared with coaches of male athletes, coaches of female athletes were less likely to know the credentials of their strength coaches, and they were less likely to use certified coaches to plan and implement their strength and conditioning programs. Most programs included dynamic warm-ups and cool-downs, plyometrics, agility training, speed training, and conditioning, and most programs were conducted 3 d·wk(-1) (76%) for sessions lasting between 30 and 59 minutes (63%). Compared with their female counterparts, male athletes were more likely to have required training, participate in strength training year round, and train using more sessions per week. This study provides additional information related to the practice of strength and conditioning in a sample of high school athletic teams.

Strength training improves the tri-digit finger-pinch force control of older adults.

PubMed

Keogh, Justin W; Morrison, Steve; Barrett, Rod

2007-08-01

To investigate the effect of unilateral upper-limb strength training on the finger-pinch force control of older men. Pretest and post-test 6-week intervention study. Exercise science research laboratory. Eleven neurologically fit older men (age range, 70-80y). The strength training group (n=7) trained twice a week for 6 weeks, performing dumbbell bicep curls, wrist flexions, and wrists extensions, while the control group subjects (n=4) maintained their normal activities. Changes in force variability, targeting error, peak power frequency, proportional power, sample entropy, digit force sharing, and coupling relations were assessed during a series of finger-pinch tasks. These tasks involved maintaining a constant or sinusoidal force output at 20% and 40% of each subject's maximum voluntary contraction. All participants performed the finger-pinch tasks with both the preferred and nonpreferred limbs. Analysis of covariance for between-group change scores indicated that the strength training group (trained limb) experienced significantly greater reductions in finger-pinch force variability and targeting error, as well as significantly greater increases in finger-pinch force, sample entropy, bicep curl, and wrist flexion strength than did the control group. A nonspecific upper-limb strength-training program may improve the finger-pinch force control of older men.

Modeling Heavy/Medium-Duty Fuel Consumption Based on Drive Cycle Properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Lijuan; Duran, Adam; Gonder, Jeffrey

This paper presents multiple methods for predicting heavy/medium-duty vehicle fuel consumption based on driving cycle information. A polynomial model, a black box artificial neural net model, a polynomial neural network model, and a multivariate adaptive regression splines (MARS) model were developed and verified using data collected from chassis testing performed on a parcel delivery diesel truck operating over the Heavy Heavy-Duty Diesel Truck (HHDDT), City Suburban Heavy Vehicle Cycle (CSHVC), New York Composite Cycle (NYCC), and hydraulic hybrid vehicle (HHV) drive cycles. Each model was trained using one of four drive cycles as a training cycle and the other threemore » as testing cycles. By comparing the training and testing results, a representative training cycle was chosen and used to further tune each method. HHDDT as the training cycle gave the best predictive results, because HHDDT contains a variety of drive characteristics, such as high speed, acceleration, idling, and deceleration. Among the four model approaches, MARS gave the best predictive performance, with an average absolute percent error of -1.84% over the four chassis dynamometer drive cycles. To further evaluate the accuracy of the predictive models, the approaches were first applied to real-world data. MARS outperformed the other three approaches, providing an average absolute percent error of -2.2% of four real-world road segments. The MARS model performance was then compared to HHDDT, CSHVC, NYCC, and HHV drive cycles with the performance from Future Automotive System Technology Simulator (FASTSim). The results indicated that the MARS method achieved a comparative predictive performance with FASTSim.« less

Effects of Exercise Modality During Additional "High-Intensity Interval Training" on Aerobic Fitness and Strength in Powerlifting and Strongman Athletes.

PubMed

Androulakis-Korakakis, Patroklos; Langdown, Louis; Lewis, Adam; Fisher, James P; Gentil, Paulo; Paoli, Antonio; Steele, James

2018-02-01

Androulakis-Korakakis, P, Langdown, L, Lewis, A, Fisher, JP, Gentil, P, Paoli, A, and Steele, J. Effects of exercise modality during additional "high-intensity interval training" on aerobic fitness and strength in powerlifting and strongman athletes. J Strength Cond Res 32(2): 450-457, 2018-Powerlifters and strongman athletes have a necessity for optimal levels of muscular strength while maintaining sufficient aerobic capacity to perform and recover between events. High-intensity interval training (HIIT) has been popularized for its efficacy in improving both aerobic fitness and strength but never assessed within the aforementioned population group. This study looked to compare the effect of exercise modality, e.g., a traditional aerobic mode (AM) and strength mode (SM), during HIIT on aerobic fitness and strength. Sixteen well resistance-trained male participants, currently competing in powerlifting and strongman events, completed 8 weeks of approximately effort- and volume-matched HIIT in 2 groups: AM (cycling, n = 8) and SM (resistance training, n = 8). Aerobic fitness was measured as predicted V[Combining Dot Above]O2max using the YMCA 3 minutes step test and strength as predicted 1 repetition maximum from a 4-6RM test using a leg extension. Both groups showed significant improvements in both strength and aerobic fitness. There was a significant between-group difference for aerobic fitness improvements favoring the AM group (p ≤ 0.05). There was no between-group difference for change in strength. Magnitude of change using within-group effect size for aerobic fitness and strength was considered large for each group (aerobic fitness, AM = 2.6, SM = 2.0; strength, AM = 1.9, SM = 1.9). In conclusion, our results support enhanced strength and aerobic fitness irrespective of exercise modality (e.g., traditional aerobic and resistance training). However, powerlifters and strongman athletes wishing to enhance their aerobic fitness should consider HIIT using an aerobic HIIT mode.

Short-Term Effects of Whole-Body Vibration Combined with Task-Related Training on Upper Extremity Function, Spasticity, and Grip Strength in Subjects with Poststroke Hemiplegia: A Pilot Randomized Controlled Trial.

PubMed

Lee, Jung-Sun; Kim, Chang-Yong; Kim, Hyeong-Dong

2016-08-01

The aim of this study was to determine the effect of whole-body vibration training combined with task-related training on arm function, spasticity, and grip strength in subjects with poststroke hemiplegia. Forty-five subjects with poststroke were randomly allocated to 3 groups, each with 15 subjects as follows: control group, whole-body vibration group, and whole-body vibration plus task-related training group. Outcome was evaluated by clinical evaluation and measurements of the grip strength before and 4 weeks after intervention. Our results show that there was a significantly greater increase in the Fugl-Meyer scale, maximal grip strength of the affected hand, and grip strength normalized to the less affected hand in subjects undergoing the whole-body vibration training compared with the control group after the test. Furthermore, there was a significantly greater increase in the Wolf motor function test and a decrease in the modified Ashworth spasticity total scores in subjects who underwent whole-body vibration plus task-related training compared with those in the other 2 groups after the test. The findings indicate that the use of whole-body vibration training combined with task-related training has more benefits on the improvement of arm function, spasticity, and maximal grip strength than conventional upper limb training alone or with whole-body vibration in people with poststroke hemiplegia.

Prepubescent Strength Training Gains Support.

ERIC Educational Resources Information Center

Duda, Marty

1986-01-01

Recent studies have stimulated greater support for prepubescent weight training. There seems to be general agreement that strength and weight training, when practiced under properly controlled conditions, is safe and efficacious for prepubescents. Weight lifting is not supported. Recommendations for weight training are made, and reservations are…

Evaluation of Heavy Metal Removal from Wastewater in a Modified Packed Bed Biofilm Reactor

PubMed Central

Azizi, Shohreh; Kamika, Ilunga; Tekere, Memory

2016-01-01

For the effective application of a modified packed bed biofilm reactor (PBBR) in wastewater industrial practice, it is essential to distinguish the tolerance of the system for heavy metals removal. The industrial contamination of wastewater from various sources (e.g. Zn, Cu, Cd and Ni) was studied to assess the impacts on a PBBR. This biological system was examined by evaluating the tolerance of different strengths of composite heavy metals at the optimum hydraulic retention time (HRT) of 2 hours. The heavy metal content of the wastewater outlet stream was then compared to the source material. Different biomass concentrations in the reactor were assessed. The results show that the system can efficiently treat 20 (mg/l) concentrations of combined heavy metals at an optimum HRT condition (2 hours), while above this strength there should be a substantially negative impact on treatment efficiency. Average organic reduction, in terms of the chemical oxygen demand (COD) of the system, is reduced above the tolerance limits for heavy metals as mentioned above. The PBBR biological system, in the presence of high surface area carrier media and a high microbial population to the tune of 10 000 (mg/l), is capable of removing the industrial contamination in wastewater. PMID:27186636

Shoulder muscle strength in paraplegics before and after kayak ergometer training.

PubMed

Bjerkefors, Anna; Jansson, Anna; Thorstensson, Alf

2006-07-01

The purpose was to investigate if shoulder muscle strength in post-rehabilitated persons with spinal cord injury (SCI) was affected by kayak ergometer training and to compare shoulder strength in persons with SCI and able-bodied persons. Ten persons with SCI (7 males and 3 females, injury levels T3-T12) performed 60 min kayak ergometer training three times a week for 10 weeks with progressively increased intensity. Maximal voluntary concentric contractions were performed during six shoulder movements: flexion and extension (range of motion 65 degrees ), abduction and adduction (65 degrees ), and external and internal rotation (60 degrees ), with an angular velocity of 30 degrees s(-1). Position specific strength was assessed at three shoulder angles (at the beginning, middle and end of the range of motion) in the respective movements. Test-retests were performed for all measurements before the training and the mean intraclass correlation coefficient was 0.941 (95% CI 0.928-0.954). There was a main effect of kayak ergometer training with increased shoulder muscle strength after training in persons with SCI. The improvements were independent of shoulder movement, and occurred in the beginning and middle positions. A tendency towards lower shoulder muscle strength was observed in the SCI group compared to a matched reference group of able-bodied persons. Thus, it appears that post-rehabilitated persons with SCI have not managed to fully regain/maintain their shoulder muscle strength on a similar level as that of able-bodied persons, and are able to improve their shoulder muscle strength after a period of kayak ergometer training.

Using goal orientations to understand motivation in strength training.

PubMed

Gilson, Todd A; Chow, Graig M; Ewing, Martha E

2008-07-01

Despite the importance that today's athletics place on strength training, research exploring the motivation of athletes in this arena is sparse. It is known that not all athletes will use the same motivational cognitions as inspiration, and these differences can be explored through achievement goal orientations. Through questionnaire data and semistructured interviews, the present study investigated how collegiate athletes maintain high levels of motivation over a period of time during strength training and explored relationships among five goal orientations: task-orientation, self-enhancing ego-orientation, self-defeating ego-orientation, social-approval orientation, and work-avoidance orientation. Subjects (N = 133), comprising 90 men and 43 women, were current varsity collegiate athletes from 15 different sports at a major Midwestern university. In addition, using a screener survey to assess achievement goal orientations, 15 subjects from the sample group who demonstrated a stronger inclination to only one achievement goal orientation were interviewed to gain a more in-depth understanding of their motivation cognitions in strength training. Results showed that the strongest achievement goal orientations reported from all athletes were task-orientation and social-approval. Additionally, five higher-order themes (significant others, improvement, competitive demands, being stronger than others, and miscellaneous) were consistent among the interviewed athletes when describing how they stay motivated during strength training. Whereas all athletes were able to describe at least one motivational strategy they employed during strength training, the dominant achievement goal orientation of some athletes influenced their motivational strategy. By employing the T.A.R.G.E.T. model (), strength coaches can foster adaptive achievement goal orientations and thereby enhance intrinsic motivation for athletes engaging in strength training.

The Effect of Special Operations Training on Testosterone, Lean Body Mass, and Strength and the Potential for Therapeutic Testosterone Replacement: A Review of the Literature

DTIC Science & Technology

2016-07-01

Effects of Testosterone or Anabolic Androgenic Steroid on Body Mass, Lean Body Mass, and Strength in Patients with Disease or Muscle Wasting...of Ranger training reportedly decreased body mass, fat mass, and lean body mass (LBM), with reductions in field measures of strength and power of...Table 3. Effects of Testosterone or Anabolic Androgenic Steroid with Resistance Training on Lean Body Mass and Strength Source Subjects Treatment

Effects of Nintendo Wii Fit Plus training on ankle strength with functional ankle instability

PubMed Central

Kim, Ki-Jong; Jun, Hyun-Ju; Heo, Myoung

2015-01-01

[Purpose] The objective of this study was to examine the effects of a training program using the Nintendo Wii Fit Plus on the ankle muscle strengths of subjects with functional ankle instability. [Subjects and Methods] This study was conducted using subjects in their 20s who had functional ankle instability. They were randomized to a strengthening training group and a balance training group with 10 subjects in each, and they performed an exercise using Nintendo Wii Fit Plus for 20 minutes. In addition, every participant completed preparation and finishing exercises for 5 minutes, respectively. [Results] The muscle strengths after conducting plantar flexion and dorsiflexion significantly increased at the angular velocities of 60° and 120° in the strengthening training group. Furthermore, the muscle strengths after conducting plantar flexion, dorsiflexion, eversion, and inversion significantly increased at the angular velocities of 60° and 120° in the balance training group. [Conclusion] The balance training group using Nintendo Wii Fit Plus showed better results than the strengthening training group. Consequently, it is recommended to add the balance training program of the Nintendo Wii Fit Plus to conventional exercise programs to improve ankle muscle strength in functional ankle instability at a low cost. PMID:26696703

Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review

PubMed Central

Rio, Ebonie; Kidgell, Dawson; Moseley, G Lorimer; Docking, Sean; Purdam, Craig; Cook, Jill

2016-01-01

Tendinopathy can be resistant to treatment and often recurs, implying that current treatment approaches are suboptimal. Rehabilitation programmes that have been successful in terms of pain reduction and return to sport outcomes usually include strength training. Muscle activation can induce analgesia, improving self-efficacy associated with reducing one's own pain. Furthermore, strength training is beneficial for tendon matrix structure, muscle properties and limb biomechanics. However, current tendon rehabilitation may not adequately address the corticospinal control of the muscle, which may result in altered control of muscle recruitment and the consequent tendon load, and this may contribute to recalcitrance or symptom recurrence. Outcomes of interest include the effect of strength training on tendon pain, corticospinal excitability and short interval cortical inhibition. The aims of this concept paper are to: (1) review what is known about changes to the primary motor cortex and motor control in tendinopathy, (2) identify the parameters shown to induce neuroplasticity in strength training and (3) align these principles with tendon rehabilitation loading protocols to introduce a combination approach termed as tendon neuroplastic training. Strength training is a powerful modulator of the central nervous system. In particular, corticospinal inputs are essential for motor unit recruitment and activation; however, specific strength training parameters are important for neuroplasticity. Strength training that is externally paced and akin to a skilled movement task has been shown to not only reduce tendon pain, but modulate excitatory and inhibitory control of the muscle and therefore, potentially tendon load. An improved understanding of the methods that maximise the opportunity for neuroplasticity may be an important progression in how we prescribe exercise-based rehabilitation in tendinopathy for pain modulation and potentially restoration of the corticospinal control of the muscle-tendon complex. PMID:26407586

Systematic strength training as a model of therapeutic intervention. A controlled trial in postmenopausal women with osteopenia.

PubMed

Hartard, M; Haber, P; Ilieva, D; Preisinger, E; Seidl, G; Huber, J

1996-01-01

Physical exercise is often recommended as a therapeutic tool to combat pre- and postmenopausal loss of bone density. However, the relationship between training dosage (intensity, duration, frequency) and the effect on bone density still is undergoing discussion. Furthermore, the exercise quantification programs are often described so inadequately that they are neither quantitatively nor qualitatively reproducible. The aim of this investigation was to determine whether a clearly defined training of muscle strength, under defined safety aspects, performed only twice weekly, can counteract bone density loss in women with postmenopausal osteopenia. Data from 16 women in the training group (age, 63.6 +/- 6.2 yr) and 15 women in the control group (age, 67.4 +/-9.7 yr), of comparable height and weight, were evaluated. Strength training was performed for 6 mo as continually adapted strength training, providing an intensity of about 70% of each test person's one repetition maximum. Bone mineral density of lumbar vertebrae 2 to 4 and the femoral neck was measured by dual-energy x-ray absorptiometry. Maximum performance in watts and parameters of hemodynamics were controlled with a bicycle ergometer test to maximal effort. In addition, metabolic data were assessed. In the lumbar spine and femoral neck, the training group showed no significant changes, whereas the control group demonstrated a significant loss of bone mineral density, especially in the femoral neck (P<0.05). The strength increase was highly significant in all exercised muscle groups, rising to about 70% above the pretraining status (P<0.001). Heart rate and blood pressure data indicated a slight economization, metabolism was not significantly influenced. Based on these findings, we conclude that continually adapted strength training is an effective, safe, reproducible, and adaptable method of therapeutic strength training, following only two exercise sessions per week.

Neuromuscular Electrical Stimulation Versus Volitional Isometric Strength Training in Children With Spastic Diplegic Cerebral Palsy: A Preliminary Study

PubMed Central

Stackhouse, Scott K.; Binder-Macleod, Stuart A.; Stackhouse, Carrie A.; McCarthy, James J.; Prosser, Laura A.; Lee, Samuel C. K.

2011-01-01

Background To date, no reports have investigated neuromuscular electrical stimulation (NMES) to increase muscle force production of children with cerebral palsy (CP) using high-force contractions and low repetitions. Objective The aims of this study were to determine if isometric NMES or volitional training in children with CP could increase muscle strength and walking speed and to examine the mechanisms that may contribute to increased force production. Methods Eleven children with spastic diplegia were assigned to an NMES training group or to a volitional training group. Participants in the NMES group had electrodes implanted percutaneously to activate the quadriceps femoris and triceps surae muscles. The volitional group trained with maximal effort contractions. Both groups performed a 12-week isometric strength-training program. Maximum voluntary isometric contract ion (MVIC) force, voluntary muscle activation, quadriceps and triceps surae cross-sectional area (CSA), and walking speed were measured pre- and post-strength training. Results The NMES-trained group had greater increases in normalized force production for both die quadriceps femoris and triceps surae. Similarly only the NMES group showed an increase in walking speed after training. Changes in voluntary muscle activation explained approximately 67% and 37% of the changes seen in the MVIC of the NMES and volitional groups, respectively. Quadriceps femoris maximum CSA increased significantly for the NMES group only. Conclusions This study was the first to quantitatively show strength gains with the use of NMES in children with CP. These results support the need for future experimental studies that will examine the clinical effectiveness of NMES strength training. PMID:17369515

Increased muscle strength improves managing in activities of daily living in fall-prone community-dwelling older women.

PubMed

Vaapio, Sari; Salminen, Marika; Vahlberg, Tero; Kivelä, Sirkka-Liisa

2011-02-01

The aim of this longitudinal study was to describe whether an increase in knee extension strength is associated with improvements in managing in activities of daily living (ADL) and in self-perceived physical condition in fall-prone community-dwelling older women. Subjects (n=417) aged ≥ 65 years belonged either to intervention or control groups in a 12-month randomized controlled fall prevention trial. Isometric muscle strength of knee extension was measured with an adjustable dynamometer chair. Managing in activities of daily living was measured with structured questions about abilities to climb stairs, walk at least 400 meters, toilet, bath, go to the sauna, do light or heavy housework, and carry heavy loads. A question of self-perceived physical condition was also asked. Positive associations were found between increased knee extension strength and an increase in walking at least 400 meters (p<0.001), carrying heavy loads (p=0.004), and climbing stairs (p=0.007), and in self perceived physical condition (p=0.005) over a 12- month follow-up. In addition, low age, non-use of a walking aid, low number of prescribed medications, and good functional balance at baseline were associated with an increase in performance of these ADL functions. An increase in knee extension strength during the 12-month follow-up was associated with improvement in some ADL functions and improvement in self-perceived physical condition during the same period in fall-prone community-dwelling women.

Intensive exercise training suppresses testosterone during bed rest

NASA Technical Reports Server (NTRS)

Wade, C. E.; Stanford, K. I.; Stein, T. P.; Greenleaf, J. E.

2005-01-01

Spaceflight and prolonged bed rest (BR) alter plasma hormone levels inconsistently. This may be due, in part, to prescription of heavy exercise as a countermeasure for ameliorating the adverse effects of disuse. The initial project was to assess exercise programs to maintain aerobic performance and leg strength during BR. The present study evaluates the effect of BR and the performance of the prescribed exercise countermeasures on plasma steroid levels. In a 30-day BR study of male subjects, the efficacy of isotonic (ITE, n = 7) or isokinetic exercise (IKE, n = 7) training was evaluated in contrast to no exercise (n = 5). These exercise countermeasures protected aerobic performance and leg strength successfully. BR alone (no-exercise group) did not change steroidogenesis, as assessed by the plasma concentrations of cortisol, progesterone, aldosterone, and free (FT) and total testosterone (TT). In the exercise groups, both FT and TT were decreased (P < 0.05): FT during IKE from 24 +/- 1.7 to 18 +/- 2.0 pg/ml and during ITE from 21 +/- 1.5 to 18 +/- 1 pg/ml, and TT during IKE from 748 +/- 68 to 534 +/- 46 ng/dl and during ITE from 565 +/- 36 to 496 +/- 38 ng/dl. The effect of intensive exercise countermeasures on plasma testosterone was not associated with indexes of overtraining. The reduction in plasma testosterone associated with both the IKE and ITE countermeasures during BR supports our hypothesis that intensive exercise countermeasures may, in part, contribute to changes in plasma steroid concentrations during spaceflight.

Upper-body strength gains from different modes of resistance training in women who are underweight and women who are obese.

PubMed

Mayhew, Jerry L; Smith, Abbie E; Arabas, Jana L; Roberts, B Scott

2010-10-01

The purpose of this study was to determine the degree of upper-body strength gained by college women who are underweight and those who are obese using different modes of resistance training. Women who were underweight (UWW, n = 93, weight = 49.3 ± 4.5 kg) and women who were obese (OBW, n = 73, weight = 94.0 ± 15.1 kg) were selected from a larger cohort based on body mass index (UWW ≤ 18.5 kg·m⁻²; OBW ≥ 30 kg·m⁻²). Subjects elected to train with either free weights (FW, n = 38), supine vertical bench press machine (n = 52) or seated horizontal bench press machine (n = 76) using similar linear periodization resistance training programs 3× per week for 12 weeks. Each participant was assessed for upper-body strength using FWs (general) and machine weight (specific) 1 repetition maximum bench press before and after training. Increases in general and mode-specific strength were significantly greater for OBW (5.2 ± 5.1 and 9.6 ± 5.1 kg, respectively) than for UWW (3.5 ± 4.1 and 7.2 ± 5.2 kg, respectively). General strength gains were not significantly different among the training modes. Mode-specific gains were significantly greater (p < 0.05) than general strength gains for all groups. In conclusion, various resistance training modes may produce comparable increases in general strength but will register greater gains if measured using the specific mode employed for training, regardless of the weight category of the individual.

Effect of an herbal/botanical supplement on strength, balance, and muscle function following 12-weeks of resistance training: a placebo controlled study.

PubMed

Furlong, Jonathan; Rynders, Corey A; Sutherlin, Mark; Patrie, James; Katch, Frank I; Hertel, Jay; Weltman, Arthur

2014-01-01

StemSport (SS; StemTech International, Inc. San Clemente, CA) contains a proprietary blend of the botanical Aphanizomenon flos-aquae and several herbal antioxidant and anti-inflammatory substances. SS has been purported to accelerate tissue repair and restore muscle function following resistance exercise. Here, we examine the effects of SS supplementation on strength adaptations resulting from a 12-week resistance training program in healthy young adults. Twenty-four young adults (16 males, 8 females, mean age = 20.5 ± 1.9 years, mass = 70.9 ± 11.9 kg, stature = 176.6 ± 9.9 cm) completed the twelve week training program. The study design was a double-blind, placebo controlled parallel group trial. Subjects either received placebo or StemSport supplement (SS; mg/day) during the training. 1-RM bench press, 1-RM leg press, vertical jump height, balance (star excursion and center of mass excursion), isokinetic strength (elbow and knee flexion/extension) and perception of recovery were measured at baseline and following the 12-week training intervention. Resistance training increased 1-RM strength (p < 0.008), vertical jump height (p < 0.03), and isokinetic strength (p < 0.05) in both SS and placebo groups. No significant group-by-time interactions were observed (all p-values >0.10). These data suggest that compared to placebo, the SS herbal/botanical supplement did not enhance training induced adaptations to strength, balance, and muscle function above strength training alone.

[Significance of physical training on prevention in elderly patients].

PubMed

Baum, K

2002-07-01

The loss of strength, coordination, endurance, and flexibility with increasing age is only partly due to the aging process itself. A major factor is physical activity, i.e. the influence of implicit or explicit training stimuli. All elements of physical performance can be improved through training even in the very old, if the intensity and frequency of training are adequate. For the elderly, strength and coordination are particularly important elements of training since they constitute a prerequisite for an independent way of living. To minimize the cardiovascular risks during strength training, we developed and tested a new method which leads to significantly smaller increases in blood pressure than conventional approaches.

Feasibility and effects of a combined adjuvant high-intensity interval/strength training in breast cancer patients: a single-center pilot study.

PubMed

Schulz, Sebastian Viktor Waldemar; Laszlo, Roman; Otto, Stephanie; Prokopchuk, Dmytro; Schumann, Uwe; Ebner, Florian; Huober, Jens; Steinacker, Jürgen Michael

2018-06-01

To evaluate feasibility of an exercise intervention consisting of high-intensity interval endurance and strength training in breast cancer patients. Twenty-six women with nonmetastatic breast cancer were consecutively assigned to the exercise intervention- (n= 15, mean age 51.9 ± 9.8 years) and the control group (n = 11, mean age 56.9 ± 7.0 years). Cardiopulmonary exercise testing that included lactate sampling, one-repetition maximum tests and a HADS-D questionnaire were used to monitor patients both before and after a supervised six weeks period of either combined high-intensity interval endurance and strength training (intervention group, twice a week) or leisure training (control group). Contrarily to the control group, endurance (mean change of VO 2 , peak 12.0 ± 13.0%) and strength performance (mean change of cumulative load 25.9 ± 11.2%) and quality of life increased in the intervention group. No training-related adverse events were observed. Our guided exercise intervention could be used effectively for initiation and improvement of performance capacity and quality of life in breast cancer patients in a relatively short time. This might be especially attractive during medical treatment. Long-term effects have to be evaluated in randomized controlled studies also with a longer follow-up. Implications for Rehabilitation High-intensity interval training allows improvement of aerobic capacity within a comparable short time. Standard leisure training in breast cancer patients is rather suitable for the maintenance of performance capacity and quality of life. Guided high-intensity interval training combined with strength training can be used effectively for the improvement of endurance and strength capacity and also quality of life. After exclusion of contraindications, guided adjuvant high-intensity interval training combined with strength training can be safely used in breast cancer patients.

The compatibility of concurrent high intensity interval training and resistance training for muscular strength and hypertrophy: a systematic review and meta-analysis.

PubMed

Sabag, Angelo; Najafi, Abdolrahman; Michael, Scott; Esgin, Tuguy; Halaki, Mark; Hackett, Daniel

2018-04-16

The purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = -0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = -0.377, p = 0.074) and not running (ES = -0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.

A Systematic Review of Isometric Lingual Strength-Training Programs in Adults With and Without Dysphagia.

PubMed

McKenna, Victoria S; Zhang, Bin; Haines, Morgan B; Kelchner, Lisa N

2017-05-17

This systematic review summarizes the effects of isometric lingual strength training on lingual strength and swallow function in adult populations. Furthermore, it evaluates the designs of the reviewed studies and identifies areas of future research in isometric lingual strength training for dysphagia remediation. A comprehensive literature search of 3 databases and additional backward citation search identified 10 studies for inclusion in the review. The review reports and discusses the isometric-exercise intervention protocols, pre- and postintervention lingual-pressure data (maximum peak pressures and lingual-palatal pressures during swallowing), and oropharyngeal swallowing measures such as penetration-aspiration scales, oropharyngeal residue and duration, lingual volumes, and quality-of-life assessments. Studies reported gains in maximum peak lingual pressures following isometric lingual strength training for both healthy adults and select groups of individuals with dysphagia. However, due to the variability in study designs, it remains unclear whether strength gains generalize to swallow function. Although isometric lingual strength training is a promising intervention for oropharyngeal dysphagia, the current literature is too variable to confidently report specific therapeutic benefits. Future investigations should target homogenous patient populations and use randomized controlled trials to determine the efficacy of this treatment for individuals with dysphagia.

Effects of Swiss-ball core strength training on strength, endurance, flexibility, and balance in sedentary women.

PubMed

Sekendiz, Betül; Cuğ, Mutlu; Korkusuz, Feza

2010-11-01

The purpose of this study was to investigate the effects of Swiss-ball core strength training on trunk extensor (abdominal)/flexor (lower back) and lower limb extensor (quadriceps)/flexor (hamstring) muscular strength, abdominal, lower back and leg endurance, flexibility and dynamic balance in sedentary women (n = 21; age = 34 ± 8.09; height = 1.63 ± 6.91 cm; weight = 64 ± 8.69 kg) trained for 45 minutes, 3 d·wk-1 for 12 weeks. Results of multivariate analysis revealed significant difference (p ≤ 0.05) between pre and postmeasures of 60 and 90° s trunk flexion/extension, 60 and 240° s-1 lower limb flexion/extension (Biodex Isokinetic Dynamometer), abdominal endurance (curl-up test), lower back muscular endurance (modified Sorensen test), lower limb endurance (repetitive squat test), lower back flexibility (sit and reach test), and dynamic balance (functional reach test). The results support the fact that Swiss-ball core strength training exercises can be used to provide improvement in the aforementioned measures in sedentary women. In conclusion, this study provides practical implications for sedentary individuals, physiotherapists, strength and conditioning specialists who can benefit from core strength training with Swiss balls.

The Effects of a Sport-Specific Maximal Strength and Conditioning Training on Critical Velocity, Anaerobic Running Distance, and 5-km Race Performance.

PubMed

Karsten, Bettina; Stevens, Liesbeth; Colpus, Mark; Larumbe-Zabala, Eneko; Naclerio, Fernando

2016-01-01

To investigate the effects of a sport-specific maximal 6-wk strength and conditioning program on critical velocity (CV), anaerobic running distance (ARD), and 5-km time-trial performance (TT). 16 moderately trained recreational endurance runners were tested for CV, ARD, and TT performances on 3 separate occasions (baseline, midstudy, and poststudy). Participants were randomly allocated into a strength and conditioning group (S&C; n = 8) and a comparison endurance-training-only group (EO; n = 8). During the first phase of the study (6 wk), the S&C group performed concurrent maximal strength and endurance training, while the EO group performed endurance-only training. After the retest of all variables (midstudy), both groups subsequently, during phase 2, performed another 6 wk of endurance-only training that was followed by poststudy tests. No significant change for CV was identified in either group. The S&C group demonstrated a significant decrease for ARD values after phases 1 and 2 of the study. TT performances were significantly different in the S&C group after the intervention, with a performance improvement of 3.62%. This performance increase returned close to baseline after the 6-wk endurance-only training. Combining a 6-wk resistance-training program with endurance training significantly improves 5-km TT performance. Removing strength training results in some loss of those performance improvements.

Early phase adaptations in muscle strength and hypertrophy as a result of low-intensity blood flow restriction resistance training.

PubMed

Hill, Ethan C; Housh, Terry J; Keller, Joshua L; Smith, Cory M; Schmidt, Richard J; Johnson, Glen O

2018-06-22

Low-intensity venous blood flow restriction (vBFR) resistance training has been shown to promote increases in muscle strength and size. Eccentric-only muscle actions are typically a more potent stimulus to increase muscle strength and size than concentric-only muscle actions performed at the same relative intensities. Therefore, the purpose of this investigation was to examine the time-course of changes in muscle strength, hypertrophy, and neuromuscular adaptations following 4 weeks of unilateral forearm flexion low-intensity eccentric vBFR (Ecc-vBFR) vs. low-intensity concentric vBFR (Con-vBFR) resistance training performed at the same relative intensity. Thirty-six women were randomly assigned to either Ecc-vBFR (n = 12), Con-vBFR (n = 12) or control (no intervention, n = 12) group. Ecc-vBFR trained at 30% of eccentric peak torque and Con-vBFR trained at 30% of concentric peak torque. All training and testing procedures were performed at an isokinetic velocity of 120° s - ¹. Muscle strength increased similarly from 0 to 2 and 4 weeks of training as a result of Ecc-vBFR (13.9 and 35.0%) and Con-vBFR (13.4 and 31.2%), but there were no changes in muscle strength for the control group. Muscle thickness increased similarly from 0 to 2 and 4 weeks of training as a result of Ecc-vBFR (11.4 and 12.8%) and Con-vBFR (9.1 and 9.9%), but there were no changes for the control group. In addition, there were no changes in any of the neuromuscular responses. The Ecc-vBFR and Con-vBFR low-intensity training induced comparable increases in muscle strength and size. The increases in muscle strength, however, were not associated with neuromuscular adaptations.

Effects of Neuromuscular Training on Children and Young Adults with Down Syndrome: Systematic Review and Meta-Analysis.

PubMed

Sugimoto, Dai; Bowen, Samantha L; Meehan, William P; Stracciolini, Andrea

2016-08-01

To synthesize existing research evidence and examine effects of neuromuscular training on general strength, maximal strength, and functional mobility tasks in children and young adults with Down syndrome. PubMed and EBSCO were used as a data source. To attain the aim of this study, literature search was performed under following inclusion criteria: (1) included participants with Down syndrome, (2) implemented a neuromuscular training intervention and measured outcome variables of general strength, maximal strength, and functional mobility tasks, (3) had a group of participants whose mean ages were under 30 years old, (4) employed a prospective controlled design, and (5) used mean and standard deviations to express the outcome variables. Effect size was calculated from each study based on pre- and post-testing value differences in general strength, maximal strength, and functional mobility tasks between control and intervention groups. The effect size was further classified in to one of the following categories: small, moderate, and large effects. Seven studies met inclusion criteria. Analysis indicated large to moderate effects on general strength, moderate to small effects on maximal strength, and small effect on functional mobility tasks by neuromuscular training. Although there were limited studies, the results showed that neuromuscular training could be used as an effective intervention in children and young adults with Down syndrome. Synthesis of seven reviewed studies indicated that neuromuscular training could be beneficial to optimize general and maximal muscular strength development in children and young adults with Down syndrome. Copyright © 2016 Elsevier Ltd. All rights reserved.

Magnetic Field Effects on In-Medium ϒ Dissociation

NASA Astrophysics Data System (ADS)

Hoelck, Johannes; Nendzig, Felix; Wolschin, Georg

2017-12-01

The electromagnetic fields during relativistic heavy ion collisions are calculated using a simple model which characterises the emerging quark-gluon medium by its conductivity only. An estimate of the average magnetic field strength experienced by the bb¯ mesons produced in the collision is made. In a sufficiently strong magnetic field, the individual spins of bb¯ mesons can align with the field leading to quantum mixing of the singlet and triplet spin configurations. The extent of this intermixture, however, is found to be negligible at field strengths occurring in heavy ion collisions at LHC energies.

Tetramers of Two Heavy and Two Light Bosons

NASA Astrophysics Data System (ADS)

Naidon, Pascal

2018-07-01

This article considers the bound states of two heavy and two light bosons, when a short-range force attracts the bosons of different mass, and a short-range force repels the light bosons. The existence of such four-body bound states results from the competition between these two forces. For a given strength of the attraction, the critical strength of the repulsion necessary to unbind the four particles is calculated. This study is motivated by the experimental realisation of impurity atoms immersed in an atomic Bose-Einstein condensate, and aims at determining in which regime only one boson contributes to binding two impurities.

Beyond a Deficit Model of Strengths Training in Schools: Teaching Targeted Strength Use to Gifted Students

ERIC Educational Resources Information Center

Bates-Krakoff, Justine; McGrath, Robert E.; Graves, Karen; Ochs, Lynn

2017-01-01

Prior literature on the use of character strengths suggests that both deficiencies and excesses in the use of strengths can be problematic. While most school-based training in character strengths tends to focus on the former issue, an example is provided of a school-based program offered by the Mayerson Academy in partnership with the VIA…

The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance.

PubMed

Ratamess, Nicholas A; Beller, Noah A; Gonzalez, Adam M; Spatz, Gregory E; Hoffman, Jay R; Ross, Ryan E; Faigenbaum, Avery D; Kang, Jie

2016-03-01

The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects' peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s(-1) [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey's post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key pointsMultiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women.Multiple-joint isokinetic resistance training increased 1RM strength in the bench press (by 10.2%), bent-over barbell row (by 11.2%), and maximal modified push-up performance (by 28.6%) indicating a carryover of training effects to dynamic exercise performance.The carryover effects may be attractive to strength training and conditioning professionals seeking to include alternative modalities such as multiple-joint isokinetic dynamometers to resistance training programs.

The Effects of Multiple-Joint Isokinetic Resistance Training on Maximal Isokinetic and Dynamic Muscle Strength and Local Muscular Endurance

PubMed Central

Ratamess, Nicholas A.; Beller, Noah A.; Gonzalez, Adam M.; Spatz, Gregory E.; Hoffman, Jay R.; Ross, Ryan E.; Faigenbaum, Avery D.; Kang, Jie

2016-01-01

The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects’ peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s-1 [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey’s post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key points Multiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women. Multiple-joint isokinetic resistance training increased 1RM strength in the bench press (by 10.2%), bent-over barbell row (by 11.2%), and maximal modified push-up performance (by 28.6%) indicating a carryover of training effects to dynamic exercise performance. The carryover effects may be attractive to strength training and conditioning professionals seeking to include alternative modalities such as multiple-joint isokinetic dynamometers to resistance training programs. PMID:26957924

Effects of Added Resistance Training on Physical Fitness, Body Composition, and Serum Hormone Concentrations During Eight Weeks of Special Military Training Period.

PubMed

Vaara, Jani P; Kokko, Juha; Isoranta, Manne; Kyröläinen, Heikki

2015-11-01

A high volume of military training has been shown to compromise muscle strength development. We examined effects of added low-volume resistance training during special military training (ST) period, which took place after basic training period. Male conscripts (n = 25) were assigned to standardized ST with added resistance training group (TG, n = 13) and group with standardized ST only (control) (CG, n = 12). Standardized ST with added resistance training group performed 2 resistance training sessions per week for 8 weeks: hypertrophic strength (weeks 1-3), maximal strength (weeks 4-6) and power training (weeks 7-8). Maximal strength tests, load carriage performance (3.2 km, 27 kg), and hormone concentrations were measured before and after ST (mean ± SD). Both groups improved similarly in their load carriage performance time (TG: 1,162 ± 116 seconds vs. 1,047 ± 81 seconds; CG: 1,142 ± 95 seconds vs. 1,035 ± 81 seconds) (p < 0.001) but decreased maximal strength of the lower extremities (TG: 5,250 ± 1,110 N vs. 4,290 ± 720 N; CG: 5,170 ± 1,050 N vs. 4,330 ± 1,230 N) and back muscles (TG: 4,290 ± 990 N vs. 3,570 ± 48 N; CG: 3,920 ± 72 N vs. 3,410 ± 53 N) (p ≤ 0.05). Maximal strength of the upper extremities improved in CG (1,040 ± 200 N vs. 1,140 ± 200 N) (p ≤ 0.05) but not in TG. Maximal strength of the abdominal muscles improved in TG (3,260 ± 510 N vs. 3,740 ± 75 N) (p ≤ 0.05) but not in CG. Testosterone concentration increased in CG (15.2 ± 3.6 nmol·L⁻¹ vs. 21.6 ± 5.0 nmol·L⁻¹) (p < 0.01) but not in TG (18.6 ± 4.3 nmol·L⁻¹ vs. 19.5 ± 9.4 nmol·L⁻¹). In conclusion, interference with strength gains might be related to the high volume of aerobic activities and too low volume of resistance training during ST. To develop strength characteristics, careful periodization and individualization should be adopted in ST.

The development, retention and decay rates of strength and power in elite rugby union, rugby league and American football: a systematic review.

PubMed

McMaster, Daniel Travis; Gill, Nicholas; Cronin, John; McGuigan, Michael

2013-05-01

Strength and power are crucial components to excelling in all contact sports; and understanding how a player's strength and power levels fluctuate in response to various resistance training loads is of great interest, as it will inevitably dictate the loading parameters throughout a competitive season. This is a systematic review of training, maintenance and detraining studies, focusing on the development, retention and decay rates of strength and power measures in elite rugby union, rugby league and American football players. A literature search using MEDLINE, EBSCO Host, Google Scholar, IngentaConnect, Ovid LWW, ProQuest Central, ScienceDirect Journals, SPORTDiscus and Wiley InterScience was conducted. References were also identified from other review articles and relevant textbooks. From 300 articles, 27 met the inclusion criteria and were retained for further analysis. STUDY QUALITY: Study quality was assessed via a modified 20-point scale created to evaluate research conducted in athletic-based training environments. The mean ± standard deviation (SD) quality rating of the included studies was 16.2 ± 1.9; the rating system revealed that the quality of future studies can be improved by randomly allocating subjects to training groups, providing greater description and detail of the interventions, and including control groups where possible. Percent change, effect size (ES = [Post-Xmean - Pre-Xmean)/Pre-SD) calculations and SDs were used to assess the magnitude and spread of strength and power changes in the included studies. The studies were grouped according to (1) mean intensity relative volume (IRV = sets × repetitions × intensity; (2) weekly training frequency per muscle group; and (3) detraining duration. IRV is the product of the number of sets, repetitions and intensity performed during a training set and session. The effects of weekly training frequencies were assessed by normalizing the percent change values to represent the weekly changes in strength and power. During the IRV analysis, the percent change values were normalized to represent the percent change per training session. The long-term periodized training effects (12, 24 and 48 months) on strength and power were also investigated. Across the 27 studies (n = 1,015), 234 percent change and 230 ES calculations were performed. IRVs of 11-30 (i.e., 3-6 sets of 4-10 repetitions at 74-88% one-repetition maximum [1RM]) elicited strength and power increases of 0.42% and 0.07% per training session, respectively. The following weekly strength changes were observed for two, three and four training sessions per muscle region/week: 0.9%, 1.8 % and 1.3 %, respectively. Similarly, the weekly power changes for two, three and four training sessions per muscle group/week were 0.1%, 0.3% and 0.7 %, respectively. Mean decreases of 14.5% (ES = -0.64) and 0.4 (ES = -0.10) were observed in strength and power across mean detraining periods of 7.2 ± 5.8 and 7.6 ± 5.1 weeks, respectively. The long-term training studies found strength increases of 7.1 ± 1.0% (ES = 0.55), 8.5 ± 3.3% (ES = 0.81) and 12.5 ± 6.8% (ES = 1.39) over 12, 24 and 48 months, respectively; they also found power increases of 14.6% (ES = 1.30) and 12.2% (ES = 1.06) at 24 and 48 months. Based on current findings, training frequencies of two to four resistance training sessions per muscle group/week can be prescribed to develop upper and lower body strength and power. IRVs ranging from 11 to 30 (i.e., 3-6 sets of 4-10 repetitions of 70-88% 1RM) can be prescribed in a periodized manner to retain power and develop strength in the upper and lower body. Strength levels can be maintained for up to 3 weeks of detraining, but decay rates will increase thereafter (i.e. 5-16 weeks). The effect of explosive-ballistic training and detraining on pure power development and decay in elite rugby and American football players remain inconclusive. The long-term effects of periodized resistance training programmes on strength and power seem to follow the law of diminishing returns, as training exposure increases beyond 12-24 months, adaptation rates are reduced.

Comparisons of low-intensity versus moderate-intensity combined aerobic and resistance training on body composition, muscle strength, and functional performance in older women.

PubMed

Shiotsu, Yoko; Yanagita, Masahiko

2018-06-01

This study aimed to examine the effects of exercise order of combined aerobic and low- or moderate-intensity resistance training into the same session on body composition, functional performance, and muscle strength in healthy older women. Furthermore, this study compared the effects of different (low- vs moderate-) intensity combined training. A total of 60 healthy older women (age 61-81 y) were randomly assigned to five groups that performed aerobic exercise before low-intensity resistance training (AR-L, n = 12) or after resistance training (RA-L, n = 12), performed aerobic exercise before moderate-intensity resistance training (AR-M, n = 12) or after resistance training (RA-M, n = 12), or nonintervention control conditions (CON, n = 12). Body composition, functional performance, and muscle strength were evaluated before and after the 10-week training. No effects of exercise order of combined aerobic and low- or moderate-intensity resistance training (AR-L vs RA-L, AR-M vs RA-M) were observed in body composition, functional performance, or muscle strength, whereas the effects of training intensity of combined training (AR-L vs AR-M, RA-L vs RA-M) were observed on functional performance. All combined trainings significantly increased muscle strength and gait ability (P < 0.01, respectively). Functional reach test significantly increased in the AR-M and RA-M groups (P < 0.01, respectively), and there were significant group differences between AR-L and AR-M (P = 0.002), RA-L and RA-M (P = 0.014). Preliminary findings suggest that combined aerobic and low- or moderate-intensity resistance training increases muscle strength and improves gait ability, regardless of the exercise order. Also, greater improvement in dynamic balance capacity, a risk factor associated with falling, is observed in moderate-intensity combined training.

Research and Development of Heavy Wall DNV485FDU Pipeline Plate for 3500M Deep Water Pipe Applications at Shougang

NASA Astrophysics Data System (ADS)

Ding, Wenhua; Li, Shaopo; Li, Jiading; Li, Qun; Chen, Tieqiang; Zhang, Hai

In recent years, there has been development of several significant pipeline projects for the transmission of oil and gas from deep water environments. The production of gas transmission pipelines for application demands heavy wall, high strength, good lower temperature toughness and good weldability. To overcome the difficulty of producing consistent mechanical property in heavy wall pipe Shougang Steel Research in cooperation with the Shougang Steel Qinhuangdao China (Shouqin) 4.3m heavy wide plate mill research was conducted.

Preserving mobility in older adults.

PubMed Central

Buchner, D M

1997-01-01

Age-related loss of strength contributes to impaired mobility and increases the risk of falls. Recent research has focused on 2 approaches to preventing age-related loss of strength--promoting physical activity and exercise (especially strength training) and using trophic factors to enhance muscle performance. Epidemiologic evidence strongly supports a role of regular physical activity in successful aging by preserving muscle performance, promoting mobility, and reducing fall risk. Randomized controlled trials provide convincing evidence that strength and endurance training improve muscle performance in older adults. Evidence is rapidly accumulating from randomized trials that endurance, strength, and balance training promote mobility and reduce fall risk, though exercise effects differ according to the type of exercise, details of the exercise program, and the target group of older adults. Because lifetime regular physical activity is recommended for all older adults, a reasonable strategy (especially for weak adults) is an activity program that includes strength training. In contrast, insufficient evidence exists to recommend the long-term use of trophic factors to preserve muscular performance. An intervention that merits additional study is avoiding the use of psychoactive drugs because drugs like benzodiazepines appear to be risk factors for inactivity and may have unrecognized direct effects on muscular performance. Because chronic illness is a risk factor for inactivity and disuse muscle atrophy, randomized trials comparing strength training with other interventions would be useful in understanding whether strength training has advantages in preserving muscle performance and improving health-related quality of life in a variety of chronic illnesses such as depressive illness. PMID:9348757

Optical spectroscopy and ultrafast pump-probe studies on the heavy-fermion compound CePt 2 In 7

DOE PAGES

Chen, R. Y.; Zhang, S. J.; Bauer, E. D.; ...

2016-07-29

We report optical spectroscopy and ultrafast pump-probe measurements on the antiferromagnetic heavy-fermion compound CePt 2 In 7 , a member showing stronger two dimensionality than other compounds in the CeIn 3 -derived heavy-fermion family. Here, we identify clear and typical hybridization spectral structures at low temperature from the two different spectroscopy probes. But, the strength and related energy scale of the hybridization are much weaker and smaller than that in the superconducting compounds CeCoIn 5 and CeIrIn 5 . The features are more similar to observations on the antiferromagnetic compounds CeIn 3 and CeRhIn 5 in the same family. Ourmore » results clearly indicate that the Kondo interaction and hybridizations exist in the antiferromagnetic compounds but with weaker strength.« less

Flight simulator platform motion and air transport pilot training

NASA Technical Reports Server (NTRS)

Lee, Alfred T.; Bussolari, Steven R.

1987-01-01

The effect of a flight simulator platform motion on the performance and training of a pilot was evaluated using subjective ratings and objective performance data obtained on experienced B-727 pilots and pilots with no prior heavy aircraft flying experience flying B-727-200 aircraft simulator used by the FAA in the upgrade and transition training for air carrier operations. The results on experienced pilots did not reveal any reliable effects of wide variations in platform motion design. On the other hand, motion variations significantly affected the behavior of pilots without heavy-aircraft experience. The effect was limited to pitch attitude control inputs during the early phase of landing training.

Comparison of Periodized and Non-Periodized Resistance Training on Maximal Strength: A Meta-Analysis.

PubMed

Williams, Tyler D; Tolusso, Danilo V; Fedewa, Michael V; Esco, Michael R

2017-10-01

Periodization is a logical method of organizing training into sequential phases and cyclical time periods in order to increase the potential for achieving specific performance goals while minimizing the potential for overtraining. Periodized resistance training plans are proposed to be superior to non-periodized training plans for enhancing maximal strength. The primary aim of this study was to examine the previous literature comparing periodized resistance training plans to non-periodized resistance training plans and determine a quantitative estimate of effect on maximal strength. All studies included in the meta-analysis met the following inclusion criteria: (1) peer-reviewed publication; (2) published in English; (3) comparison of a periodized resistance training group to a non-periodized resistance training group; (4) maximal strength measured by 1-repetition maximum (1RM) squat, bench press, or leg press. Data were extracted and independently coded by two authors. Random-effects models were used to aggregate a mean effect size (ES), 95% confidence intervals (CIs) and potential moderators. The cumulative results of 81 effects gathered from 18 studies published between 1988 and 2015 indicated that the magnitude of improvement in 1RM following periodized resistance training was greater than non-periodized resistance training (ES = 0.43, 95% CI 0.27-0.58; P < 0.001). Periodization model (β = 0.51; P = 0.0010), training status (β = -0.59; P = 0.0305), study length (β = 0.03; P = 0.0067), and training frequency (β = 0.46; P = 0.0123) were associated with a change in 1RM. These results indicate that undulating programs were more favorable for strength gains. Improvements in 1RM were greater among untrained participants. Additionally, higher training frequency and longer study length were associated with larger improvements in 1RM. These results suggest that periodized resistance training plans have a moderate effect on 1RM compared to non-periodized training plans. Variation in training stimuli appears to be vital for increasing maximal strength, and longer periods of higher training frequency may be preferred.

Strength and Endurance Training Prescription in Healthy and Frail Elderly

PubMed Central

Cadore, Eduardo Lusa; Pinto, Ronei Silveira; Bottaro, Martim; Izquierdo, Mikel

2014-01-01

Aging is associated with declines in the neuromuscular and cardiovascular systems, resulting in an impaired capacity to perform daily activities. Frailty is an age-associated biological syndrome characterized by decreases in the biological functional reserve and resistance to stressors due to changes in several physiological systems, which puts older individuals at special risk of disability. To counteract the neuromuscular and cardiovascular declines associated with aging, as well as to prevent and treat the frailty syndrome, the strength and endurance training seems to be an effective strategy to improve muscle hypertrophy, strength and power output, as well as endurance performance. The first purpose of this review was discuss the neuromuscular adaptations to strength training, as well as the cardiovascular adaptations to endurance training in healthy and frail elderly subjects. In addition, the second purpose of this study was investigate the concurrent training adaptations in the elderly. Based on the results found, the combination of strength and endurance training (i.e., concurrent training) performed at moderate volume and moderate to high intensity in elderly populations is the most effective way to improve both neuromuscular and cardiorespiratory functions. Moreover, exercise interventions that include muscle power training should be prescribed to frail elderly in order to improve the overall physical status of this population and prevent disability. PMID:24900941

The Effect of Shoulder Plyometric Training on Amortization Time and Upper-Extremity Kinematics.

PubMed

Swanik, Kathleen A; Thomas, Stephen J; Struminger, Aaron H; Bliven, Kellie C Huxel; Kelly, John D; Swanik, Charles B

2016-12-01

Plyometric training is credited with providing benefits in performance and dynamic restraint. However, limited prospective data exist quantifying kinematic adaptations such as amortization time, glenohumeral rotation, and scapulothoracic position, which may underlie the efficacy of plyometric training for upper-extremity rehabilitation or performance enhancement. To measure upper-extremity kinematics and plyometric phase times before and after an 8-wk upper-extremity strength- and plyometric-training program. Randomized pretest-posttest design. Research laboratory. 40 recreationally active men (plyometric group, age 20.43 ± 1.40 y, height 180.00 ± 8.80 cm, weight 73.07 ± 7.21 kg; strength group, age 21.95 ± 3.40 y, height 173.98 ± 11.91 cm, weight 74.79 ± 13.55 kg). Participants were randomly assigned to either a strength-training group or a strength- and plyometric-training group. Each participant performed the assigned training for 8 wk. Dynamic and static glenohumeral and scapular-rotation measurements were taken before and after the training programs. Dynamic measurement of scapular rotation and time spent in each plyometric phase (concentric, eccentric, and amortization) during a ball-toss exercise were recorded while the subjects were fitted with an electromagnetic tracking system. Static measures included scapular upward rotation at 3 different glenohumeral-abduction angles, glenohumeral internal rotation, and glenohumeral external rotation. Posttesting showed that both groups significantly decreased the time spent in the amortization, concentric, and eccentric phases of a ball-toss exercise (P < .01). Both groups also exhibited significantly decreased static external rotation and increased dynamic scapular upward rotation after the training period (P < .01). The only difference between the training protocols was that the plyometric-training group exhibited an increase in internal rotation that was not present in the strength-training group (P < .01). These findings support the use of both upper-extremity plyometrics and strength training for reducing commonly identified upper-extremity-injury risk factors and improving upper-extremity performance.

High- and Low-Load Resistance Training: Interpretation and Practical Application of Current Research Findings.

PubMed

Fisher, James; Steele, James; Smith, Dave

2017-03-01

Our current state of knowledge regarding the load (lighter or heavier) lifted in resistance training programmes that will result in 'optimal' strength and hypertrophic adaptations is unclear. Despite this, position stands and recommendations are made based on, we propose, limited evidence to lift heavier weights. Here we discuss the state of evidence on the impact of load and how it, as a single variable, stimulates adaptations to take place and whether evidence for recommending heavier loads is available, well-defined, currently correctly interpreted or has been overlooked. Areas of discussion include electromyography amplitude, in vivo and in vitro methods of measuring hypertrophy, and motor schema and skill acquisition. The present piece clarifies to trainers and trainees the impact of these variables by discussing interpretation of synchronous and sequential motor unit recruitment and revisiting the size principle, poor agreement between whole-muscle cross-sectional area (CSA) and biopsy-determined changes in myofibril CSA, and neural adaptations around task specificity. Our opinion is that the practical implications of being able to self-select external load include reducing the need for specific facility memberships, motivating older persons or those who might be less confident using heavy loads, and allowing people to undertake home- or field-based resistance training intervention strategies that might ultimately improve exercise adherence.

Mindfulness Training: Worthwhile as a Means to Enhance First Responder Crisis Decision Making

DTIC Science & Technology

2016-09-01

attention training , mindfulness-based mind fitness training , strength training for attention and resilience in ROTC cadets 15. NUMBER OF PAGES 127...situational awareness SIY search inside yourself program STARR strength training for attention and resilience in ROTC USAF United States Air Force...biochemical evidence in the argument for MT training , branding mindfulness, and MT with terms that would tend to be attractive to first responders, crafting

Quantitative Biology of Exercise-Induced Signal Transduction Pathways.

PubMed

Liu, Timon Cheng-Yi; Liu, Gang; Hu, Shao-Juan; Zhu, Ling; Yang, Xiang-Bo; Zhang, Quan-Guang

2017-01-01

Exercise is essential in regulating energy metabolism. Exercise activates cellular, molecular, and biochemical pathways with regulatory roles in training response adaptation. Among them, endurance/strength training of an individual has been shown to activate its respective signal transduction pathways in skeletal muscle. This was further studied from the viewpoint of quantitative difference (QD). For the mean values, [Formula: see text], of two sets of data, their QD is defined as [Formula: see text] ([Formula: see text]). The function-specific homeostasis (FSH) of a function of a biosystem is a negative-feedback response of the biosystem to maintain the function-specific conditions inside the biosystem so that the function is perfectly performed. A function in/far from its FSH is called a normal/dysfunctional function. A cellular normal function can resist the activation of other signal transduction pathways so that there are normal function-specific signal transduction pathways which full activation maintains the normal function. An acute endurance/strength training may be dysfunctional, but its regular training may be normal. The normal endurance/strength training of an individual may resist the activation of other signal transduction pathways in skeletal muscle so that there may be normal endurance/strength training-specific signal transduction pathways (NEPs/NSPs) in skeletal muscle. The endurance/strength training may activate NSPs/NEPs, but the QD from the control is smaller than 0.80. The simultaneous activation of both NSPs and NEPs may enhance their respective activation, and the QD from the control is larger than 0.80. The low level laser irradiation pretreatment of rats may promote the activation of NSPs in endurance training skeletal muscle. There may be NEPs/NSPs in skeletal muscle trained by normal endurance/strength training.

Treadmill Training or Progressive Strength Training to Improve Walking in People with Multiple Sclerosis? A Randomized Parallel Group Trial.

PubMed

Braendvik, Siri Merete; Koret, Teija; Helbostad, Jorunn L; Lorås, Håvard; Bråthen, Geir; Hovdal, Harald Olav; Aamot, Inger Lise

2016-12-01

The most effective treatment approach to improve walking in people with multiple sclerosis (MS) is not known. The aim of this trial was to assess the efficacy of treadmill training and progressive strength training on walking in people with MS. A single blinded randomized parallel group trial was carried out. Eligible participants were adults with MS with Expanded Disability Status Scale score ≤6. A total of 29 participants were randomized and 28 received the allocated exercise intervention, treadmill (n = 13) or strength training (n = 15). Both groups exercised 30 minutes, three times a week for 8 weeks. Primary outcome was The Functional Ambulation Profile evaluated by the GAITRite walkway. Secondary outcomes were walking work economy and balance control during walking, measured by a small lightweight accelerometer connected to the lower back. Testing was performed at baseline and the subsequent week after completion of training. Two participants were lost to follow-up, and 11 (treadmill) and 15 (strength training) were left for analysis. The treadmill group increased their Functional Ambulation Profile score significantly compared with the strength training group (p = .037). A significant improvement in walking work economy (p = .024) and a reduction of root mean square of vertical acceleration (p = .047) also favoured the treadmill group. The results indicate that task-specific training by treadmill walking is a favourable approach compared with strength training to improve walking in persons with mild and moderate MS. Implications for Physiotherapy practice, this study adds knowledge for the decision of optimal treatment approaches in people with MS. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Biochemical changes in response to intensive resistance exercise training in the elderly.

PubMed

Bautmans, Ivan; Njemini, Rose; Vasseur, Sabine; Chabert, Hans; Moens, Lisa; Demanet, Christian; Mets, Tony

2005-01-01

It is assumed that low-grade inflammation, characterized by increased circulating IL-6 and TNF-alpha, is related to the development of sarcopenia. Physical exercise, especially high intensity resistance training, has been shown to be effective in restoring the strength deficit in the elderly. Intensive exercise is accompanied by significant release of IL-6 and TNF-alpha into the blood circulation, but does not result in muscle wasting. Exercise-induced changes in heat-shock protein (Hsp), responsible for cellular protection during stressful situations, might interfere with the acute phase reaction and muscle adaptation. To investigate if intensive strength training in elderly persons induces changes in Hsp70 expression, and if these changes are related to changes in the acute phase reaction or muscle adaptation. 31 elderly persons (aged 68.4+/-5.4 years) performed 6 weeks' intensive strength training. At baseline and after 6 weeks, muscle strength, functional performance (physical activity profile, 6-min walk, 30- second chair stand, grip strength, chair sit & reach and back scratch), linear isokinetic leg extension, circulating IL-6, TNF-alpha, IL-10 and TGF-beta, and Hsp70 in monocytes (M) and lymphocytes (L) immediately after sampling (IAS), after incubation at 37 and 42 degrees C were determined. In 12 participants, cytokines were determined in untrained and trained conditions before and after a single training session. After 6 weeks' training, muscle strength and functional performance improved significantly, together with decreased Hsp70 IAS and Hsp70 37 degrees C and increased Hsp70 42 degrees C (all p<0.05). Strength gains correlated positively with baseline Hsp70 37 degrees C and training-induced changes of Hsp70 42 degrees C in M and L. In an untrained condition, training induced an increase of IL-6 (p<0.05) and a tendency of IL-10 to decrease (p=0.06). In a trained condition the decrease of IL-10 disappeared. Baseline physical activity and 6-min walk distance correlated negatively with circulating IL-6 (p<0.05); except for a negative correlation between TGF-beta and Hsp70 37 degrees C L (p<0.05), no significant relationships were found between cytokines and Hsp70. After the training program, Hsp70 37 degrees C was negatively related to circulating TNF-alpha, IL-10 and TGF-beta. Strength training in the elderly induces changes in Hsp70 expression, associated to strength gains and circulating cytokines. Copyright (c) 2005 S. Karger AG, Basel.

Combined resistance and endurance exercise training improves arterial stiffness, blood pressure, and muscle strength in postmenopausal women.

PubMed

Figueroa, Arturo; Park, Song Y; Seo, Dae Y; Sanchez-Gonzalez, Marcos A; Baek, Yeong H

2011-09-01

Menopause is associated with increased arterial stiffness and reduced muscle strength. Combined resistance (RE) and endurance (EE) exercise training can decrease brachial-ankle pulse wave velocity (baPWV), an index of arterial stiffness, in young men. We tested the hypothesis that combined circuit RE and EE training would improve baPWV, blood pressure (BP), and muscle strength in postmenopausal women. Twenty-four postmenopausal women (age 47-68 y) were randomly assigned to a "no exercise" control (n = 12) or to combined exercise training (EX; n = 12) group. The EX group performed concurrent circuit RE training followed by EE training at 60% of the predicted maximal heart rate (HR) 3 days per week. Brachial systolic BP, diastolic BP, mean arterial pressure, baPWV, HR, and dynamic and isometric muscle strength were measured before and after the 12-week study. Mean ± SE baPWV (-0.8 ± 0.2 meters/s), systolic BP (-6.0 ± 1.9 mm Hg), diastolic BP (-4.8 ± 1.7 mm Hg), HR (-4.0 ± 1.0 beats/min), and mean arterial pressure (-5.1 ± 1.6 mm Hg) decreased (P < 0.05), whereas dynamic leg strength (5.1 ± 1.0 vs 0.6 ± 1.0 kg for the EX and control groups, respectively) and isometric handgrip strength (2.8 ± 0.7 vs -0.6 ± 1.2 kg) increased (P < 0.05) in the EX group but not in the control group. Our findings indicate that a 12-week moderate-intensity combined circuit RE and EE training improves arterial stiffness, hemodynamics, and muscle strength in previously sedentary postmenopausal women. This study provides evidence that combined training may have important health implications for the prevention of hypertension and frailty in postmenopausal women.

Effect of an herbal/botanical supplement on strength, balance, and muscle function following 12-weeks of resistance training: a placebo controlled study

PubMed Central

2014-01-01

Background StemSport (SS; StemTech International, Inc. San Clemente, CA) contains a proprietary blend of the botanical Aphanizomenon flos-aquae and several herbal antioxidant and anti-inflammatory substances. SS has been purported to accelerate tissue repair and restore muscle function following resistance exercise. Here, we examine the effects of SS supplementation on strength adaptations resulting from a 12-week resistance training program in healthy young adults. Methods Twenty-four young adults (16 males, 8 females, mean age = 20.5 ± 1.9 years, mass = 70.9 ± 11.9 kg, stature = 176.6 ± 9.9 cm) completed the twelve week training program. The study design was a double-blind, placebo controlled parallel group trial. Subjects either received placebo or StemSport supplement (SS; mg/day) during the training. 1-RM bench press, 1-RM leg press, vertical jump height, balance (star excursion and center of mass excursion), isokinetic strength (elbow and knee flexion/extension) and perception of recovery were measured at baseline and following the 12-week training intervention. Results Resistance training increased 1-RM strength (p < 0.008), vertical jump height (p < 0.03), and isokinetic strength (p < 0.05) in both SS and placebo groups. No significant group-by-time interactions were observed (all p-values >0.10). Conclusions These data suggest that compared to placebo, the SS herbal/botanical supplement did not enhance training induced adaptations to strength, balance, and muscle function above strength training alone. PMID:24910543

Strength training for the warfighter.

PubMed

Kraemer, William J; Szivak, Tunde K

2012-07-01

Optimizing strength training for the warfighter is challenged by past training philosophies that no longer serve the modern warfighter facing the "anaerobic battlefield." Training approaches for integration of strength with other needed physical capabilities have been shown to require a periodization model that has the flexibility for changes and is able to adapt to ever-changing circumstances affecting the quality of workouts. Additionally, sequencing of workouts to limit over-reaching and development of overtraining syndromes that end in loss of duty time and injury are paramount to long-term success. Allowing adequate time for rest and recovery and recognizing the negative influences of extreme exercise programs and excessive endurance training will be vital in moving physical training programs into a more modern perspective as used by elite strength-power anaerobic athletes in sports today. Because the warfighter is an elite athlete, it is time that training approaches that are scientifically based are updated within the military to match the functional demands of modern warfare and are given greater credence and value at the command levels. A needs analysis, development of periodized training modules, and individualization of programs are needed to optimize the strength of the modern warfighter. We now have the knowledge, professional coaches and nonprofit organization certifications with continuing education units, and modern training technology to allow this to happen. Ultimately, it only takes command decisions and implementation to make this possible.

Effects of Combined Aerobic-Strength Training vs Fitness Education Program in COPD Patients.

PubMed

Rinaldo, Nicoletta; Bacchi, Elisabetta; Coratella, Giuseppe; Vitali, Francesca; Milanese, Chiara; Rossi, Andrea; Schena, Federico; Lanza, Massimo

2017-11-01

We compared the effects of a new physical activity education program approach (EDU), based on a periodically supervised protocol of different exercise modalities vs traditionally supervised combined strength-endurance training (CT) on health-related factors in patients with stable chronic obstructive pulmonary disease (COPD). Twenty-eight COPD patients without comorbidities were randomly assigned to receive either EDU or CT. CT was continuously supervised to combine strength-endurance training; EDU was taught to progressively increase the rate of autonomous physical activity, through different training modalities such as Nordic walking, group classes and circuit training. Body composition, walking capacity, muscle strength, flexibility and balance, total daily energy expenditure and quality of life were evaluated at baseline, after 28 weeks training period (3d/week) and after a 14-week follow-up. No adverse events occurred during the interventions. After training, CT and EDU similarly improved walking capacity, body composition and quality of life. However, after 14 weeks of follow-up, such improvements were not maintained. Only in CT, muscle strength and flexibility improved after training but returned to baseline after follow-up. EDU, similar to CT, can effectively and safely improve health-related parameters in COPD patients. EDU could be an attractive alternative to traditional supervised training for improving quality of life in COPD patients. © Georg Thieme Verlag KG Stuttgart · New York.

Effects of hydraulic resistance circuit training on physical fitness components of potential relevance to +Gz tolerance.

PubMed

Jacobs, I; Bell, D G; Pope, J; Lee, W

1987-08-01

Recent studies carried out in the United States and Sweden have demonstrated that strength training can improve +Gz acceleration tolerance. Based on these findings, the Canadian Forces have introduced a training program for aircrew of high performance aircraft. This report describes the changes in physical fitness components considered relevant to +Gz tolerance after 12 weeks of training with this program. Prior to beginning training, 45 military personnel were tested, but only 20 completed a minimum of 24 training sessions. The following variables were measured in these 20 subjects before and after training: maximal strength of several large muscle groups during isokinetic contractions, maximal aerobic power and an endurance fitness index, maximal anaerobic power, anthropometric characteristics, and maximal expiratory pressure generated during exhalation. Training involved hydraulic resistance circuit training 2-4 times/week. The circuit consisted of 3 consecutive sets at each of 8 stations using Hydra-Gym equipment. The exercise:rest ratio was 20:40 s for the initial 4 training weeks and was then changed to 30:50. After training the changes in anthropometric measurements suggested that lean body mass was increased. Small, but significant, increases were also measured in muscle strength during bench press, biceps curls, squats, knee extension, and knee flexion. Neither maximal anaerobic power (i.e. muscular endurance) nor maximal expiratory pressure were changed after the training. Indices of endurance fitness were also increased in the present study. The relatively small increases in strength are probably due to the design of the exercise:rest ratio which resulted in improved strength and aerobic fitness.(ABSTRACT TRUNCATED AT 250 WORDS)

FAST CP: protocol of a randomised controlled trial of the efficacy of a 12-week combined Functional Anaerobic and Strength Training programme on muscle properties and mechanical gait deficiencies in adolescents and young adults with spastic-type cerebral palsy

PubMed Central

Gillett, Jarred G; Lichtwark, Glen A; Boyd, Roslyn N; Barber, Lee A

2015-01-01

Introduction Individuals with cerebral palsy (CP) have muscles that are smaller, weaker and more resistant to stretch compared to typically developing people. Progressive resistance training leads to increases in muscle size and strength. In CP, the benefits of resistance training alone may not transfer to improve other activities such as walking; however, the transfer of strength improvements to improved mobility may be enhanced by performing training that involves specific functional tasks or motor skills. This study aims to determine the efficacy of combined functional anaerobic and strength training in (1) influencing muscle strength, structure and function and (2) to determine if any changes in muscle strength and structure following training impact on walking ability and gross motor functional capacity and performance in the short (following 3 months of training) and medium terms (a further 3 months post-training). Methods and analysis 40 adolescents and young adults with CP will be recruited to undertake a 12-week training programme. The training programme will consist of 3×75 min sessions per week, made up of 5 lower limb resistance exercises and 2–3 functional anaerobic exercises per session. The calf muscles will be specifically targeted, as they are the most commonly impacted muscles in CP and are a key muscle group involved in walking. If, as we believe, muscle properties change following combined strength and functional training, there may be long-term benefits of this type of training in slowing the deterioration of muscle function in people with spastic-type CP. Ethics and dissemination Ethical approval has been obtained from the ethics committees at The University of Queensland (2014000066) and Children's Health Queensland (HREC/15/QRCH/30). The findings will be disseminated by publications in peer-reviewed journals, conferences and local research organisations’ media. Trial registration number Australian and New Zealand Clinical Trials Registry (ACTRN12614001217695). PMID:26116614

Post-exercise cold water immersion attenuates acute anabolic signalling and long-term adaptations in muscle to strength training

PubMed Central

Roberts, Llion A; Raastad, Truls; Markworth, James F; Figueiredo, Vandre C; Egner, Ingrid M; Shield, Anthony; Cameron-Smith, David; Coombes, Jeff S; Peake, Jonathan M

2015-01-01

Abstract We investigated functional, morphological and molecular adaptations to strength training exercise and cold water immersion (CWI) through two separate studies. In one study, 21 physically active men strength trained for 12 weeks (2 days per week), with either 10 min of CWI or active recovery (ACT) after each training session. Strength and muscle mass increased more in the ACT group than in the CWI group (P < 0.05). Isokinetic work (19%), type II muscle fibre cross-sectional area (17%) and the number of myonuclei per fibre (26%) increased in the ACT group (all P < 0.05), but not the CWI group. In another study, nine active men performed a bout of single-leg strength exercises on separate days, followed by CWI or ACT. Muscle biopsies were collected before and 2, 24 and 48 h after exercise. The number of satellite cells expressing neural cell adhesion molecule (NCAM) (10−30%) and paired box protein (Pax7) (20−50%) increased 24–48 h after exercise with ACT. The number of NCAM+ satellite cells increased 48 h after exercise with CWI. NCAM+- and Pax7+-positive satellite cell numbers were greater after ACT than after CWI (P < 0.05). Phosphorylation of p70S6 kinaseThr421/Ser424 increased after exercise in both conditions but was greater after ACT (P < 0.05). These data suggest that CWI attenuates the acute changes in satellite cell numbers and activity of kinases that regulate muscle hypertrophy, which may translate to smaller long-term training gains in muscle strength and hypertrophy. The use of CWI as a regular post-exercise recovery strategy should be reconsidered. Key points Cold water immersion is a popular strategy to recover from exercise. However, whether regular cold water immersion influences muscle adaptations to strength training is not well understood. We compared the effects of cold water immersion and active recovery on changes in muscle mass and strength after 12 weeks of strength training. We also examined the effects of these two treatments on hypertrophy signalling pathways and satellite cell activity in skeletal muscle after acute strength exercise. Cold water immersion attenuated long term gains in muscle mass and strength. It also blunted the activation of key proteins and satellite cells in skeletal muscle up to 2 days after strength exercise. Individuals who use strength training to improve athletic performance, recover from injury or maintain their health should therefore reconsider whether to use cold water immersion as an adjuvant to their training. PMID:26174323

Effects of Different Resistance Training Protocols on Upper-Body Strength and Endurance Development in Children.

ERIC Educational Resources Information Center

Faigenbaum, Avery D.; Loud, Rita LaRosa; O'Connell, Jill; Glover, Scott; O'Connell, Jason; Westcott, Wayne L.

2001-01-01

Examined the effects of four resistance training protocols on upper body strength and muscular endurance development in children. Untrained children trained twice per week for 8 weeks, using general conditioning exercises and different upper-body conditioning protocols. Results indicated that higher-repetition training protocols enhanced…

Effects of cross-education on the muscle after a period of unilateral limb immobilization using a shoulder sling and swathe.

PubMed

Magnus, Charlene R A; Barss, Trevor S; Lanovaz, Joel L; Farthing, Jonathan P

2010-12-01

The purpose of this study was to apply cross-education during 4 wk of unilateral limb immobilization using a shoulder sling and swathe to investigate the effects on muscle strength, muscle size, and muscle activation. Twenty-five right-handed participants were assigned to one of three groups as follows: the Immob + Train group wore a sling and swathe and strength trained (n = 8), the Immob group wore a sling and swathe and did not strength train (n = 8), and the Control group received no treatment (n = 9). Immobilization was applied to the nondominant (left) arm. Strength training consisted of maximal isometric elbow flexion and extension of the dominant (right) arm 3 days/wk. Torque (dynamometer), muscle thickness (ultrasound), maximal voluntary activation (interpolated twitch), and electromyography (EMG) were measured. The change in right biceps and triceps brachii muscle thickness [7.0 ± 1.9 and 7.1 ± 2.2% (SE), respectively] was greater for Immob + Train than Immob (0.4 ± 1.2 and -1.9 ± 1.7%) and Control (0.8 ± 0.5 and 0.0 ± 1.1%, P < 0.05). Left biceps and triceps brachii muscle thickness for Immob + Train (2.2 ± 0.7 and 3.4 ± 2.1%, respectively) was significantly different from Immob (-2.8 ± 1.1 and -5.2 ± 2.7%, respectively, P < 0.05). Right elbow flexion strength for Immob + Train (18.9 ± 5.5%) was significantly different from Immob (-1.6 ± 4.0%, P < 0.05). Right and left elbow extension strength for Immob + Train (68.1 ± 25.9 and 32.2 ± 9.0%, respectively) was significantly different from the respective limb of Immob (1.3 ± 7.7 and -6.1 ± 7.8%) and Control (4.7 ± 4.7 and -0.2 ± 4.5%, P < 0.05). Immobilization in a sling and swathe decreased strength and muscle size but had no effect on maximal voluntary activation or EMG. The cross-education effect on the immobilized limb was greater after elbow extension training. This study suggests that strength training the nonimmobilized limb benefits the immobilized limb for muscle size and strength.

Training Visual Imagery: Improvements of Metacognition, but not Imagery Strength

PubMed Central

Rademaker, Rosanne L.; Pearson, Joel

2012-01-01

Visual imagery has been closely linked to brain mechanisms involved in perception. Can visual imagery, like visual perception, improve by means of training? Previous research has demonstrated that people can reliably evaluate the vividness of single episodes of imagination – might the metacognition of imagery also improve over the course of training? We had participants imagine colored Gabor patterns for an hour a day, over the course of five consecutive days, and again 2 weeks after training. Participants rated the subjective vividness and effort of their mental imagery on each trial. The influence of imagery on subsequent binocular rivalry dominance was taken as our measure of imagery strength. We found no overall effect of training on imagery strength. Training did, however, improve participant’s metacognition of imagery. Trial-by-trial ratings of vividness gained predictive power on subsequent rivalry dominance as a function of training. These data suggest that, while imagery strength might be immune to training in the current context, people’s metacognitive understanding of mental imagery can improve with practice. PMID:22787452

The effects of training by virtual reality or gym ball on pelvic floor muscle strength in postmenopausal women: a randomized controlled trial.

PubMed

Martinho, Natalia M; Silva, Valéria R; Marques, Joseane; Carvalho, Leonardo C; Iunes, Denise H; Botelho, Simone

2016-03-22

To evaluate the effectiveness of abdominopelvic training by virtual reality compared to pelvic floor muscle training (PFMT) using a gym ball (a previously tested and efficient protocol) on postmenopausal women's pelvic floor muscle (PFM) strength. A randomized controlled trial was conducted with 60 postmenopausal women, randomly allocated into two groups: Abdominopelvic training by virtual reality - APT_VR (n=30) and PFMT using a gym ball - PFMT_GB (n=30). Both types of training were supervised by the same physical therapist, during 10 sessions each, for 30 minutes. The participants' PFM strength was evaluated by digital palpation and vaginal dynamometry, considering three different parameters: maximum strength, average strength and endurance. An intention-to-treat approach was used to analyze the participants according to original groups. No significant between-group differences were observed in most analyzed parameters. The outcome endurance was higher in the APT_VR group (p=0.003; effect size=0.89; mean difference=1.37; 95% CI=0.46 to 2.28). Both protocols have improved the overall PFM strength, suggesting that both are equally beneficial and can be used in clinical practice. Muscle endurance was higher in patients who trained using virtual reality.

The effects of training by virtual reality or gym ball on pelvic floor muscle strength in postmenopausal women: a randomized controlled trial

PubMed Central

Martinho, Natalia M.; Silva, Valéria R.; Marques, Joseane; Carvalho, Leonardo C.; Iunes, Denise H.; Botelho, Simone

2016-01-01

ABSTRACT Objective To evaluate the effectiveness of abdominopelvic training by virtual reality compared to pelvic floor muscle training (PFMT) using a gym ball (a previously tested and efficient protocol) on postmenopausal women’s pelvic floor muscle (PFM) strength. Method A randomized controlled trial was conducted with 60 postmenopausal women, randomly allocated into two groups: Abdominopelvic training by virtual reality – APT_VR (n=30) and PFMT using a gym ball – PFMT_GB (n=30). Both types of training were supervised by the same physical therapist, during 10 sessions each, for 30 minutes. The participants’ PFM strength was evaluated by digital palpation and vaginal dynamometry, considering three different parameters: maximum strength, average strength and endurance. An intention-to-treat approach was used to analyze the participants according to original groups. Results No significant between-group differences were observed in most analyzed parameters. The outcome endurance was higher in the APT_VR group (p=0.003; effect size=0.89; mean difference=1.37; 95% CI=0.46 to 2.28). Conclusion Both protocols have improved the overall PFM strength, suggesting that both are equally beneficial and can be used in clinical practice. Muscle endurance was higher in patients who trained using virtual reality. PMID:27437716

Effects of exercise training using resistance bands on glycaemic control and strength in type 2 diabetes mellitus: a meta-analysis of randomised controlled trials.

PubMed

McGinley, Samantha K; Armstrong, Marni J; Boulé, Normand G; Sigal, Ronald J

2015-04-01

Resistance exercise using free weights or weight machines improves glycaemic control and strength in people with type 2 diabetes. Resistance band training is potentially less expensive and more accessible, but the effects of resistance band training on glycaemic control and strength in this population are not well understood. This paper aims to systematically review and meta-analyse the effect of resistance band training on haemoglobin A1c (HbA1c) and strength in adults with type 2 diabetes. Database searches were performed in August 2013 (MEDLINE, SPORTDiscus, EMBASE, and CINAHL). Reference lists of eligible articles were hand-searched for additional studies. Randomised trials evaluating the effects of resistance band training in adults with type 2 diabetes on HbA1c or objectively measured strength were selected. Baseline and post-intervention HbA1c and strength were extracted for the intervention and control groups. Details of the exercise interventions and methodological quality were collected. Seven trials met inclusion criteria. Post-intervention-weighted mean HbA1c was nonsignificantly lower in exercise groups compared to control groups [weighted mean difference (WMD) = -0.18 percentage points (-1.91 mmol/mol); P = 0.27]. Post-intervention strength was significantly higher in the exercise groups compared to the control groups in the lower extremities (WMD = 21.90 kg; P < 0.0001), but not in the upper extremities (WMD = 2.27 kg; P = 0.13) or handgrip (WMD = 1.98 kg; P = 0.46). All trials were small and had methodological limitations. Resistance band training did not significantly affect HbA1c, upper extremity, or handgrip strength but significantly increased the strength of the lower extremities in people with type 2 diabetes.

Strength and conditioning practices in rowing.

PubMed

Gee, Thomas I; Olsen, Peter D; Berger, Nicolas J; Golby, Jim; Thompson, Kevin G

2011-03-01

There is limited published research on the practices of strength and conditioning (S &C) coaches in Great Britain. Information about training program design would be useful in developing models of good practice and ecologically valid intervention studies. The aim of this research was to quantify the training practices of coaches responsible for the S&C of rowing athletes. A questionnaire was developed that consisted of 6 sections: (a) personal details, (b) physical testing, (c) strength and power development, (d) flexibility development, (e) unique aspects of the program, and (f) any further relevant comments regarding the athletes prescribed training program. Twenty-two rowing and 10 S&C coaches with an average of 10.5 ± 7.2 years' experience agreed to complete the questionnaire. Approximately, 34% coached rowers of Olympic standard, 34% coached national standard, 3% coached regional standard, 19% coached club standard, and 10% coached university standard rowers. All coaches agreed that strength training enhanced rowing performance and the majority (74%) indicated that athletes' strength trained 2-3 times a week. Almost all coaches (94%) reported their rowers performed strength training, with 81% using Olympic lifting, and 91% employing a periodized training model. The clean (63%) and squat (27%) were rated the most important prescribed exercises. Approximately 50% of coaches used plyometrics such as depth jumps, box drills, and standing jumps. Ninety-four percent indicated they conducted physical testing on their rowers, typically assessing cardiovascular endurance (80%), muscular power (70%), muscular strength (70%), and anaerobic capacity (57%). This research represents the only published survey to date on the S&C practices in rowing within Great Britain.

Effects of yoga, strength training and advice on back pain: a randomized controlled trial.

PubMed

Brämberg, Elisabeth Björk; Bergström, Gunnar; Jensen, Irene; Hagberg, Jan; Kwak, Lydia

2017-03-29

Among the working population, non-specific low-back pain and neck pain are one of the most common reasons for sickness absenteeism. The aim was to evaluate the effects of an early intervention of yoga - compared with strength training or evidence-based advice - on sickness absenteeism, sickness presenteeism, back and neck pain and disability among a working population. A randomized controlled trial was conducted on 159 participants with predominantly (90%) chronic back and neck pain. After screening, the participants were randomized to kundalini yoga, strength training or evidence-based advice. Primary outcome was sickness absenteeism. Secondary outcomes were sickness presenteeism, back and neck pain and disability. Self-reported questionnaires and SMS text messages were completed at baseline, 6 weeks, 6 and 12 months. The results did not indicate that kundalini yoga and strength training had any statistically significant effects on the primary outcome compared with evidence-based advice. An interaction effect was found between adherence to recommendations and sickness absenteeism, indicating larger significant effects among the adherers to kundalini yoga versus evidence-based advice: RR = 0.47 (CI 0.30; 0.74, p = 0.001), strength training versus evidence-based advice: RR = 0.60 (CI 0.38; 0.96, p = 0.032). Some significant differences were also found for the secondary outcomes to the advantage of kundalini yoga and strength training. Guided exercise in the forms of kundalini yoga or strength training does not reduce sickness absenteeism more than evidence-based advice alone. However, secondary analyses reveal that among those who pursue kundalini yoga or strength training at least two times a week, a significantly reduction in sickness absenteeism was found. Methods to increase adherence to treatment recommendations should be further developed and applied in exercise interventions. Clinicaltrials.gov NCT01653782, date of registration: June, 28, 2012, retrospectively registered.

Effects of dry-land vs. resisted- and assisted-sprint exercises on swimming sprint performances.

PubMed

Girold, Sébastien; Maurin, Didier; Dugué, Benoit; Chatard, Jean-Claude; Millet, Grégoire

2007-05-01

This study was undertaken to compare the effects of dry-land strength training with a combined in-water resisted- and assisted-sprint program in swimmer athletes. Twenty-one swimmers from regional to national level participated in this study. They were randomly assigned to 3 groups: the strength (S) group that was involved in a dry-land strength training program where barbells were used, the resisted- and assisted-sprint (RAS) group that got involved in a specific water training program where elastic tubes were used to generate resistance and assistance while swimming, and the control (C) group which was involved in an aerobic cycling program. During 12 weeks, the athletes performed 6 training sessions per week on separate days. All of them combined the same aerobic dominant work for their basic training in swimming and running with their specific training. Athletes were evaluated 3 times: before the training program started, after 6 weeks of training, and at the end of the training program. The outcome values were the strength of the elbow flexors and extensors evaluated using an isokinetic dynamometer, and the speed, stroke rate, stroke length, and stroke depth observed during a 50-meter sprint. No changes were observed after 6 weeks of training. At the end of the training period, we observed significant increases in swimming velocity, and strength of elbow flexors and extensors both in the S and RAS groups. However, stroke depth decreased both in the S and RAS groups. Stroke rate increased in the RAS but not in the S group. However, no significant differences in the swimming performances between the S and RAS groups were observed. No significant changes occurred in C. Altogether, programs combining swimming with dry-land strength or with in-water resisted- and assisted-sprint exercises led to a similar gain in sprint performance and are more efficient than traditional swimming training methods alone.

Variable Resistance Training Promotes Greater Strength and Power Adaptations Than Traditional Resistance Training in Elite Youth Rugby League Players.

PubMed

Rivière, Maxence; Louit, Loic; Strokosch, Alasdair; Seitz, Laurent B

2017-04-01

Rivière, M, Louit, L, Strokosch, A, and Seitz, LB. Variable resistance training promotes greater strength and power adaptations than traditional resistance training in elite youth rugby league players. J Strength Cond Res 31(4): 947-955, 2017-The purpose of this study was to examine the strength, velocity, and power adaptations in youth rugby league players in response to a variable resistance training (VRT) or traditional free-weight resistance training (TRAD) intervention. Sixteen elite youth players were assigned to a VRT or TRAD group and completed 2 weekly upper- and lower-body strength and power sessions for 6 weeks. Training programs were identical except that the VRT group trained the bench press exercise with 20% of the prescribed load coming from elastic bands. Bench press 1 repetition maximum (1RM) and bench press mean velocity and power at 35, 45, 65, 75, and 85% of 1RM were measured before and after the training intervention, and the magnitude of the changes was determined using effect sizes (ESs). The VRT group experienced larger increases in both absolute (ES = 0.46 vs. 0.20) and relative (ES = 0.41 vs. 0.19) bench press 1RM. Similar results were observed for mean velocity as well as both absolute and relative mean power at 35, 45, 65, 75, and 85% of 1RM. Furthermore, both groups experienced large gains in both velocity and power in the heavier loads but small improvements in the lighter loads. The improvements in both velocity and power against the heavier loads were larger for the VRT group, whereas smaller differences existed between the 2 groups in the lighter loads. Variable resistance training using elastic bands may offer a greater training stimulus than traditional free-weight resistance training to improve upper-body strength, velocity, and power in elite youth rugby league players.

Neither load nor systemic hormones determine resistance training-mediated hypertrophy or strength gains in resistance-trained young men.

PubMed

Morton, Robert W; Oikawa, Sara Y; Wavell, Christopher G; Mazara, Nicole; McGlory, Chris; Quadrilatero, Joe; Baechler, Brittany L; Baker, Steven K; Phillips, Stuart M

2016-07-01

We reported, using a unilateral resistance training (RT) model, that training with high or low loads (mass per repetition) resulted in similar muscle hypertrophy and strength improvements in RT-naïve subjects. Here we aimed to determine whether the same was true in men with previous RT experience using a whole-body RT program and whether postexercise systemic hormone concentrations were related to changes in hypertrophy and strength. Forty-nine resistance-trained men (23 ± 1 yr, mean ± SE) performed 12 wk of whole-body RT. Subjects were randomly allocated into a higher-repetition (HR) group who lifted loads of ∼30-50% of their maximal strength (1RM) for 20-25 repetitions/set (n = 24) or a lower-repetition (LR) group (∼75-90% 1RM, 8-12 repetitions/set, n = 25), with all sets being performed to volitional failure. Skeletal muscle biopsies, strength testing, dual-energy X-ray absorptiometry scans, and acute changes in systemic hormone concentrations were examined pretraining and posttraining. In response to RT, 1RM strength increased for all exercises in both groups (P < 0.01), with only the change in bench press being significantly different between groups (HR, 9 ± 1, vs. LR, 14 ± 1 kg, P = 0.012). Fat- and bone-free (lean) body mass and type I and type II muscle fiber cross-sectional area increased following training (P < 0.01) with no significant differences between groups. No significant correlations between the acute postexercise rise in any purported anabolic hormone and the change in strength or hypertrophy were found. In congruence with our previous work, acute postexercise systemic hormonal rises are not related to or in any way indicative of RT-mediated gains in muscle mass or strength. Our data show that in resistance-trained individuals, load, when exercises are performed to volitional failure, does not dictate hypertrophy or, for the most part, strength gains. Copyright © 2016 the American Physiological Society.

Effect of Low-Level Laser Therapy and Strength Training Protocol on Hand Grip by Dynamometry

PubMed Central

Barbosa, Rafael; Marcolino, Alexandre; Souza, Vitor; Bertolino, Guilherme; Fonseca, Marisa; Guirro, Rinaldo

2017-01-01

Introduction: The purpose of this study was to investigate the effect of low-level laser therapy (LLLT) – 660 nm and 904 nm - before grip strength protocol in healthy subjects. Methods: The study included 45 healthy volunteers with an average age of 22.7 (±1.4) years, subdivided into the following groups, control group: grip strength training associated with placebo LLLT; 660 nm group: LLLT (660 nm, 20 J/cm2, power of 30 mW, and beam area of 0.06 cm2, continuous, energy 1.2 J, and exposure time 40 seconds per point) before grip strength training and 904 nm group: LLLT (904 nm, 10 J/cm2, peak power of 70 W and 0.13 cm2 beam area, with pulsed beam 9.500 Hz and 30 seconds of exposure time per point and emitted energy 1.2 J) before grip strength training. The LLLT was timed to contact 10 points located in the region of the superficial and deep flexor muscles of the fingers, with a total energy of 12.0 J per session. For the strength training protocol, the volunteer exercised their fingers with the dominant hand on a small table, elbow flexed at 90°, forearm in neutral, using a light extension handle. The Oxford protocol was performed during four weeks. The grip strength was assessed using a dynamometer (Jamar™). The data were evaluated by the analysis of variance (ANOVA) statistical method. Results: In the comparison of intragroup evaluation, only the 904 nm group showed a difference compared to the baseline assessment after 4 weeks (P < 0.05), in the final intergroup evaluation, a difference was observed in the comparison between the control and 904 nm groups Conclusion: In conclusion, LLLT (904 nm) applied before resistance training was effective in gaining grip strength when compared to LLLT (660 nm) and isolated strength training after 4 weeks. PMID:29123629

A Systematic Review of Isometric Lingual Strength-Training Programs in Adults With and Without Dysphagia

PubMed Central

Zhang, Bin; Haines, Morgan B.; Kelchner, Lisa N.

2017-01-01

Purpose This systematic review summarizes the effects of isometric lingual strength training on lingual strength and swallow function in adult populations. Furthermore, it evaluates the designs of the reviewed studies and identifies areas of future research in isometric lingual strength training for dysphagia remediation. Method A comprehensive literature search of 3 databases and additional backward citation search identified 10 studies for inclusion in the review. The review reports and discusses the isometric-exercise intervention protocols, pre- and postintervention lingual-pressure data (maximum peak pressures and lingual-palatal pressures during swallowing), and oropharyngeal swallowing measures such as penetration-aspiration scales, oropharyngeal residue and duration, lingual volumes, and quality-of-life assessments. Results Studies reported gains in maximum peak lingual pressures following isometric lingual strength training for both healthy adults and select groups of individuals with dysphagia. However, due to the variability in study designs, it remains unclear whether strength gains generalize to swallow function. Conclusion Although isometric lingual strength training is a promising intervention for oropharyngeal dysphagia, the current literature is too variable to confidently report specific therapeutic benefits. Future investigations should target homogenous patient populations and use randomized controlled trials to determine the efficacy of this treatment for individuals with dysphagia. PMID:28282484

Promoting balance and strength in the middle-aged workforce.

PubMed

Granacher, U; Wick, C; Rueck, N; Esposito, C; Roth, R; Zahner, L

2011-01-01

The prevalence of sustaining fall-related injuries is high in the middle-aged workforce. Deficits in postural control/muscle strength represent important fall-risk factors. The objective of this study was to examine the impact of balance and strength training followed by detraining on postural control and muscle strength in the workforce. Thirty-two adults with sedentary office work participated in this study and were assigned to an intervention (age 56.0 ± 3.7 yrs) or a control group (age 55.5 ± 3.4 yrs). The intervention group participated in 8 weeks of balance and strength training conducted at the worksite, followed by 8 weeks of detraining. Tests included the measurement of (a) total centre of pressure (COP) displacements during one-legged standing, (b) gait velocity and stride-to-stride variability, (c) peak isometric/isokinetic torque and rate of torque development (RTD) of the plantar flexors, and (d) jumping height. After training, significant improvements in COP displacements, gait velocity, peak isometric/isokinetic torque, RTD, and jumping height were observed. During detraining, muscle strength deteriorated, whereas postural control improved. This fall-preventive training program conducted at the worksite proved to be feasible and effective. It is suggested that this training program should be permanently conducted to maintain/improve muscle strength. © Georg Thieme Verlag KG Stuttgart · New York.

Blood flow restricted resistance training in older adults at risk of mobility limitations.

PubMed

Cook, Summer B; LaRoche, Dain P; Villa, Michelle R; Barile, Hannah; Manini, Todd M

2017-12-01

High-load resistance training (HL) may be contraindicated in older adults due to pre-existing health conditions (e.g. osteoarthritis). Low-load blood flow restricted (BFR) resistance training offers an alternative to HL with potentially similar strength improvement. To compare muscle strength, cross-sectional area (CSA), physical function, and quality of life (QOL) following 12-weeks of HL or BFR training in older adults at risk of mobility limitations. Thirty-six males and females (mean: 75.6years 95% confidence interval: [73.4-78.5], 1.67m [1.64-1.70], 74.3kg [69.8-78.8]) were randomly assigned to HL (70% of one repetition maximum [1-RM]) or low-load BFR (30% 1-RM coupled with a vascular restriction) exercise for the knee extensors and flexors twice per week for 12weeks. A control (CON) group performed light upper body resistance and flexibility training. Muscle strength, CSA of the quadriceps, 400-m walking speed, Short Physical Performance Battery (SPPB), and QOL were assessed before, midway and after training. Within 6-weeks of HL training, increases in all strength measures and CSA were evident and the gains were significantly greater than the CON group (P<0.05). The BFR group had strength increases in leg extension and leg press 1-RM tests, but were significantly lower in leg extension isometric maximum voluntary contraction (MVC) and leg extension 1-RM than the HL group (P<0.01). At 12-weeks HL and BFR training did not differ in MVC (P=0.14). Walking speed increased 4% among all training groups (P<0.01) and no changes were observed for overall SPPB score and QOL (P>0.05). Both training programs resulted in muscle CSA improvements and HL training had more pronounced strength gains than BFR training after 6-weeks and were more similar to BFR after 12-weeks of training. These changes in both groups did not transfer to improvements in QOL, SPPB, and walking speed. Since both programs result in strength and CSA gains, albeit at different rates, future research should consider using a combination of HL and BFR training in older adults with profound muscle weakness and mobility limitations. Copyright © 2017 Elsevier Inc. All rights reserved.

The strength and conditioning practices of strongman competitors.

PubMed

Winwood, Paul W; Keogh, Justin W L; Harris, Nigel K

2011-11-01

This study describes the results of a survey of the strength and conditioning practices of strongman competitors. A 65-item online survey was completed by 167 strongman competitors. The subject group included 83 local, 65 national, and 19 international strongman competitors. The survey comprised 3 main areas of enquiry: (a) exercise selection, (b) training protocols and organization, and (c) strongman event training. The back squat and conventional deadlift were reported as the most commonly used squat and deadlift (65.8 and 88.0%, respectively). Eighty percent of the subjects incorporated some form of periodization in their training. Seventy-four percent of subjects included hypertrophy training, 97% included maximal strength training, and 90% included power training in their training organization. The majority performed speed repetitions with submaximal loads in the squat and deadlift (59.9 and 61.1%, respectively). Fifty-four percent of subjects incorporated lower body plyometrics into their training, and 88% of the strongman competitors reported performing Olympic lifts as part of their strongman training. Seventy-eight percent of subjects reported that the clean was the most performed Olympic lift used in their training. Results revealed that 56 and 38% of the strongman competitors used elastic bands and chains in their training, respectively. The findings demonstrate that strongman competitors incorporate a variety of strength and conditioning practices that are focused on increasing muscular size, and the development of maximal strength and power into their conditioning preparation. The farmers walk, log press, and stones were the most commonly performed strongman exercises used in a general strongman training session by these athletes. These data provide information on the training practices required to compete in the sport of strongman.

Nutritional aspects of women strength athletes.

PubMed

Volek, J S; Forsythe, C E; Kraemer, W J

2006-09-01

Strength training elicits sports related and health benefits for both men and women. Although sexual dimorphism is observed in exercise metabolism, there is little information outlining the specific nutritional needs of women strength athletes. Many women athletes restrict energy intake, specifically fat consumption, in order to modify body composition, but this nutritional practice is often counter-productive. Compared to men, women appear to be less reliant on glycogen during exercise and less responsive to carbohydrate mediated glycogen synthesis during recovery. Female strength athletes may require more protein than their sedentary and endurance training counterparts to attain positive nitrogen balance and promote protein synthesis. Therefore, women strength athletes should put less emphasis on a very high carbohydrate intake and more emphasis on quality protein and fat consumption in the context of energy balance to enhance adaptations to training and improve general health. Attention to timing of nutrient ingestion, macronutrient quality, and dietary supplementation (for example, creatine) are briefly discussed as important components of a nutritionally adequate and effective strength training diet for women.

The effect of instability training on knee joint proprioception and core strength.

PubMed

Cuğ, Mutlu; Ak, Emre; Ozdemir, Recep Ali; Korkusuz, Feza; Behm, David G

2012-01-01

Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% respectively. The exercise group increased their trunk flexion peak torque/body weight ratios by 18.1% while the control group decreased by 0.4%. Knee proprioception (combined right and left joint repositioning) improved 44.7% from pre- to post-training (p = 0.0006) and persisted (21.5%) for 9 months post-training. In addition there was a side interaction with the position sense of the right knee at 9 months showing 32.1% (p = 0.03) less deviation from the reference angle than the right knee during pre-testing. An instability-training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength in previously untrained individuals performing this novel training stress which would contribute to general health. Key pointsAlthough traditional free weight resistance exercises have been recommended as most beneficial for improving strength and power in athletes (Behm et al., 2010b), an IT program using Swiss balls and body weight as a resistance may provide an alternative starting point for the sedentary untrained population.As it is well documented that force or strength is decreased when unbalanced (Behm et al., 2010b) and balance-training programs improve balance (Behm and Kean 2006), this type of instability RT program can provide significant adaptations to improve trunk strength especially with the untrained.This type of training should also be incorporated into a new program as the improvements in joint proprioception may help protect from joint injuries over a protracted period.The finding that improved joint proprioception persists for months after training should be emphasized to those individuals whose training is regularly or inconsistently interrupted.

Executive Summary From the National Strength and Conditioning Association's Second Blue Ribbon Panel on Military Physical Readiness: Military Physical Performance Testing.

PubMed

Nindl, Bradley C; Alvar, Brent A; R Dudley, Jason; Favre, Mike W; Martin, Gerard J; Sharp, Marilyn A; Warr, Brad J; Stephenson, Mark D; Kraemer, William J

2015-11-01

The National Strength and Conditioning Association's tactical strength and conditioning program sponsored the second Blue Ribbon Panel on military physical readiness: military physical performance testing, April 18-19, 2013, Norfolk, VA. This meeting brought together a total of 20 subject matter experts (SMEs) from the U.S. Air Force, Army, Marine Corps, Navy, and academia representing practitioners, operators, researchers, and policy advisors to discuss the current state of physical performance testing across the Armed Services. The SME panel initially rated 9 common military tasks (jumping over obstacles, moving with agility, carrying heavy loads, dragging heavy loads, running long distances, moving quickly over short distances, climbing over obstacles, lifting heavy objects, loading equipment) by the degree to which health-related fitness components (e.g., aerobic fitness, muscular strength, muscular endurance, flexibility, and body composition) and skill-related fitness components (e.g., muscular power, agility, balance, coordination, speed, and reaction time) were required to accomplish these tasks. A scale from 1 to 10 (10 being highest) was used. Muscular strength, power, and endurance received the highest rating scores. Panel consensus concluded that (a) selected fitness components (particularly for skill-related fitness components) are currently not being assessed by the military; (b) field-expedient options to measure both health-based and skill-based fitness components are currently available; and (c) 95% of the panel concurred that all services should consider a tier II test focused on both health-related and skill-related fitness components based on occupational, functional, and tactical military performance requirements.

Interface control of the magnetic chirality in CoFeB/MgO heterostructures with heavy-metal underlayers.

PubMed

Torrejon, Jacob; Kim, Junyeon; Sinha, Jaivardhan; Mitani, Seiji; Hayashi, Masamitsu; Yamanouchi, Michihiko; Ohno, Hideo

2014-08-18

Recent advances in the understanding of spin orbital effects in ultrathin magnetic heterostructures have opened new paradigms to control magnetic moments electrically. The Dzyaloshinskii-Moriya interaction (DMI) is said to play a key role in forming a Néel-type domain wall that can be driven by the spin Hall torque. Here we show that the strength and sign of the DMI can be changed by modifying the adjacent heavy-metal underlayer (X) in perpendicularly magnetized X/CoFeB/MgO heterostructures. The sense of rotation of a domain wall spiral is reversed when the underlayer is changed from Hf, Ta to W and the strength of DMI varies as the filling of 5d orbitals, or the electronegativity, of the heavy-metal layer changes. The DMI can even be tuned by adding nitrogen to the underlayer, thus allowing interface engineering of the magnetic texture in ultrathin magnetic heterostructures.

The Exercising Together Project: Design and recruitment for a randomized, controlled trial to determine the benefits of partnered strength training for couples coping with prostate cancer

PubMed Central

Winters-Stone, Kerri M.; Lyons, Karen S.; Nail, Lillian M.; Beer, Tomasz M.

2011-01-01

Prostate cancer can threaten quality of life for the patient and his spouse and the quality of his marital relationship. The purpose of our study is to evaluate the effects of “Exercising Together” – a partnered strength training program for married couples coping with prostate cancer – on the physical and emotional health of prostate cancer survivors (PCS) and their spouses and on marital quality. We are conducting a 6-month randomized controlled trial with two groups: 1) Exercising Together - a progressive, supervised strength training program and 2) a usual care control condition. The primary aims of this exploratory study are to: 1) Determine the effect of partnered strength training on physical and emotional health (muscle strength, physical function, body composition and self-report physical and mental health) in PCS, 2) Determine the effect of partnered strength training on physical and emotional health in spouses and 3) Explore the effect of partnered strength training on marital quality (incongruence, communication, relationship quality, intimacy) of the PCS and spouse. Target accrual has been met in this study with 64 couples enrolled and randomized to exercise (n=32) or usual care (n=32) groups. This study is the first to examine the feasibility of this exercise format in both the chronically ill patient and spouse and explore benefits at the individual and couple level. PMID:22101224

The Exercising Together project: design and recruitment for a randomized, controlled trial to determine the benefits of partnered strength training for couples coping with prostate cancer.

PubMed

Winters-Stone, Kerri M; Lyons, Karen S; Nail, Lillian M; Beer, Tomasz M

2012-03-01

Prostate cancer can threaten quality of life for the patient and his spouse and the quality of his marital relationship. The purpose of our study is to evaluate the effects of "Exercising Together" - a partnered strength training program for married couples coping with prostate cancer - on the physical and emotional health of prostate cancer survivors (PCS) and their spouses and on marital quality. We are conducting a 6-month randomized controlled trial with two groups: 1) Exercising Together - a progressive, supervised strength training program and 2) a usual care control condition. The primary aims of this exploratory study are to: 1) Determine the effect of partnered strength training on physical and emotional health (muscle strength, physical function, body composition and self-report physical and mental health) in PCS, 2) Determine the effect of partnered strength training on physical and emotional health in spouses and 3) Explore the effect of partnered strength training on marital quality (incongruence, communication, relationship quality, intimacy) of the PCS and spouse. Target accrual has been met in this study with 64 couples enrolled and randomized to exercise (n=32) or usual care (n=32) groups. This study is the first to examine the feasibility of this exercise format in both the chronically ill patient and spouse and explore benefits at the individual and couple level. Copyright © 2011 Elsevier Inc. All rights reserved.

Low- and High-Volume Water-Based Resistance Training Induces Similar Strength and Functional Capacity Improvements in Older Women: A Randomized Study.

PubMed

Reichert, Thaís; Delevatti, Rodrigo Sudatti; Prado, Alexandre Konig Garcia; Bagatini, Natália Carvalho; Simmer, Nicole Monticelli; Meinerz, Andressa Pellegrini; Barroso, Bruna Machado; Costa, Rochelle Rocha; Kanitz, Ana Carolina; Kruel, Luiz Fernando Martins

2018-03-27

Water-based resistance training (WRT) has been indicated to promote strength gains in elderly population. However, no study has compared different training strategies to identify the most efficient one. The aim of this study was to compare the effects of 3 WRT strategies on the strength and functional capacity of older women. In total, 36 women were randomly allocated to training groups: simple set of 30 seconds [1 × 30s; 66.41 (1.36) y; n = 12], multiple sets of 10 seconds [3 × 10s; 66.50 (1.43) y; n = 11], and simple set of 10 seconds [1 × 10s; 65.23 (1.09) y; n = 13]. Training lasted for 12 weeks. The maximal dynamic strength (in kilograms) and muscular endurance (number of repetitions) of knee extension, knee flexion, elbow flexion, and bench press, as well as functional capacity (number of repetitions), were evaluated. All types of training promoted similar gains in maximal dynamic strength of knee extension and flexion as well as elbow flexion. Only the 1 × 30s and 1 × 10s groups presented increments in bench press maximal strength. All 3 groups showed increases in muscular endurance in all exercises and functional capacity. WRT using long- or short-duration simple sets promotes the same gains in strength and functional capacity in older women as does WRT using multiple sets.

EFFECTS OF WHOLE BODY VIBRATION ON STRENGTH AND JUMPING PERFORMANCE IN VOLLEYBALL AND BEACH VOLLEYBALL PLAYERS

PubMed Central

Zmijewski, P.; Jimenez-Olmedo, J.M.; Jové-Tossi, M.A.; Martínez-Carbonell, A.; Suárez-Llorca, C.; Andreu-Cabrera, E.

2014-01-01

The primary aim of this study was to examine the effects of 6-week strength training with whole body vibration (WBV) on leg strength and jumping performance in volleyball and beach volleyball players. Twenty-three sub-elite male volleyball (VB; n=12) and beach volleyball players (BVB; n=11) aged 21.2±3.0 years were divided into two groups and subjected to 6 weeks of strength training (three one-hour sessions per week): (I) 12 players (6 VB and 6 BVB players) underwent training with WBV (30-40 Hz, 1.7-2.5 mm, 3.0-5.7 g), and (II) 11 players (6 VB and 5 BVB players) underwent traditional strength training. Squat jump (SJ) and countermovement squat jump (CMJ) measurements by the Ergo Tester contact platform and maximum leg press test (1RM) were conducted. Three-factor (2 time x 2 WBV use x 2 discipline) analysis of variance for SJ, CMJ and 1RM revealed a significant time main effect (p<0.001), a WBV use effect (p<0.001) and a discipline effect (p<0.001). Significantly greater improvements in the SJ (p<0.001) and CMJ (p<0.001) and in 1RM (p<0.001) were found in the WBV training groups than in traditional training groups. Significant 3-way interaction effects (training, WBV use, discipline kind) were also found for SJ, CMJ and 1RM (p=0.001, p<0.001, p=0.001, respectively). It can be concluded that implementation of 6-week WBV training in routine practice in volleyball and beach volleyball players increases leg strength more and leads to greater improvement in jump performance than traditional strength training, but greater improvements can be expected in beach volleyball players than in volleyball players. PMID:25187676

Effects of an integrated health education and elastic band resistance training program on physical function and muscle strength in community-dwelling elderly women: Healthy Aging and Happy Aging II study.

PubMed

Oh, Seung-Lyul; Kim, Hee-Jae; Woo, Shinae; Cho, Be-Long; Song, Misoon; Park, Yeon-Hwan; Lim, Jae-Young; Song, Wook

2017-05-01

In the present study, we determined the effect of an integrated health education and elastic band resistance training program on body composition, physical function, muscle strength and quality in community-dwelling elderly women. We recruited participants with eligibility inclusion criteria, and randomly assigned them to either the control group (n = 19) or the intervention group (n = 19). The integrated intervention program comprised of health education and individual counseling, and elastic band training for 18 weeks (8 weeks of supervised training and 10 weeks of self-directed training). We assessed body composition, muscle strength and quality, and physical function at pre-, after 8 weeks (mid-) and 18 weeks (post-training). After the intervention, there were no significant changes in skeletal muscle index, fat free mass, total lean mass and total fat mass for both the control group and intervention group. However, the interaction effect was significantly different in SPPB score (P < 0.05), isokinetic strength (60 deg/s, P < 0.001; 120 deg/s; P < 0.05) and muscle quality (P < 0.05) after 18 weeks of intervention relative to the baseline of the control and intervention groups. The supervised elastic band training of 8 weeks did not improve short physical performance battery score and isokinetic strength, whereas there was a significant increase of those outcomes (10.6% improvement, 9.8~23.5% improvement) after 10 weeks of following self-directed exercise compared with the baseline. These results show the effectiveness of following self-directed resistance training with health education after supervised training cessation in improvement of short physical performance battery and leg muscle strength. This intervention program might be an effective method to promote muscle strength and quality, and to prevent frailty in elderly women. Geriatr Gerontol Int 2017; 17: 825-833. © 2016 Japan Geriatrics Society.

Effect of core strength and endurance training on performance in college students: randomized pilot study.

PubMed

Schilling, Jim F; Murphy, Jeff C; Bonney, John R; Thich, Jacob L

2013-07-01

Core training continues to be emphasized with the proposed intent of improving athletic performance. The purpose of this investigation was to discover if core isometric endurance exercises were superior to core isotonic strengthening exercises and if either influenced specific endurance, strength, and performance measures. Ten untrained students were randomly assigned to core isometric endurance (n = 5) and core isotonic strength training (n = 5). Each performed three exercises, two times per week for six weeks. A repeated measures ANOVA was used to compare the measurements for the dependent variables and significance by bonferroni post-hoc testing. The training protocols were compared using a 2 × 3 mixed model ANOVA. Improvement in trunk flexor and extensor endurance (p < 0.05) along with squat and bench press strength (p < 0.05) occurred with the strength group. Improvement in trunk flexor and right lateral endurance (p < 0.05) along with strength in the squat (p < 0.05) were found with the endurance group. Neither training protocol claimed superiority and both were ineffective in improving performance. Published by Elsevier Ltd.

Strength Training: Program Organization and Proper Neck Development.

ERIC Educational Resources Information Center

Riley, Dan

During the 1960s, weightlifters and bodybuilders were the primary source for strength training methods, and their techniques were used by coaches to train athletes. In weight-training, it is the responsibility of trainers and coaches to provide the athlete with a program that produces the best results, consumes the least amount of time, and best…

Effects of Electrical Stimulation, Exercise Training and Motor Skills Training on Strength of Children with Meningomyelocele: A Systematic Review

ERIC Educational Resources Information Center

Dagenais, Liese M.; Lahay, Erin R.; Stueck, Kailey A.; White, Erin; Williams, Lindsay; Harris, Susan R.

2009-01-01

This systematic review provides a critical synthesis of research regarding the effects of electrical stimulation, exercise training, and motor skills training on muscle strength in children with meningomyelocele. Nine databases were searched using terms related to meningomyelocele and physical therapy interventions. Of 298 potentially relevant…

Optimizing performance by improving core stability and core strength.

PubMed

Hibbs, Angela E; Thompson, Kevin G; French, Duncan; Wrigley, Allan; Spears, Iain

2008-01-01

Core stability and core strength have been subject to research since the early 1980s. Research has highlighted benefits of training these processes for people with back pain and for carrying out everyday activities. However, less research has been performed on the benefits of core training for elite athletes and how this training should be carried out to optimize sporting performance. Many elite athletes undertake core stability and core strength training as part of their training programme, despite contradictory findings and conclusions as to their efficacy. This is mainly due to the lack of a gold standard method for measuring core stability and strength when performing everyday tasks and sporting movements. A further confounding factor is that because of the differing demands on the core musculature during everyday activities (low load, slow movements) and sporting activities (high load, resisted, dynamic movements), research performed in the rehabilitation sector cannot be applied to the sporting environment and, subsequently, data regarding core training programmes and their effectiveness on sporting performance are lacking. There are many articles in the literature that promote core training programmes and exercises for performance enhancement without providing a strong scientific rationale of their effectiveness, especially in the sporting sector. In the rehabilitation sector, improvements in lower back injuries have been reported by improving core stability. Few studies have observed any performance enhancement in sporting activities despite observing improvements in core stability and core strength following a core training programme. A clearer understanding of the roles that specific muscles have during core stability and core strength exercises would enable more functional training programmes to be implemented, which may result in a more effective transfer of these skills to actual sporting activities.

Effects of resistance training, endurance training and whole-body vibration on lean body mass, muscle strength and physical performance in older people: a systematic review and network meta-analysis.

PubMed

Lai, Chih-Chin; Tu, Yu-Kang; Wang, Tyng-Guey; Huang, Yi-Ting; Chien, Kuo-Liong

2018-05-01

A variety of different types of exercise are promoted to improve muscle strength and physical performance in older people. We aimed to determine the relative effects of resistance training, endurance training and whole-body vibration on lean body mass, muscle strength and physical performance in older people. A systematic review and network meta-analysis. Adults aged 60 and over. Evidence from randomised controlled trials of resistance training, endurance training and whole-body vibration were combined. The effects of exercise interventions on lean body mass, muscle strength and physical performance were evaluated by conducting a network meta-analysis to compare multiple interventions and usual care. Risk of bias of included studies was assessed using the Cochrane Collaboration's tool. A meta-regression was performed to assess potential effect modifiers. Data were obtained from 30 trials involving 1,405 participants (age range: 60-92 years). No significant differences were found between the effects of exercise or usual care on lean body mass. Resistance training (minimum 6 weeks duration) achieved greater muscle strength improvement than did usual care (12.8 kg; 95% confidence interval [CI]: 8.5-17.0 kg). Resistance training and whole-body vibration were associated with greater physical performance improvement compared with usual care (2.6 times greater [95% CI: 1.3-3.9] and 2.1 times greater [95% CI: 0.5-3.7], respectively). Resistance training is the most effect intervention to improve muscle strength and physical performance in older people. Our findings also suggest that whole-body vibration is beneficial for physical performance. However, none of the three exercise interventions examined had a significant effect on lean body mass.

Effects of different exercise interventions on risk of falls, gait ability, and balance in physically frail older adults: a systematic review.

PubMed

Cadore, Eduardo Lusa; Rodríguez-Mañas, Leocadio; Sinclair, Alan; Izquierdo, Mikel

2013-04-01

The aim of this review was to recommend training strategies that improve the functional capacity in physically frail older adults based on scientific literature, focusing specially in supervised exercise programs that improved muscle strength, fall risk, balance, and gait ability. Scielo, Science Citation Index, MEDLINE, Scopus, Sport Discus, and ScienceDirect databases were searched from 1990 to 2012. Studies must have mentioned the effects of exercise training on at least one of the following four parameters: Incidence of falls, gait, balance, and lower-body strength. Twenty studies that investigated the effects of multi-component exercise training (10), resistance training (6), endurance training (1), and balance training (3) were included in the present revision. Ten trials investigated the effects of exercise on the incidence of falls in elderly with physical frailty. Seven of them have found a fewer falls incidence after physical training when compared with the control group. Eleven trials investigated the effects of exercise intervention on the gait ability. Six of them showed enhancements in the gait ability. Ten trials investigated the effects of exercise intervention on the balance performance and seven of them demonstrated enhanced balance. Thirteen trials investigated the effects of exercise intervention on the muscle strength and nine of them showed increases in the muscle strength. The multi-component exercise intervention composed by strength, endurance and balance training seems to be the best strategy to improve rate of falls, gait ability, balance, and strength performance in physically frail older adults.

Effects of Different Exercise Interventions on Risk of Falls, Gait Ability, and Balance in Physically Frail Older Adults: A Systematic Review

PubMed Central

Cadore, Eduardo Lusa; Rodríguez-Mañas, Leocadio; Sinclair, Alan

2013-01-01

Abstract The aim of this review was to recommend training strategies that improve the functional capacity in physically frail older adults based on scientific literature, focusing specially in supervised exercise programs that improved muscle strength, fall risk, balance, and gait ability. Scielo, Science Citation Index, MEDLINE, Scopus, Sport Discus, and ScienceDirect databases were searched from 1990 to 2012. Studies must have mentioned the effects of exercise training on at least one of the following four parameters: Incidence of falls, gait, balance, and lower-body strength. Twenty studies that investigated the effects of multi-component exercise training (10), resistance training (6), endurance training (1), and balance training (3) were included in the present revision. Ten trials investigated the effects of exercise on the incidence of falls in elderly with physical frailty. Seven of them have found a fewer falls incidence after physical training when compared with the control group. Eleven trials investigated the effects of exercise intervention on the gait ability. Six of them showed enhancements in the gait ability. Ten trials investigated the effects of exercise intervention on the balance performance and seven of them demonstrated enhanced balance. Thirteen trials investigated the effects of exercise intervention on the muscle strength and nine of them showed increases in the muscle strength. The multi-component exercise intervention composed by strength, endurance and balance training seems to be the best strategy to improve rate of falls, gait ability, balance, and strength performance in physically frail older adults. PMID:23327448

Strength and endurance training of an individual with left upper and lower limb amputations.

PubMed

Donachy, J E; Brannon, K D; Hughes, L S; Seahorn, J; Crutcher, T T; Christian, E L

2004-04-22

The purpose of this article is to describe the development of a strength and endurance training programme designed to prepare an individual with a left glenohumeral disarticulation and transtibial amputation for a bike trip across the USA. The subject was scheduled for training three times per week over a two-month period followed by two times per week for an additional two months. Training consisted of a resistance training circuit using variable resistance machines, cycling using a recumbent stationary bike, and core stability training using stability ball exercises. Changes in strength were assessed using 10 RM tests on the resistance machines and changes in peak VO(2) were monitored utilizing the Cosmed K4b pulmonary function tester. The subject demonstrated a 30.3% gain in peak VO(2). The subject's 10 RM for left single limb leg press increased 36.8% and gains of at least 7.7% were seen for all other muscle groups tested. The strength and endurance training programme adapted to compensate for this subject's limb losses was effective in increasing both strength and peak VO(2). Adapting exercise programmes to compensate for limb loss may allow individuals with amputations to participate in physically challenging activities that otherwise may not be available to them.

Functional polymorphisms associated with human muscle size and strength.

PubMed

Thompson, Paul D; Moyna, Niall; Seip, Richard; Price, Thomas; Clarkson, Priscilla; Angelopoulos, Theodore; Gordon, Paul; Pescatello, Linda; Visich, Paul; Zoeller, Robert; Devaney, Joseph M; Gordish, Heather; Bilbie, Stephen; Hoffman, Eric P

2004-07-01

Skeletal muscle is critically important to human performance and health, but little is known of the genetic factors influencing muscle size, strength, and its response to exercise training. The Functional single nucleotide polymorphisms (SNP) Associated with Muscle Size and Strength, or FAMuSS, Study is a multicenter, NIH-funded program to examine the influence of gene polymorphisms on skeletal muscle size and strength before and after resistance exercise training. One thousand men and women, age 18 - 40 yr, will train their nondominant arm for 12 wk. Skeletal muscle size (magnetic resonance imaging) and isometric and dynamic strength will be measured before and after training. Individuals whose baseline values or response to training deviate > or = 1.5 SD will be defined as outliers and examined for genetic variants. Initially candidate genes previously associated with muscle performance will be examined, but the study will ultimately attempt to identify genes associated with muscle performance. FAMuSS should help identify genetic factors associated with muscle performance and the response to exercise training. Such insight should contribute to our ability to predict the individual response to exercise training but may also contribute to understanding better muscle physiology, to identifying individuals who are susceptible to muscle loss with environmental challenge, and to developing pharmacologic agents capable of preserving muscle size and function.

High-intensity interval training combined with resistance training improves physiological capacities, strength and quality of life in multiple sclerosis patients: a pilot study.

PubMed

Zaenker, Pierre; Favret, Fabrice; Lonsdorfer, Evelyne; Muff, Guillaume; de Seze, Jérôme; Isner-Horobeti, Marie-Eve

2018-02-01

Numerous studies have shown that mild-to-moderate intensity or resistance exercise training improves physical capacities such as, peak oxygen consumption, maximal tolerated power and strength in multiple sclerosis patients. However, few studies have evaluated the effects of high-intensity interval training (HIIT) associated to with resistance training. Only few studies have analyzed difference between men and women before and after combined training. Moreover, the evaluation of exercise between ambulatory multiple sclerosis patients without disability (Expanded Disability Status Score [EDSS] 0-3) and patients with disabilities (EDSS 3.5-5) was not largely published. The main objective of our study was to determine if HIIT combined with resistance training improved aerobic and strength capacities as well as quality of life in multiple sclerosis patients and if gender and disabilities play a role in these changes. This study was an open-label uncontrolled study. The study was performed outside from conventional care facilities and including homebased training. Twenty-six multiple sclerosis patients have completed the program (19 women, 7 men; mean age 44.6±7.9 years, EDSS 2 [0-5]). We conducted a 12-week program of high-intensity interval training combined with resistance training at body weight. Peak oxygen consumption, maximal tolerated power, lactates, isokinetic strength of quadriceps and hamstrings (at 90°/s, 180°/s, and 240°/s) and quality of life were evaluated before and after the program. Peak oxygen consumption and maximum tolerated power improved by 13.5% and 9.4%, respectively. Isokinetic muscle strength increased in both quadriceps and hamstrings at each speed, with a rebalancing of strength between the two legs in quadriceps. Quality of life was also enhanced in three domains. Women showed better improvements than men in V̇O2peak, maximal tolerated power, lactates at the end of test, and heart rate peak, strength in both quadriceps and hamstrings mostly at low speed, and quality of life. The two EDSS groups increased V̇O2peak and strength. Our study has shown that HIIT combined with resistance exercise training induced an improvement in physical capacity and quality of life. Moreover, this study allowed patients, irrespective of their sex or EDSS score, to resume exercise autonomously. The results of the study showed that aerobic training at moderate intensity is not the single type of training tolerated by multiple sclerosis patients. High-intensity interval training is well tolerated too and can be used in clinical rehabilitation with resistance training, in both men and women with and without disabilities.

Combined isometric and vibration training does not enhance strength beyond that of isometric training alone.

PubMed

Fisher, J; Van-Dongen, M; Sutherland, R

2014-10-08

Research considering combined vibration and strength training is extensive yet results are equivocal. However, to date there appears no research which has considered the combination of both direct vibration and whole---body vibration when used in an isometric deadlift position. The aims of this study were to compare groups performing isometric training with and without direct and whole---body vibration. Twenty four participants (19---24 years) were randomly divided into: isometric training with vibration (ST+VT: n=8), isometric training without vibration (ST: n=8), and control (CON: n=8). Within the training groups participants trained twice per week, for 6 weeks, performing 6---sets of maximal isometric deadlift contractions, increasing in duration from 30 seconds to 40 seconds (weeks 1---6). Hip and knee angle was maintained at 60° and 110°, respectively for both testing and training. Training sessions for ST+VT were identical to ST with the addition of a direct vibratory stimulus through hand---held straps and whole---body vibration via standing on vibration a platform. The amplitude remained constant (2mm) throughout the intervention whilst the frequency increased from 35Hz to 50Hz. Pre--- and post---test isometric strength was measured using an isometric deadlift dynamometer. Results revealed significant increases in isometric strength for both ST+VT (p < 0.001, 23.8%) and ST (p < 0.001, 32.5%) compared to CON, with no significant differences between ST+VT and ST training groups. The present study provides evidence to suggest that there are no greater gains to be incurred by the addition of a vibratory stimulus to traditional strength training.

Combined isometric and vibration training does not enhance strength beyond that of isometric training alone.

PubMed

Fisher, J; Van-Dongen, M; Sutherland, R

2015-09-01

Research considering combined vibration and strength training is extensive yet results are equivocal. However, to date there appears no research which has considered the combination of both direct vibration and whole-body vibration when used in an isometric deadlift position. The aim of this study was to compare groups performing isometric training with and without direct and whole-body vibration. Twenty four participants (19-24 years) were randomly divided into: isometric training with vibration (ST+VT: N.=8), isometric training without vibration (ST: N.=8), and control (CON: N.=8). Within the training groups participants trained twice per week, for 6 weeks, performing 6-sets of maximal isometric deadlift contractions, increasing in duration from 30 seconds to 40 seconds (weeks 1-6). Hip and knee angle was maintained at 60° and 110°, respectively for both testing and training. Training sessions for ST+VT were identical to ST with the addition of a direct vibratory stimulus through hand-held straps and whole-body vibration via standing on vibration a platform. The amplitude remained constant (2 mm) throughout the intervention whilst the frequency increased from 35Hz to 50Hz. Pre- and post-test isometric strength was measured using an isometric deadlift dynamometer. Results revealed significant increases in isometric strength for both ST+VT (P<0.001, 23.8%) and ST (P<0.001, 32.5%) compared to CON, with no significant differences between ST+VT and ST training groups. The present study provides evidence to suggest that there are no greater gains to be incurred by the addition of a vibratory stimulus to traditional strength training.

Effects of Different Modes of Exercise Training on Body Composition and Risk Factors for Cardiovascular Disease in Middle-aged Men

PubMed Central

Mohammadi, Hamid Reza; Khoshnam, Mohammad Sadegh; Khoshnam, Ebrahim

2018-01-01

Background: Previous studies have indicated that exercise training improves body composition and cardiovascular disease risk factors. The aim of the present study was to investigate the effect of 12 weeks of aerobic, strength and combined training on body composition, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and C-reactive protein (CRP) in sedentary middle-aged men. Methods: Forty-seven male aged 40–60 years voluntarily participated in this study and were divided in four groups: aerobic (n = 12), strength (n = 12), combined (n = 11), and control (n = 12) groups randomly. Body composition, ICAM-1, VCAM-1, and CRP were measured before and after 12 weeks. Data were analyzed using paired t-test and analysis of variance statistical methods. Results: There were significant differences in body weight between aerobic and strength training (P = 0.004) and aerobic and control groups (P = 0.018), body mass index between combined and strength training (P = 0.004) and combined and control groups (P = 0.001), fat percentage between aerobic training and control group (P = 0.017) and combined training and control groups (P = 0.004), and finally, fat-free mass between aerobic and strength training (P = 0.024), aerobic and combined training (P = 0.0001), strength and control groups (P = 0.035), and combined and control groups (P = 0.0001). Conclusions: The results indicated that 12-week workout, 20–60 min/session, 3 days a week of moderate intensity exercise improved body composition, ICAM-1, VCAM-1, and CRP compared to those who did not participate in any training. However, all three types of exercises had small benefits on body composition, ICAM-1, VCAM-1, and CRP in sedentary middle-aged men, and the importance of combined training required further investigations. PMID:29441186

Effect of strength training on regional hypertrophy of the elbow flexor muscles.

PubMed

Drummond, Marcos D M; Szmuchrowski, Leszek A; Goulart, Karine N O; Couto, Bruno P

2016-10-01

Muscle hypertrophy is the main structural adaptation to strength training. We investigated the chronic effects of strength training on muscle hypertrophy in different regions of the elbow flexor muscles. Eleven untrained men (21.8 ± 1.62 years) underwent magnetic resonance imaging to determine the proximal, medial, distal, and mean cross-sectional areas (CSA) of the elbow flexors. The volunteers completed 12 weeks of strength training. The training protocol consisted of 4 sets of 8-10 maximum repetitions of unilateral elbow flexion. The interval between sets was 120 s. The training frequency was 3 sessions per week. The magnetic resonance images verified the presence of significant and similar hypertrophy in the distal, medial, and proximal portions of the elbow flexor muscles. Muscle hypertrophy may be assessed using only the medial CSA. We should not expect different degrees of hypertrophy among the regions of the elbow flexor muscles. Muscle Nerve 54: 750-755, 2016. © 2016 Wiley Periodicals, Inc.

Preventive strength training improves working ergonomics during welding.

PubMed

Krüger, Karsten; Petermann, Carmen; Pilat, Christian; Schubert, Emil; Pons-Kühnemann, Jörn; Mooren, Frank C

2015-01-01

To investigate the effect of a preventive strength training program on cardiovascular, metabolic and muscular strains during welding. Welders are one of the occupation groups which typically have to work in extended forced postures which are known to be an important reason for musculoskeletal disorders. Subjects (exercise group) accomplished a 12-week strength training program, while another group served as controls (control group). Pre and post training examinations included the measurements of the one repetition maximum and an experimental welding test. Local muscle activities were analysed by surface electromyography. Furthermore, heart rate, blood pressure, lactate and rating of perceived exertion were examined. In the exercise group, strength training lead to a significant increase of one repetition maximum in all examined muscles (p<.05). During the experimental welding test muscle activities of trunk and shoulder muscles and arm muscles were significantly reduced in the exercise group after intervention (p<.05). While no changes of neither cardiovascular nor metabolic parameters were found, subjects of the exercise group rated a significantly decreased rate of perceived exertion welding (p<.05). Effects of strength training can be translated in an improved working ergonomics and tolerance against the exposure to high physical demands at work.

Acute Effects of Static vs. Ballistic Stretching on Strength and Muscular Fatigue Between Ballet Dancers and Resistance-Trained Women.

PubMed

Lima, Camila D; Brown, Lee E; Wong, Megan A; Leyva, Whitney D; Pinto, Ronei S; Cadore, Eduardo L; Ruas, Cassio V

2016-11-01

Lima, CD, Brown, LE, Wong, MA, Leyva, WD, Pinto, RS, Cadore, EL, and Ruas, CV. Acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. J Strength Cond Res 30(11): 3220-3227, 2016-Stretching is used to increase joint range of motion, but the acute effects can decrease muscle strength. However, this may depend on the population or mode of stretching. The purpose of this study was to compare the acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. Fifteen resistance-trained women (age 23.8 ± 1.80 years, mass 67.47 ± 7.77 kg, height 168.30 ± 5.53 cm) and 12 ballet dancers (age 22.8 ± 3.04 years, mass 58.67 ± 5.65 kg, height 168.00 ± 7.69 cm) performed 5 days of testing. The first day was control (no stretching), whereas the other 4 days were static or ballistic stretching in a counterbalanced order. Range of motion, strength, and fatigue tests were also performed. Both groups demonstrated a significant decrease in hamstrings strength after static (102.71 ± 2.67 N·m) and ballistic stretching (99.49 ± 2.61 N·m) compared with control (113.059 ± 3.25 N·m), with no changes in quadriceps strength. For fatigue, only ballet dancers demonstrated a decrease from control (71.79 ± 4.88%) to ballistic (65.65 ± 8.19%), but no difference with static (65.01 ± 12.29%). These findings suggest that stretching decreases hamstrings strength similarly in ballet dancers and resistance-trained women, with no differences between modes of stretching. However, ballistic stretching only decreased muscular fatigue in ballet dancers, but not in resistance-trained women. Therefore, no stretching should be performed before strength performance. However, ballistic stretching may decrease acute muscular fatigue in ballet dancers.

Undulatory physical resistance training program increases maximal strength in elderly type 2 diabetics.

PubMed

Santos, Gilberto Monteiro dos; Montrezol, Fábio Tanil; Pauli, Luciana Santos Souza; Sartori-Cintra, Angélica Rossi; Colantonio, Emilson; Gomes, Ricardo José; Marinho, Rodolfo; Moura, Leandro Pereira de; Pauli, José Rodrigo

2014-01-01

To investigate the effects of a specific protocol of undulatory physical resistance training on maximal strength gains in elderly type 2 diabetics. The study included 48 subjects, aged between 60 and 85 years, of both genders. They were divided into two groups: Untrained Diabetic Elderly (n=19) with those who were not subjected to physical training and Trained Diabetic Elderly (n=29), with those who were subjected to undulatory physical resistance training. The participants were evaluated with several types of resistance training's equipment before and after training protocol, by test of one maximal repetition. The subjects were trained on undulatory resistance three times per week for a period of 16 weeks. The overload used in undulatory resistance training was equivalent to 50% of one maximal repetition and 70% of one maximal repetition, alternating weekly. Statistical analysis revealed significant differences (p<0.05) between pre-test and post-test over a period of 16 weeks. The average gains in strength were 43.20% (knee extension), 65.00% (knee flexion), 27.80% (supine sitting machine), 31.00% (rowing sitting), 43.90% (biceps pulley), and 21.10% (triceps pulley). Undulatory resistance training used with weekly different overloads was effective to provide significant gains in maximum strength in elderly type 2 diabetic individuals.

Short-term low-intensity blood flow restricted interval training improves both aerobic fitness and muscle strength.

PubMed

de Oliveira, M F M; Caputo, F; Corvino, R B; Denadai, B S

2016-09-01

The present study aimed to analyze and compare the effects of four different interval-training protocols on aerobic fitness and muscle strength. Thirty-seven subjects (23.8 ± 4 years; 171.7 ± 9.5 cm; 70 ± 11 kg) were assigned to one of four groups: low-intensity interval training with (BFR, n = 10) or without (LOW, n = 7) blood flow restriction, high-intensity interval training (HIT, n = 10), and combined HIT and BFR (BFR + HIT, n = 10, every session performed 50% as BFR and 50% as HIT). Before and after 4 weeks training (3 days a week), the maximal oxygen uptake (VO2max ), maximal power output (Pmax ), onset blood lactate accumulation (OBLA), and muscle strength were measured for all subjects. All training groups were able to improve OBLA (BFR, 16%; HIT, 25%; HIT + BFR, 22%; LOW, 6%), with no difference between groups. However, VO2max and Pmax improved only for BFR (6%, 12%), HIT (9%, 15%) and HIT + BFR (6%, 11%), with no difference between groups. Muscle strength gains were only observed after BFR training (11%). This study demonstrates the advantage of short-term low-intensity interval BFR training as the single mode of training able to simultaneously improve aerobic fitness and muscular strength. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Exercise-Based Fall Prevention in the Elderly: What About Agility?

PubMed

Donath, Lars; van Dieën, Jaap; Faude, Oliver

2016-02-01

Annually, one in three seniors aged over 65 years fall. Balance and strength training can reduce neuromuscular fall risk factors and fall rates. Besides conventional balance and strength training, explosive or high-velocity strength training, eccentric exercises, perturbation-based balance training, trunk strength, and trunk control have also been emphasized. In contrast, aerobic exercise has to date not been included in fall-prevention studies. However, well-developed endurance capacity might attenuate fatigue-induced declines in postural control in sports-related or general activities of daily living. Physical performance indices, such as balance, strength, and endurance, are generally addressed independently in exercise guidelines. This approach seems time consuming and may impede integrative training of sensorimotor, neuromuscular, and cardiocirculatory functions required to deal with balance-threatening situations in the elderly. An agility-based conceptual training framework comprising perception and decision making (e.g., visual scanning, pattern recognition, anticipation) and changes of direction (e.g., sudden starts, stops and turns; reactive control; concentric and eccentric contractions) might enable an integrative neuromuscular, cardiocirculatory, and cognitive training. The present paper aims to provide a scientific sketch of how to build such an integrated modular training approach, allowing adaptation of intensity, complexity, and cognitive challenge of the agility tasks to the participant's capacity. Subsequent research should address the (1) link between agility and fall risk factors as well as fall rates, (2) benefit-risk ratios of the proposed approach, (3) psychosocial aspects of agility training (e.g., motivation), and (4) logistical requirements (e.g., equipment needed).

Effect of a 10-week strength training program and recovery drink on body composition, muscular strength and endurance, and anaerobic power and capacity.

PubMed

Chromiak, Joseph A; Smedley, Brianne; Carpenter, William; Brown, Robert; Koh, Yun S; Lamberth, John G; Joe, Lee Ann; Abadie, Ben R; Altorfer, Greg

2004-05-01

We investigated whether postexercise consumption of a supplement containing whey protein, amino acids, creatine, and carbohydrate combined with a strength training program promotes greater gains in fat-free mass (FFM), muscle strength and endurance, and anaerobic performance compared with an isocaloric, carbohydrate-only control drink combined with strength training. The study was double blind and randomized, and the experimental supplement was compared with a carbohydrate-only control. Forty-one males (n = 20 in control group, n = 21 in the supplement group; mean age, 22.2 y) participated in a 4 d/wk, 10-wk periodized strength training program. Subjects had to complete at least 70% of the workouts. Before and after 10 wk of strength training, subjects were tested for body composition by using hydrostatic weighing and skinfold thicknesses, one repetition maximum strength and muscular endurance for the bench press and 45-degree leg press, and anaerobic performance using a 30-s Wingate test. Thirty-three subjects (80.5%) completed the training program (n = 15 in control group, n = 18 in the supplement); these 33 subjects also completed all post-training test procedures. Data were analyzed with two-way analysis of variance with repeated measures on time. P <== 0.05 was set as statistically significant. All statistical analyses, including calculation of effect size and power, were completed with SPSS 11.0. Across groups, FFM increased during 10 wk of strength training. Although there was no statistically significant time x group interaction for FFM, there was a trend toward a greater increase in FFM for the supplement group (+3.4 kg) compared with the control group (+1.5 kg; P = 0.077). The effect size (eta(2) = 0.100) was moderately large. Percentage of body fat declined and fat mass was unchanged; there were no differences between groups. One repetition maximum strength for the bench press and 45-degree leg press increased, but there were no differences between groups. Muscular endurance expressed as the number of repetitions completed with 85% of the one repetition maximum was unchanged; external work, which was estimated as repetitions completed x resistance used, increased for the 45-degree leg press but not for the bench press over the 10-wk training period; there were no time x group interactions for either measurement. Anaerobic power and capacity improved, but there were no differences between groups for these variables or for fatigue rate. Consumption of a recovery drink after strength training workouts did not promote greater gains in FFM compared with consumption of a carbohydrate-only drink; however, a trend toward a greater increase in FFM in the supplement group suggests the need for longer-term studies. Performance variables such as muscle strength and endurance and anaerobic performance were not improved when compared with the carbohydrate-only group.

Heavy Equipment. Trade and Industrial Education Trade Preparatory Training Guide.

ERIC Educational Resources Information Center

Nebraska State Dept. of Education, Lincoln. Div. of Vocational Education.

One of a series of curriculum guides prepared for the building occupations cluster of the construction/fabrication occupational group, this guide identifies the essentials of the heavy equipment trade as recommended by the successful heavy equipment operator. An instructional program based upon the implementation of the guide is expected to…

Dynamic response of the train-track-bridge system subjected to derailment impacts

NASA Astrophysics Data System (ADS)

Ling, Liang; Dhanasekar, Manicka; Thambiratnam, David P.

2018-04-01

Derailments on bridges, although not frequent, when occurs due to a complex dynamic interaction of the train-track-bridge structural system, are very severe. Furthermore, the forced vibration induced by the post-derailment impacts can toss out the derailed wagons from the bridge deck with severe consequences to the traffic underneath and the safety of the occupants of the wagons. This paper presents a study of the train-track-bridge interaction during a heavy freight train crossing a concrete box girder bridge from a normal operation to a derailed state. A numerical model that considers the bridge vibration, train-track interaction and the train post-derailment behaviour is formulated based on a coupled finite-element - multi-body dynamics (FE-MBD) theory. The model is applied to predict the post-derailment behaviour of a freight train composed of one locomotive and several wagons, as well as the dynamic response of a straight single-span simply supported bridge containing ballast track subjected to derailment impacts. For this purpose, a typical derailment scenario of a heavy freight train passing over a severe track geometry defect is introduced. The dynamic derailment behaviour of the heavy freight train and the dynamic responses of the rail bridge are illustrated through numerical examples. The results exhibit the potential for tossing out of the derailed trains from the unstable increase in the yaw angle signature and a lower rate of increase of the bridge deck bending moment compared to the increase in the static axle load of the derailed wheelset.

Effort, performance, and motivation: insights from robot-assisted training of human golf putting and rat grip strength.

PubMed

Duarte, Jaime E; Gebrekristos, Berkenesh; Perez, Sergi; Rowe, Justin B; Sharp, Kelli; Reinkensmeyer, David J

2013-06-01

Robotic devices can modulate success rates and required effort levels during motor training, but it is unclear how this affects performance gains and motivation. Here we present results from training unimpaired humans in a virtual golf-putting task, and training spinal cord injured (SCI) rats in a grip strength task using robotically modulated success rates and effort levels. Robotic assistance in golf practice increased trainees feelings of competence, and, paradoxically, increased their sense effort, even though it had mixed effects on learning. Reducing effort during a grip strength training task led rats with SCI to practice the task more frequently. However, the more frequent practice of these rats did not cause them to exceed the strength gains achieved by rats that exercised less often at higher required effort levels. These results show that increasing success and decreasing effort with robots increases motivation, but has mixed effects on performance gains.

Side-alternating vibration training for balance and ankle muscle strength in untrained women.

PubMed

Spiliopoulou, Styliani I; Amiridis, Ioannis G; Tsigganos, Georgios; Hatzitaki, Vassilia

2013-01-01

Side-alternating vibration (SAV) may help reduce the risk of falling by improving body balance control. Such training has been promoted as a strength-training intervention because it can increase muscle activation through an augmented excitatory input from the muscle spindles. To determine the effect of SAV training on static balance during 3 postural tasks of increasing difficulty and lower limb strength. Randomized controlled clinical trial. Laboratory. A total of 21 healthy women were divided into training (n = 11; age = 43.35 ± 4.12 years, height = 169 ± 6.60 cm, mass = 68.33 ± 11.90 kg) and control (n = 10; age = 42.31 ± 3.73 years, height = 167 ± 4.32 cm, mass = 66.29 ± 10.74 kg) groups. The training group completed a 9-week program during which participants performed 3 sessions per week of ten 15-second isometric contractions with a 30-second active rest of 3 exercises (half-squat, wide-stance squat, 1-legged half-squat) on an SAV plate (acceleration = 0.91-16.3g). The control group did not participate in any form of exercise over the 9-week period. We evaluated isokinetic and isometric strength of the knee extensors and flexors and ankle plantar flexors, dorsiflexors, and evertors. Static balance was assessed using 3 tasks of increasing difficulty (quiet bipedal stance, tandem stance, 1-legged stance). The electromyographic activity of the vastus lateralis, semitendinosus, medial gastrocnemius, tibialis anterior, and peroneus longus was recorded during postural task performance, baseline and pretraining, immediately posttraining, and 15 days posttraining. After training in the training group, ankle muscle strength improved (P = .03), whereas knee muscle strength remained unaltered (P = .13). Improved ankle-evertor strength was observed at all angular velocities (P = .001). Postural sway decreased in both directions but was greater in the mediolateral (P < .001) than anteroposterior (P = .02) direction. The electromyographic activity of the peroneus longus increased during the sharpened tandem (P = .001) and 1-legged tasks (P = .007). No changes were seen in the control group for any measures. The SAV training could enhance ankle muscle strength and reduce postural sway during static balance performance. The reduction in mediolateral sway could be associated with the greater use of ankle evertors due to their strength improvement.

Strength Development: Using Functional Isometrics in an Isotonic Strength Training Program.

ERIC Educational Resources Information Center

Jackson, Allen; And Others

1985-01-01

A study was made to determine if a combination of functional isometrics and standard isotonic training would be superior to a standard isotonic program in an instructional setting. The results provide support for functional isometrics as an enhancement where achievement of maximum strength is the goal. (Author/MT)

Effects of a concurrent strength and endurance training on running performance and running economy in recreational marathon runners.

PubMed

Ferrauti, Alexander; Bergermann, Matthias; Fernandez-Fernandez, Jaime

2010-10-01

The purpose of this study was to investigate the effects of a concurrent strength and endurance training program on running performance and running economy of middle-aged runners during their marathon preparation. Twenty-two (8 women and 14 men) recreational runners (mean ± SD: age 40.0 ± 11.7 years; body mass index 22.6 ± 2.1 kg·m⁻²) were separated into 2 groups (n = 11; combined endurance running and strength training program [ES]: 9 men, 2 women and endurance running [E]: 7 men, and 4 women). Both completed an 8-week intervention period that consisted of either endurance training (E: 276 ± 108 minute running per week) or a combined endurance and strength training program (ES: 240 ± 121-minute running plus 2 strength training sessions per week [120 minutes]). Strength training was focused on trunk (strength endurance program) and leg muscles (high-intensity program). Before and after the intervention, subjects completed an incremental treadmill run and maximal isometric strength tests. The initial values for VO2peak (ES: 52.0 ± 6.1 vs. E: 51.1 ± 7.5 ml·kg⁻¹·min⁻¹) and anaerobic threshold (ES: 3.5 ± 0.4 vs. E: 3.4 ± 0.5 m·s⁻¹) were identical in both groups. A significant time × intervention effect was found for maximal isometric force of knee extension (ES: from 4.6 ± 1.4 to 6.2 ± 1.0 N·kg⁻¹, p < 0.01), whereas no changes in body mass occurred. No significant differences between the groups and no significant interaction (time × intervention) were found for VO2 (absolute and relative to VO2peak) at defined marathon running velocities (2.4 and 2.8 m·s⁻¹) and submaximal blood lactate thresholds (2.0, 3.0, and 4.0 mmol·L⁻¹). Stride length and stride frequency also remained unchanged. The results suggest no benefits of an 8-week concurrent strength training for running economy and coordination of recreational marathon runners despite a clear improvement in leg strength, maybe because of an insufficient sample size or a short intervention period.

Longer Interset Rest Periods Enhance Muscle Strength and Hypertrophy in Resistance-Trained Men.

PubMed

Schoenfeld, Brad J; Pope, Zachary K; Benik, Franklin M; Hester, Garrett M; Sellers, John; Nooner, Josh L; Schnaiter, Jessica A; Bond-Williams, Katherine E; Carter, Adrian S; Ross, Corbin L; Just, Brandon L; Henselmans, Menno; Krieger, James W

2016-07-01

Schoenfeld, BJ, Pope, ZK, Benik, FM, Hester, GM, Sellers, J, Nooner, JL, Schnaiter, JA, Bond-Williams, KE, Carter, AS, Ross, CL, Just, BL, Henselmans, M, and Krieger, JW. Longer interset rest periods enhance muscle strength and hypertrophy in resistance-trained men. J Strength Cond Res 30(7): 1805-1812, 2016-The purpose of this study was to investigate the effects of short rest intervals normally associated with hypertrophy-type training versus long rest intervals traditionally used in strength-type training on muscular adaptations in a cohort of young, experienced lifters. Twenty-one young resistance-trained men were randomly assigned to either a group that performed a resistance training (RT) program with 1-minute rest intervals (SHORT) or a group that employed 3-minute rest intervals (LONG). All other RT variables were held constant. The study period lasted 8 weeks with subjects performing 3 total body workouts a week comprised 3 sets of 8-12 repetition maximum (RM) of 7 different exercises per session. Testing was performed prestudy and poststudy for muscle strength (1RM bench press and back squat), muscle endurance (50% 1RM bench press to failure), and muscle thickness of the elbow flexors, triceps brachii, and quadriceps femoris by ultrasound imaging. Maximal strength was significantly greater for both 1RM squat and bench press for LONG compared to SHORT. Muscle thickness was significantly greater for LONG compared to SHORT in the anterior thigh, and a trend for greater increases was noted in the triceps brachii (p = 0.06) as well. Both groups saw significant increases in local upper body muscle endurance with no significant differences noted between groups. This study provides evidence that longer rest periods promote greater increases in muscle strength and hypertrophy in young resistance-trained men.

Eight-Week Vibration Training of the Elbow Flexors by Force Modulation: Effects on Dynamic and Isometric Strength.

PubMed

Xu, Lin; Cardinale, Marco; Rabotti, Chiara; Beju, Bogdan; Mischi, Massimo

2016-03-01

Vibration exercise (VE) has been suggested as an effective method to improve strength and power capabilities. However, the underlying mechanisms in response to VE are still unclear. A pulley-like VE system, characterized by sinusoidal force applications has been developed and tested for proof of concept in a previous study. The aim of this study was to evaluate the effects of such force modulation on elbow flexors strength and compare it with conventional methods. Forty subjects were randomly divided into 4 groups of 10: the vibration group (VG), the no-vibration group (NVG), the dumbbell group (DG), and the control group (CG). Biceps curl exercises were used to train the elbow flexors 2 times a week for 8 weeks. Subjects in the VG were trained using a ramp-up baseline with superimposed 30 Hz sinusoidal vibration whereas the subjects in the NVG were trained using the same baseline but without vibration. Subjects in the DG were trained using dumbbells, and the subjects in the CG were not trained. The isometric break force (IBF) and 1 repetition maximum (1RM) of the subject's dominant arm were assessed before and after the 8-week training period. The VG achieved 1RM improvement (22.7%) larger than the NVG (10.8%) and comparable with the DG (22.3%). Differences in IBF gains following the training period among the training groups were found to be not significant. Our results support the inclusion of the proposed VE in strength training programs aimed at improving dynamic strength on the elbow flexors.

Muscle mechanical properties of strength and endurance athletes and changes after one week of intensive training.

PubMed

de Paula Simola, Rauno Álvaro; Raeder, Christian; Wiewelhove, Thimo; Kellmann, Michael; Meyer, Tim; Pfeiffer, Mark; Ferrauti, Alexander

2016-10-01

The study investigates whether tensiomyography (TMG) is sensitive to differentiate between strength and endurance athletes, and to monitor fatigue after either one week of intensive strength (ST) or endurance (END) training. Fourteen strength (24.1±2.0years) and eleven endurance athletes (25.5±4.8years) performed an intensive training period of 6days of ST or END, respectively. ST and END groups completed specific performance tests as well as TMG measurements of maximal radial deformation of the muscle belly (Dm), deformation time between 10% and 90% Dm (Tc), rate of deformation development until 10% Dm (V10) and 90% Dm (V90) before (baseline), after training period (post1), and after 72h of recovery (post2). Specific performance of both groups decreased from baseline to post1 (P<0.05) and returned to baseline values at post2 (P<0.05). The ST group showed higher countermovement jump (P<0.05) and shorter Tc (P<0.05) at baseline. After training, Dm, V10, and V90 were reduced in the ST (P<0.05) while TMG changes were less pronounced in the END. TMG could be a useful tool to differentiate between strength and endurance athletes, and to monitor fatigue and recovery especially in strength training. Copyright © 2016 Elsevier Ltd. All rights reserved.

Strength Training Following Hematopoietic Stem Cell Transplantation

PubMed Central

Hacker, Eileen Danaher; Larson, Janet; Kujath, Amber; Peace, David; Rondelli, Damiano; Gaston, Lisa

2010-01-01

Background Patients receiving high-dose chemotherapy and hematopoietic stem cell transplantation (HSCT) experience considerable reductions in physical activity and deterioration of their health status. Objective The purpose of this pilot study was to test the effects of strength training compared to usual activity on physical activity, muscle strength, fatigue, health status perceptions, and quality of life following HSCT. Interventions/Methods Nineteen subjects were randomized to the exercise or control group. Moderate intensity strength training began following discharge from the hospital. Dependent variables included physical activity, muscle strength, fatigue, health status perceptions and quality of life. Variables were measured prior to admission to the hospital for HSCT, day 8 following HSCT, and six weeks following discharge from the hospital. Results Significant time effects were noted for many variables with anticipated declines in physical activity, muscle strength, fatigue, and health status perceptions immediately after HSCT with subsequent improvements six weeks following hospital discharge. One group effect was noted with subjects in the exercise group reporting less fatigue than subjects in the control group. Although no significant interactions were detected, the trends suggest that the exercise group may be more physically active following the intervention compared to the usual activity group. Conclusions This study demonstrates the potential positive effects of strength training on physical activity, fatigue, and quality of life in people receiving high-dose chemotherapy and HSCT. Implications for Practice Preliminary evidence is provided for using strength training to enhance early recovery following HSCT. Elastic resistance bands are easy to use and relatively inexpensive. PMID:21116175

Greater Strength Gains after Training with Accentuated Eccentric than Traditional Isoinertial Loads in Already Strength-Trained Men

PubMed Central

Walker, Simon; Blazevich, Anthony J.; Haff, G. Gregory; Tufano, James J.; Newton, Robert U.; Häkkinen, Keijo

2016-01-01

As training experience increases it becomes more challenging to induce further neuromuscular adaptation. Consequently, strength trainers seek alternative training methods in order to further increase strength and muscle mass. One method is to utilize accentuated eccentric loading, which applies a greater external load during the eccentric phase of the lift as compared to the concentric phase. Based upon this practice, the purpose of this study was to determine the effects of 10 weeks of accentuated eccentric loading vs. traditional isoinertial resistance training in strength-trained men. Young (22 ± 3 years, 177 ± 6 cm, 76 ± 10 kg, n = 28) strength-trained men (2.6 ± 2.2 years experience) were allocated to concentric-eccentric resistance training in the form of accentuated eccentric load (eccentric load = concentric load + 40%) or traditional resistance training, while the control group continued their normal unsupervised training program. Both intervention groups performed three sets of 6-RM (session 1) and three sets of 10-RM (session 2) bilateral leg press and unilateral knee extension exercises per week. Maximum force production was measured by unilateral isometric (110° knee angle) and isokinetic (concentric and eccentric 30°.s−1) knee extension tests, and work capacity was measured by a knee extension repetition-to-failure test. Muscle mass was assessed using panoramic ultrasonography and dual-energy x-ray absorptiometry. Surface electromyogram amplitude normalized to maximum M-wave and the twitch interpolation technique were used to examine maximal muscle activation. After training, maximum isometric torque increased significantly more in the accentuated eccentric load group than control (18 ± 10 vs. 1 ± 5%, p < 0.01), which was accompanied by an increase in voluntary activation (3.5 ± 5%, p < 0.05). Isokinetic eccentric torque increased significantly after accentuated eccentric load training only (10 ± 9%, p < 0.05), whereas concentric torque increased equally in both the accentuated eccentric load (10 ± 9%, p < 0.01) and traditional (9 ± 6%, p < 0.01) resistance training groups; however, the increase in the accentuated eccentric load group was significantly greater (p < 0.05) than control (1 ± 7%). Knee extension repetition-to-failure improved in the accentuated eccentric load group only (28%, p < 0.05). Similar increases in muscle mass occurred in both intervention groups. In summary, accentuated eccentric load training led to greater increases in maximum force production, work capacity and muscle activation, but not muscle hypertrophy, in strength-trained individuals. PMID:27199764

Does Resistance Training Stimulate Cardiac Muscle Hypertrophy?

ERIC Educational Resources Information Center

Bloomer, Richard J.

2003-01-01

Reviews the literature on the left ventricular structural adaptations induced by resistance/strength exercise, focusing on human work, particularly well-trained strength athletes engaged in regular, moderate- to high-intensity resistance training (RT). The article discusses both genders and examines the use of anabolic-androgenic steroids in…

Weight Training for Strength and Power.

ERIC Educational Resources Information Center

President's Council on Physical Fitness and Sports, Washington, DC.

This paper begins by defining the terms "weight training,""weight lifting,""strength,""power," and "muscular endurance.""Weight training" is differentiated from "weight lifting" and defined as a systematic series of resistance exercises designed to promote physical development and conditioning or to rehabilitate persons who have suffered injury or…

High-intensity aerobic interval training can lead to improvement in skeletal muscle power among in-hospital patients with advanced heart failure.

PubMed

Taya, Masanobu; Amiya, Eisuke; Hatano, Masaru; Maki, Hisataka; Nitta, Daisuke; Saito, Akihito; Tsuji, Masaki; Hosoya, Yumiko; Minatsuki, Shun; Nakayama, Atsuko; Fujiwara, Takayuki; Konishi, Yuto; Yokota, Kazuhiko; Watanabe, Masafumi; Morita, Hiroyuki; Haga, Nobuhiko; Komuro, Issei

2018-01-15

This study investigated the effectiveness and safety of interval training during in-hospital treatment of patients with advanced heart failure. Twenty-four consecutive patients with advanced symptomatic heart failure who were referred for cardiac transplant evaluation were recruited. After performing aerobic exercise for approximate intensity, high-intensity interval training (HIIT) was performed. The protocol consisted of 3 or 4 sessions of 1-min high-intensity exercise aimed at 80% of peak VO 2 or 80% heart rate reserve, followed by 4-min recovery periods of low intensity. In addition to the necessary laboratory data, hand grip strength and knee extensor strength were evaluated at the start of exercise training and both at the start and the end of HIIT. Knee extensor strength was standardized by body weight. The BNP level at the start of exercise training was 432 (812) pg/mL and it significantly decreased to 254 (400) pg/mL (p < 0.001) at the end of HIIT. Hand grip strength did not change during course. By contrast, knee extensor strength significantly increased during HIIT [4.42 ± 1.43 → 5.28 ± 1.45 N/kg, p < 0.001], whereas the improvement of knee extensor strength was not significant from the start of exercise training to the start of HIIT. In addition, the change in knee extensor strength during HIIT was significantly associated with the hemoglobin A1c level at the start of exercise (R = - 0.55; p = 0.015). HIIT has a positive impact on skeletal muscle strength among in-hospital patients with advanced heart failure.

Effects of gamma oryzanol supplementation on anthropometric measurements & muscular strength in healthy males following chronic resistance training.

PubMed

Eslami, Saghar; Esa, Norhaizan Mohd; Marandi, Seyed Mohammad; Ghasemi, Gholamali; Eslami, Sepehr

2014-06-01

Enhanced muscle strength is seen when resistance exercise is combined with the consumption of nutritional supplements. Although there is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans, but its usage as a nutritional supplement for strength is common in athletes. The aim of this study was to determine the effects of gamma oryzanol supplementation during 9-week resistance training on muscular strength and anthropometric measurements of young healthy males. In this double-blind clinical trial, changes of anthropometric measurements and muscular strength were studied after chronic resistance exercise and gamma oryzanol supplementation in 30 healthy volunteers (16 in supplement and 14 in placebo). Each day, gamma oryzanol supplement (600 mg) and placebo (the same amount of lactose) were consumed after training. The participants exercised with 80 per cent 1-Repetition Maximum (1-RM), for one hour and four days/week. Anthropometric measurements and subjects' 1-RM for muscular strength were determined at the commencement and end of the 9-week study. There was no significant difference between the baseline characteristics and target variables at baseline between the two groups. After gamma oryzanol supplementation, there was no significant difference in the means of anthropometric and skin fold measurements between the supplement and placebo groups. However, there were significant differences between the supplement and placebo groups for 1-RM of bench press and leg curl, which showed that gamma oryzanol improved muscle strength following resistance training. Our findings indicated that 600 mg/day gamma oryzanol supplementation during the 9-week resistance training did not change anthropometric and body measurements, but it increased muscular strength in young healthy males. Further, studies need to be done in trained athletes, women, and in patients who suffer from muscular fatigue.

The Effect of Different Resistance Training Load Schemes on Strength and Body Composition in Trained Men

PubMed Central

Lopes, Charles Ricardo; Aoki, Marcelo Saldanha; Crisp, Alex Harley; de Mattos, Renê Scarpari; Lins, Miguel Alves; da Mota, Gustavo Ribeiro; Schoenfeld, Brad Jon; Marchetti, Paulo Henrique

2017-01-01

Abstract The purpose of this study was to evaluate the impact of moderate-load (10 RM) and low-load (20 RM) resistance training schemes on maximal strength and body composition. Sixteen resistance-trained men were randomly assigned to 1 of 2 groups: a moderate-load group (n = 8) or a low-load group (n = 8). The resistance training schemes consisted of 8 exercises performed 4 times per week for 6 weeks. In order to equate the number of repetitions performed by each group, the moderate load group performed 6 sets of 10 RM, while the low load group performed 3 sets of 20 RM. Between-group differences were evaluated using a 2-way ANOVA and independent t-tests. There was no difference in the weekly total load lifted (sets × reps × kg) between the 2 groups. Both groups equally improved maximal strength and measures of body composition after 6 weeks of resistance training, with no significant between-group differences detected. In conclusion, both moderate-load and low-load resistance training schemes, similar for the total load lifted, induced a similar improvement in maximal strength and body composition in resistance-trained men. PMID:28828088

Short- and Long-Term Effects of Concurrent Strength and HIIT Training in Octogenarians with COPD.

PubMed

Guadalupe-Grau, Amelia; Aznar-Laín, Susana; Mañas, Asier; Castellanos, Juan; Alcázar, Julián; Ara, Ignacio; Mata, Esmeralda; Daimiel, Rosa; García-García, Francisco José

2017-01-01

To investigate the short- and long-term effects of concurrent strength and high-intensity interval training (HIIT) on octogenarian COPD patients, nine males (age = 84.2 ± 2.8 years, BMI = 29.3 ± 2.3) with low to severe COPD levels (2.1 ± 1.5 BODE index) underwent a supervised 9-week strength and HIIT exercise program. Training had a significant (p < .05) impact on senior fitness test scores (23-45%), 30-m walking speed (from 1.29 ± 0.29-1.62 ± 0.33 m/s), leg and chest press 1RM (38% and 45% respectively), maximal isometric strength (30-35%), and 6-min walking test (from 286.1 ± 107.2-396.2 ± 106.5 m), and tended to increase predicted forced vital capacity by 14% (p = .07). One year after the intervention all training-induced gains returned to their preintervention values except for the chest press 1RM (p <.05). Short-term concurrent strength and HIIT training increases physical fitness in the oldest-old COPD patients, and has potential long-term benefits.

Simulation of longitudinal dynamics of a freight train operating through a car dumper

NASA Astrophysics Data System (ADS)

Kovalev, R.; Sakalo, A.; Yazykov, V.; Shamdani, A.; Bowey, R.; Wakeling, C.

2016-06-01

A heavy haul train and car dumper model was created to analyse train longitudinal dynamics during dumping. Influence of such factors as performance curve of draft gears, total free slack in couplers, operating mode of train positioner and braking of last two cars of train on the in-train forces was considered.

Effects of Inspiratory Muscle Training and Calisthenics-and-Breathing Exercises in COPD With and Without Respiratory Muscle Weakness.

PubMed

Basso-Vanelli, Renata P; Di Lorenzo, Valéria A Pires; Labadessa, Ivana G; Regueiro, Eloisa M G; Jamami, Mauricio; Gomes, Evelim L F D; Costa, Dirceu

2016-01-01

Patients with COPD may experience respiratory muscle weakness. Two therapeutic approaches to the respiratory muscles are inspiratory muscle training and calisthenics-and-breathing exercises. The aims of the study are to compare the effects of inspiratory muscle training and calisthenics-and-breathing exercises associated with physical training in subjects with COPD as an additional benefit of strength and endurance of the inspiratory muscles, thoracoabdominal mobility, physical exercise capacity, and reduction in dyspnea on exertion. In addition, these gains were compared between subjects with and without respiratory muscle weakness. 25 subjects completed the study: 13 composed the inspiratory muscle training group, and 12 composed the calisthenics-and-breathing exercises group. Subjects were assessed before and after training by spirometry, measurements of respiratory muscle strength and test of inspiratory muscle endurance, thoracoabdominal excursion measurements, and the 6-min walk test. Moreover, scores for the Modified Medical Research Council dyspnea scale were reported. After intervention, there was a significant improvement in both groups of respiratory muscle strength and endurance, thoracoabdominal mobility, and walking distance in the 6-min walk test. Additionally, there was a decrease of dyspnea in the 6-min walk test peak. A difference was found between groups, with higher values of respiratory muscle strength and thoracoabdominal mobility and lower values of dyspnea in the 6-min walk test peak and the Modified Medical Research Council dyspnea scale in the inspiratory muscle training group. In the inspiratory muscle training group, subjects with respiratory muscle weakness had greater gains in inspiratory muscle strength and endurance. Both interventions increased exercise capacity and decreased dyspnea during physical effort. However, inspiratory muscle training was more effective in increasing inspiratory muscle strength and endurance, which could result in a decreased sensation of dyspnea. In addition, subjects with respiratory muscle weakness that performed inspiratory muscle training had higher gains in inspiratory muscle strength and endurance but not of dyspnea and submaximal exercise capacity. (ClinicalTrials.gov registration NCT01510041.). Copyright © 2016 by Daedalus Enterprises.

Improving the Q:H strength ratio in women using plyometric exercises.

PubMed

Tsang, Kavin K W; DiPasquale, Angela A

2011-10-01

Plyometric training programs have been implemented in anterior cruciate ligament injury prevention programs. Plyometric exercises are designed to aid in the improvement of muscle strength and neuromuscular control. Our purpose was to examine the effects of plyometric training on lower leg strength in women. Thirty (age = 20.3 ± 1.9 years) recreationally active women were divided into control and experimental groups. The experimental group performed a plyometric training program for 6 weeks, 3 d·wk(-1). All subjects attended 4 testing sessions: before the start of the training program and after weeks 2, 4, and 6. Concentric quadriceps and hamstring strength (dominant leg) was assessed using an isokinetic dynamometer at speeds of 60 and 120°·s(-1). Peak torque, average peak torque, and average power (AvgPower) were measured. The results revealed a significant (p < 0.05) interaction between time and group for flexion PkTq and AvgPower at 120°·s(-1). Post hoc analysis further revealed that PkTq at 120°·s(-1) was greater in the plyometric group than in the control group at testing session 4 and that AvgPower was greater in the plyometric group than in the control group in testing sessions 2-4. Our results indicate that the plyometric training program increased hamstring strength while maintaining quadriceps strength, thereby improving the Q:H strength ratio.

Perspectives on Aerobic and Strength Influences on Military Physical Readiness: Report of an International Military Physiology Roundtable.

PubMed

Friedl, Karl E; Knapik, Joseph J; Häkkinen, Keijo; Baumgartner, Neal; Groeller, Herbert; Taylor, Nigel A S; Duarte, Antonio F A; Kyröläinen, Heikki; Jones, Bruce H; Kraemer, William J; Nindl, Bradley C

2015-11-01

Physical fitness training of military recruits is an enduring focus of armies. This is important for safe and effective performance of general tasks that anyone may have to perform in a military setting as well as preparation for more specialized training in specific job specialties. Decades of studies on occupationally specific physical requirements have characterized the dual aerobic and strength demands of typical military tasks; however, scientifically founded strategies to prepare recruits with a good mix of these 2 physiologically opposing capabilities have not been well established. High levels of aerobic training can compromise resistance training gains and increase injury rates. Resistance training requires a greater commitment of time and resources as well as a greater understanding of the science to produce true strength gains that may be beneficial to military performance. These are critical issues for modern armies with increased demands for well-prepared soldiers and fewer injury losses. The actual physical requirements tied to metrics of success in military jobs are also under renewed examination as women are increasingly integrated into military jobs previously performed only by men. At the third International Congress on Soldiers' Physical Performance, a roundtable of 10 physiologists with military expertise presented comparative perspectives on aerobic and strength training. These topics included the physiological basis of training benefits, how to train effectively, how to measure training effectiveness, considerations for the integration of women, and the big perspective. Key discussion points centered on (a) the significance of findings from research on integrated training, (b) strategies for effective strength development, and (c) injury reduction in training as well as the benefits of improved fitness to injury reduction across the force.

Breaking of axial symmetry in excited heavy nuclei as identified in giant dipole resonance data

DOE PAGES

Grosse, E.; Junghans, A. R.; Massarczyk, R.

2017-11-28

Here, a recent theoretical prediction of a breaking of axial symmetry in quasi all heavy nuclei is confronted to a new critical analysis of photon strength functions of nuclei in the valley of stability. For the photon strength in the isovector giant dipole resonance (IVGDR) regime a parameterization of GDR shapes by the sum of three Lorentzians (TLO) is extrapolated to energies below and above the IVGDR. The impact of non-GDR modes adding to the low energy slope of photon strength is discussed including recent data on photon scattering and other radiative processes. These are shown to be concentrated inmore » energy regions where various model calculations predict intermediate collective strength; thus they are obviously separate from the IVGDR tail. The triple Lorentzian (TLO) ansatz for giant dipole resonances is normalized in accordance to the dipole sum rule. The nuclear droplet model with surface dissipation accounts well for positions and widths without local, nuclide specific, parameters. Very few and only global parameters are needed when a breaking of axial symmetry already in the valley of stability is admitted and hence a reliable prediction for electric dipole strength functions also outside of it is expected.« less

Breaking of axial symmetry in excited heavy nuclei as identified in giant dipole resonance data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grosse, E.; Junghans, A. R.; Massarczyk, R.

Here, a recent theoretical prediction of a breaking of axial symmetry in quasi all heavy nuclei is confronted to a new critical analysis of photon strength functions of nuclei in the valley of stability. For the photon strength in the isovector giant dipole resonance (IVGDR) regime a parameterization of GDR shapes by the sum of three Lorentzians (TLO) is extrapolated to energies below and above the IVGDR. The impact of non-GDR modes adding to the low energy slope of photon strength is discussed including recent data on photon scattering and other radiative processes. These are shown to be concentrated inmore » energy regions where various model calculations predict intermediate collective strength; thus they are obviously separate from the IVGDR tail. The triple Lorentzian (TLO) ansatz for giant dipole resonances is normalized in accordance to the dipole sum rule. The nuclear droplet model with surface dissipation accounts well for positions and widths without local, nuclide specific, parameters. Very few and only global parameters are needed when a breaking of axial symmetry already in the valley of stability is admitted and hence a reliable prediction for electric dipole strength functions also outside of it is expected.« less

Does on-water resisted rowing increase or maintain lower-body strength?

PubMed

Lawton, Trent W; Cronin, John B; McGuigan, Michael R

2013-07-01

Over the past 30 years, endurance volumes have increased by >20% among the rowing elite; therefore, informed decisions about the value of weight training over other possible activities in periodized training plans for rowing need to be made. The purpose of this study was to quantify the changes in lower-body strength development after two 14-week phases of intensive resisted on-water rowing, either incorporating weight training or rowing alone. Ten elite women performed 2 resisted rowing ("towing ropes," e.g., 8 × 3 minutes) plus 6 endurance (e.g., 16-28 km at 70-80% maximum heart rate) and 2 rate-regulated races (e.g., 8,000 m at 24 strokes per minute) on-water each week. After a 4-week washout phase, the 14-week phase was repeated with the addition of 2 weight-training sessions (e.g., 3-4 sets × 6-15 reps). Percent (±SD) and standardized differences in effects (effect size [ES] ± 90% confidence limit) for 5-repetition leg pressing and isometric pulling strength were calculated from data ratio scaled for body mass, log transformed and adjusted for pretest scores. Resisted rowing alone did not increase leg pressing (-1.0 ± 5.3%, p = 0.51) or isometric pulling (5.3 ± 13.4%, p = 0.28) strength. In contrast, after weight training, a moderately greater increase in leg pressing strength was observed (ES = 0.72 ± 0.49, p = 0.03), although differences in isometric pulling strength were unclear (ES = 0.56 ± 1.69, p = 0.52). In conclusion, intensive on-water training including resisted rowing maintained but did not increase lower-body strength. Elite rowers or coaches might consider the incorporation of high-intensity nonfatiguing weight training concurrent to endurance exercise if increases in lower-body strength without changes in body mass are desired.

Proton Testing: Opportunities, Pitfalls and Puzzles

NASA Technical Reports Server (NTRS)

Ladbury, Raymond

2017-01-01

Although proton SEE testing can place constraints on some heavy-ion SEE susceptibilities, it is important to quantify residual risk that protons may not reveal all SEE susceptibilities in a system. We examine the relative strengths and limitations of proton and heavy-ion SEE testing and how these may be affected by technology scaling and high-Z materials in the device.

Relationship between quadriceps strength and rate of loading during gait in women.

PubMed

Mikesky, A E; Meyer, A; Thompson, K L

2000-03-01

One function of skeletal muscle is to serve as the body's shock absorbers and thus dampen rates of loading during activity. The aim of this cross-sectional study was to determine the significance of muscle strength on rates of loading during gait. Thirty-seven women (mean age: 34.5 +/- 8.2 years) were solicited by advertisement and placed into one of two groups-strength-trained or sedentary-on the basis of training history. They walked (10 trials) over a 10-m walkway at a controlled speed of 1.22-1.35 m/s while the rate of loading was sampled with a 1,000-Hz force platform. Quadriceps and hamstring strength was measured at 90 degrees/s with an isokinetic dynamometer. Statistical analyses (p < 0.05) included descriptive statistics and unpaired t tests for comparison between groups. The women in the sedentary group weighed more and had significantly less concentric and eccentric strength of the quadriceps and hamstrings relative to body weight than did those in the strength-trained group. In addition, they demonstrated significantly higher rates of loading (2.21 +/- 0.15 compared with 1.75 +/- 0.08%wt/ms) than those in the strength-trained group.

Effectiveness of acute in-hospital physiotherapy with knee-extension strength training in reducing strength deficits in patients with a hip fracture: A randomised controlled trial

PubMed Central

2017-01-01

Question Is acute in-hospital physiotherapy with additional progressive knee-extension strength training (ST) of the fractured limb more effective in reducing knee-extension strength deficit at follow-up compared to physiotherapy without strength training in patients with a hip fracture? Design Assessor blinded, randomised controlled trial with intention-to-treat analysis. Participants 90 patients with a hip fracture admitted to an acute orthopaedic Hip Fracture Unit at a university hospital between October 2013 and May 2015. Intervention Daily physiotherapy with or without progressive knee-extension strength training (10RM), 3 x 10 repetitions, of the fractured limb using ankle weight cuffs conducted by ward physical therapists during hospital stay. Outcome measures Primary outcome was the change in maximal isometric knee-extension strength in the fractured limb in percentage of the non-fractured limb from inclusion to postoperative day 10 or discharge (follow-up). Secondary outcome was Timed Up and Go test measured early after surgery and at follow-up. Results In the intention-to-treat analysis of between-group differences, the primary outcome improved 8.1% (95% CI -2.3; 18.4) by additional strength training from baseline to follow-up. In the per-protocol analysis of non-missing data, significant between-group improvements by 10.5% (95% CI 0.3; 20.7) were found in favour of additional ST. No significant between-group differences were found in any secondary outcome. Conclusion Physiotherapy with addition of 5 sessions of ST yielded no additional improvements compared to physiotherapy without strength training in reducing the knee-extension strength deficit at follow-up in patients with a hip fracture. It is debatable whether larger improvements than the observed 8–10% can be expected given that only five exercise sessions, on average, were completed. In fragile patients with a hip fracture in the acute phase, where the ability to participate in functional exercise is compromised, we still consider early strength training a possibility to improve outcomes of clinical importance, given the results of the per-protocol analysis. The present data provides an important basis and call for future investigations including longer term interventions. Trial registration Clinicaltrials.gov NCT00848913 PMID:28662153

Key Strengths of an Innovative Volunteer Training Workshop

ERIC Educational Resources Information Center

Sellick, Angelika; Bournot-Trites, Monique; Reeder, Ken; Scales, Andrew; Smith, Mark; Zappa-Hollman, Sandra

2011-01-01

The study involved 14 volunteer facilitators, four UBC staff members, and the researcher as participant; the data collected were observation notes, questionnaires, results from focus groups, and interviews. The study revealed that the key strengths of the training workshop lay in its approach to training, its focus on confidence and capacity…

Influence of age, sex, and strength training on human muscle gene expression determined by microarray

PubMed Central

ROTH, STEPHEN M.; FERRELL, ROBERT E.; PETERS, DAVID G.; METTER, E. JEFFREY; HURLEY, BEN F.; ROGERS, MARC A.

2010-01-01

The purpose of this study was to determine the influence of age, sex, and strength training (ST) on large-scale gene expression patterns in vastus lateralis muscle biopsies using high-density cDNA microarrays and quantitative PCR. Muscle samples from sedentary young (20–30 yr) and older (65–75 yr) men and women (5 per group) were obtained before and after a 9-wk unilateral heavy resistance ST program. RNA was hybridized to cDNA filter microarrays representing ~4,000 known human genes and comparisons were made among arrays to determine differential gene expression as a result of age and sex differences, and/or response to ST. Sex had the strongest influence on muscle gene expression, with differential expression (>1.7-fold) observed for ~200 genes between men and women (~75% with higher expression in men). Age contributed to differential expression as well, as ~50 genes were identified as differentially expressed (>1.7-fold) in relation to age, representing structural, metabolic, and regulatory gene classes. Sixty-nine genes were identified as being differentially expressed (>1.7-fold) in all groups in response to ST, and the majority of these were downregulated. Quantitative PCR was employed to validate expression levels for caldesmon, SWI/SNF (BAF60b), and four-and-a-half LIM domains 1. These significant differences suggest that in the analysis of skeletal muscle gene expression issues of sex, age, and habitual physical activity must be addressed, with sex being the most critical variable. PMID:12209020

Influence of frequency and duration of strength training for effective management of neck and shoulder pain: a randomised controlled trial.

PubMed

Andersen, Christoffer H; Andersen, Lars L; Gram, Bibi; Pedersen, Mogens Theisen; Mortensen, Ole Steen; Zebis, Mette Kreutzfeldt; Sjøgaard, Gisela

2012-11-01

Specific strength training can reduce neck and shoulder pain in office workers, but the optimal combination of exercise frequency and duration remains unknown. This study investigates how one weekly hour of strength training for the neck and shoulder muscles is most effectively distributed. A total of 447 office workers with and without neck and/or shoulder pain were randomly allocated at the cluster-level to one of four groups; 1×60 (1WS), 3×20 (3WS) or 9×7 (9WS) min a week of supervised high-intensity strength training for 20 weeks, or to a reference group without training (REF). Primary outcome was self-reported neck and shoulder pain (scale 0-9) and secondary outcome work disability (Disability in Arms, Shoulders and Hands (DASH)). The intention-to-treat analysis showed reduced neck and right shoulder pain in the training groups after 20 weeks compared with REF. Among those with pain ≥3 at baseline (n=256), all three training groups achieved significant reduction in neck pain compared with REF (p<0.01). From a baseline pain rating of 3.2 (SD 2.3) in the neck among neck cases, 1WS experienced a reduction of 1.14 (95% CI 0.17 to 2.10), 3WS 1.88 (0.90 to 2.87) and 9WS 1.35 (0.24 to 2.46) which is considered clinically significant. DASH was reduced in 1WS and 3WS only. One hour of specific strength training effectively reduced neck and shoulder pain in office workers. Although the three contrasting training groups showed no statistical differences in neck pain reduction, only 1WS and 3WS reduced DASH. This study suggests some flexibility regarding time-wise distribution when implementing specific strength training at the workplace.

Effect of high-intensity home-based respiratory muscle training on strength of respiratory muscles following a stroke: a protocol for a randomized controlled trial.

PubMed

Menezes, Kênia Kiefer Parreiras De; Nascimento, Lucas Rodrigues; Polese, Janaine Cunha; Ada, Louise; Teixeira-Salmela, Luci Fuscaldi

Respiratory muscle training has shown to increase strength of the respiratory muscles following a stroke. However, low duration and/or intensity of training may be responsible for the small effect size seen and/or absence of carry-over effects to an activity, e.g., walking. Therefore, an investigation of the effects of long-duration, high-intensity respiratory muscle training is warranted. This proposed protocol for a randomized clinical trial will examine the efficacy of high-intensity respiratory muscle training to increase strength and improve activity following a stroke. This study will be a two-arm, prospectively registered, randomized controlled trial, with blinded assessors. Thirty-eight individuals who have suffered a stroke will participate. The experimental group will undertake a 40-min of respiratory muscle training program, seven days/week, for eight weeks in their homes. Training loads will be increased weekly. The control group will undertake a sham respiratory muscle training program with equivalent duration and scheduling of training. The primary outcome will be the strength of the inspiratory muscles, measured as maximal inspiratory pressure. Secondary outcomes will include expiratory muscle strength, inspiratory muscle endurance, dyspnea, respiratory complications, and walking capacity. Outcomes will be collected by a researcher blinded to group allocation at baseline (Week 0), after intervention (Week 8), and one month beyond intervention (Week 12). High-intensity respiratory muscle training may have the potential to optimize the strength of the respiratory muscles following a stroke. If benefits are carried over to activity, the findings may have broader implications, since walking capacity has been shown to predict physical activity and community participation on this population. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

Undulatory physical resistance training program increases maximal strength in elderly type 2 diabetics

PubMed Central

dos Santos, Gilberto Monteiro; Montrezol, Fábio Tanil; Pauli, Luciana Santos Souza; Sartori-Cintra, Angélica Rossi; Colantonio, Emilson; Gomes, Ricardo José; Marinho, Rodolfo; de Moura, Leandro Pereira; Pauli, José Rodrigo

2014-01-01

Objective To investigate the effects of a specific protocol of undulatory physical resistance training on maximal strength gains in elderly type 2 diabetics. Methods The study included 48 subjects, aged between 60 and 85 years, of both genders. They were divided into two groups: Untrained Diabetic Elderly (n=19) with those who were not subjected to physical training and Trained Diabetic Elderly (n=29), with those who were subjected to undulatory physical resistance training. The participants were evaluated with several types of resistance training’s equipment before and after training protocol, by test of one maximal repetition. The subjects were trained on undulatory resistance three times per week for a period of 16 weeks. The overload used in undulatory resistance training was equivalent to 50% of one maximal repetition and 70% of one maximal repetition, alternating weekly. Statistical analysis revealed significant differences (p<0.05) between pre-test and post-test over a period of 16 weeks. Results The average gains in strength were 43.20% (knee extension), 65.00% (knee flexion), 27.80% (supine sitting machine), 31.00% (rowing sitting), 43.90% (biceps pulley), and 21.10% (triceps pulley). Conclusion Undulatory resistance training used with weekly different overloads was effective to provide significant gains in maximum strength in elderly type 2 diabetic individuals. PMID:25628192

Effect of 8 weeks of free-weight and machine-based strength training on strength and power performance

PubMed Central

Wirth, Klaus; Hartmann, Hagen; Sander, Andre; Mickel, Christoph

2016-01-01

Abstract The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development) were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p < 0.001), while in the squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p < 0.001). The maximal isometric force showed no statistically significant result for the repeated measures factor, while the rate of force development of the squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance. PMID:28149424

Effect of 8 weeks of free-weight and machine-based strength training on strength and power performance.

PubMed

Wirth, Klaus; Keiner, Michael; Hartmann, Hagen; Sander, Andre; Mickel, Christoph

2016-12-01

The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development) were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p < 0.001), while in the squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p < 0.001). The maximal isometric force showed no statistically significant result for the repeated measures factor, while the rate of force development of the squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.

Influence of previous experience on resistance training on reliability of one-repetition maximum test.

PubMed

Ritti-Dias, Raphael Mendes; Avelar, Ademar; Salvador, Emanuel Péricles; Cyrino, Edilson Serpeloni

2011-05-01

The 1-repetition maximum test (1RM) has been widely used to assess maximal strength. However, to improve accuracy in assessing maximal strength, several sessions of the 1RM test are recommended. The aim of this study was to analyze the influence of previous resistance training experience on the reliability of 1RM test. Thirty men were assigned to the following 2 groups according to their previous resistance training experience: no previous resistance training experience (NOEXP) and more than 24 months of resistance training experience (EXP). All subjects performed the 1RM tests in bench press and squat in 4 sessions on distinct days. There was a significant session × group effect in bench press (F = 3.09; p < 0.03) and squat (F = 2.76; p < 0.05) showing that only the NOEXP increased maximal strength between the sessions. Significant increases (p < 0.05) in maximal strength occurred in the NOEXP between session 1 and the other sessions in bench press (session 1 vs. 2 = +3.8%; session 1 vs. 3 = +7.4%; session 1 vs. 4 = +10.1%), and squat (session 1 vs. 2 = +7.6%; session 1 vs. 3 = +10.1%; session 1 vs. 4 = +11.2%). Moreover, in bench press, maximal strength in sessions 3 and 4 were significantly higher than in session 2. The results of the present study suggest that the reliability of the 1RM test is influenced by the subject's previous experience in resistance training. Subjects without experience in resistance training require more practice and familiarization and show greater increases in maximal strength between sessions than subjects with previous experience in resistance training.

Influence of strength training intensity on subsequent recovery in elderly.

PubMed

Orssatto, L B R; Moura, B M; Bezerra, E S; Andersen, L L; Oliveira, S N; Diefenthaeler, F

2018-06-01

Understanding the influence of strength training intensity on subsequent recovery in elderly is important to avoid reductions in physical function during the days following training. Twenty-two elderly were randomized in two groups: G70 (65.9 ± 4.8 years, n = 11) and G95 (66.9 ± 5.1, n = 11). Baseline tests included maximum voluntary isometric contraction (peak torque and rate of torque development - RTD), countermovement jump, and functional capacity (timed up and go, stairs ascent and descent). Then, both groups performed a single strength training session with intensities of 70% (G70) or 95% (G95) of five repetition maximum. The same tests were repeated immediately, 24 h, 48 h, and 72 h after the session. Peak torque was lower than baseline immediately after for both groups and at 24 h for G95. Compared with G70, G95 had lower peak torque at 24 h and 48 h. Countermovement jump, timed up and go, stairs ascent, and RTD at 0-50 ms only differed from baseline immediately after for both groups. RTD at 0-200 ms was lower than baseline immediately after and 24 h after the session for both groups. In conclusion, reduced physical function immediately after strength training can last for 1-2 days in elderly depending on the type of physical function and intensity of training. Higher intensity resulted in greater impairment. Exercise prescription in elderly should take this into account, e.g., by gradually increasing intensity during the first months of strength training. These results have relevance for elderly who have to be fit for work or other activities in the days following strength training. Copyright © 2018 Elsevier Inc. All rights reserved.

Running injuries in novice runners enrolled in different training interventions: a pilot randomized controlled trial.

PubMed

Baltich, J; Emery, C A; Whittaker, J L; Nigg, B M

2017-11-01

The purpose of this trial was to evaluate injury risk in novice runners participating in different strength training interventions. This was a pilot randomized controlled trial. Novice runners (n = 129, 18-60 years old, <2 years recent running experience) were block randomized to one of three groups: a "resistance" strength training group, a "functional" strength training group, or a stretching "control" group. The primary outcome was running related injury. The number of participants with complaints and the injury rate (IR = no. injuries/1000 running hours) were quantified for each intervention group. For the first 8 weeks, participants were instructed to complete their training intervention three to five times a week. The remaining 4 months was a maintenance period. NCT01900262. A total of 52 of the 129 (40%) novice runners experienced at least one running related injury: 21 in the functional strength training program, 16 in the resistance strength training program and 15 in the control stretching program. Injury rates did not differ between study groups [IR = 32.9 (95% CI 20.8, 49.3) in the functional group, IR = 31.6 (95% CI 18.4, 50.5) in the resistance group, and IR = 26.7 (95% CI 15.2, 43.2)] in the control group. Although this was a pilot assessment, home-based strength training did not appear to alter injury rates compared to stretching. Future studies should consider methods to minimize participant drop out to allow for the assessment of injury risk. Injury risk in novice runners based on this pilot study will inform the development of future larger studies investigating the impact of injury prevention interventions. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The Effect of Instability Training on Knee Joint Proprioception and Core Strength

PubMed Central

Cuğ, Mutlu; Ak, Emre; Özdemir, Recep Ali; Korkusuz, Feza; Behm, David G

2012-01-01

Although there are many studies demonstrating increased trunk activation under unstable conditions, it is not known whether this increased activation would translate into meaningful trunk strength with a prolonged training program. Additionally, while balance-training programs have been shown to improve stability, their effect on specific joint proprioception is not clear. Thus the objective of this study was to examine training adaptations associated with a 10-week instability-training program. Participants were tested pre- and post-training for trunk extension and flexion strength and knee proprioception. Forty-three participants participated in either a 10-week (3 days per week) instability-training program using Swiss balls and body weight as resistance or a control group (n = 17). The trained group increased (p < 0. 05) trunk extension peak torque/body weight (23.6%) and total work output (20.1%) from pre- to post-training while the control group decreased by 6.8% and 6.7% respectively. The exercise group increased their trunk flexion peak torque/body weight ratios by 18.1% while the control group decreased by 0.4%. Knee proprioception (combined right and left joint repositioning) improved 44.7% from pre- to post-training (p = 0.0006) and persisted (21.5%) for 9 months post-training. In addition there was a side interaction with the position sense of the right knee at 9 months showing 32.1% (p = 0.03) less deviation from the reference angle than the right knee during pre-testing. An instability-training program using Swiss balls with body weight as resistance can provide prolonged improvements in joint proprioception and core strength in previously untrained individuals performing this novel training stress which would contribute to general health. Key pointsAlthough traditional free weight resistance exercises have been recommended as most beneficial for improving strength and power in athletes (Behm et al., 2010b), an IT program using Swiss balls and body weight as a resistance may provide an alternative starting point for the sedentary untrained population.As it is well documented that force or strength is decreased when unbalanced (Behm et al., 2010b) and balance-training programs improve balance (Behm and Kean 2006), this type of instability RT program can provide significant adaptations to improve trunk strength especially with the untrained.This type of training should also be incorporated into a new program as the improvements in joint proprioception may help protect from joint injuries over a protracted period.The finding that improved joint proprioception persists for months after training should be emphasized to those individuals whose training is regularly or inconsistently interrupted. PMID:24149355

Strength Training: A Natural Prescription for Staying Healthy and Fit.

ERIC Educational Resources Information Center

Adams, Raymond, Ed.

2003-01-01

This newsletter highlights the importance of strength training in keeping older adults healthy and fit, explaining how it can forestall declines in strength and muscle mass, along with their attendant negative impact upon other metabolic functions and activities of daily living. Physical inactivity is common throughout the nation. Approximately 11…

Comparison of Strength Gains in Untrained College-Age Females Using Free Weights and Freemotion Machines

ERIC Educational Resources Information Center

Milton, Katherine; Wojcik, Janet R.; Boyd, Joni M.; Bowers, Charles J.

2018-01-01

Resistance training has become a preferred method for developing muscular strength among various populations. A variety of resistance training modes are available, but there are mixed outcomes regarding strength development among barbells, dumbbells, and weight machines. The purpose of this study was to investigate the differences in strength…

Effect of Wiihabilitation on strength ratio of ankle muscles in adults

PubMed Central

Khalil, Aya A.; Mohamed, Ghada A.; El Rahman, Soheir M. Abd; Elhafez, Salam M.; Nassif, Nagui S.

2016-01-01

[Purpose] This study was conducted to investigate the effect of Wiihabilitation on the ankle dorsiflexion/plantar flexion strength ratio in adults. [Subjects and Methods] Thirty-two healthy male volunteers were randomly assigned to two equal groups (experimental and control). Participants in the experimental group received a Wiihabilitation training program for six weeks. Data were collected using a Biodex system 3 Isokinetic dynamometer. Peak torques of the dorsiflexors and plantar flexors were measured at an angular velocity of 60°/sec which in turn were used to derive the ankle dorsiflexion/plantar flexion strength ratio. [Results] The mean values of the ankle dorsiflexion/plantar flexion strength ratio decreased significantly between before and after the training in the experimental group, meanwhile there was no significant difference between before and after the training period in the control group . [Conclusion] Wiihabilitation has an impact on the ankle dorsiflexion/plantar flexion strength ratio, so it can be considered an effective training tool in terms of the ankle strength ratio. Thus, it could be recommended for both prevention and rehabilitation of ankle instability patients. PMID:27821951

Effect of Wiihabilitation on strength ratio of ankle muscles in adults.

PubMed

Khalil, Aya A; Mohamed, Ghada A; El Rahman, Soheir M Abd; Elhafez, Salam M; Nassif, Nagui S

2016-10-01

[Purpose] This study was conducted to investigate the effect of Wiihabilitation on the ankle dorsiflexion/plantar flexion strength ratio in adults. [Subjects and Methods] Thirty-two healthy male volunteers were randomly assigned to two equal groups (experimental and control). Participants in the experimental group received a Wiihabilitation training program for six weeks. Data were collected using a Biodex system 3 Isokinetic dynamometer. Peak torques of the dorsiflexors and plantar flexors were measured at an angular velocity of 60°/sec which in turn were used to derive the ankle dorsiflexion/plantar flexion strength ratio. [Results] The mean values of the ankle dorsiflexion/plantar flexion strength ratio decreased significantly between before and after the training in the experimental group, meanwhile there was no significant difference between before and after the training period in the control group . [Conclusion] Wiihabilitation has an impact on the ankle dorsiflexion/plantar flexion strength ratio, so it can be considered an effective training tool in terms of the ankle strength ratio. Thus, it could be recommended for both prevention and rehabilitation of ankle instability patients.

The effects of exercise on muscle strength, body composition, physical functioning and the inflammatory profile of older adults: a systematic review.

PubMed

Liberman, Keliane; Forti, Louis N; Beyer, Ingo; Bautmans, Ivan

2017-01-01

This systematic review reports the most recent literature regarding the effects of physical exercise on muscle strength, body composition, physical functioning and inflammation in older adults. All articles were assessed for methodological quality and where possible effect size was calculated. Thirty-four articles were included - four involving frail, 24 healthy and five older adults with a specific disease. One reported on both frail and nonfrail patients. Several types of exercise were used: resistance training, aerobic training, combined resistance training and aerobic training and others. In frail older persons, moderate-to-large beneficial exercise effects were noted on inflammation, muscle strength and physical functioning. In healthy older persons, effects of resistance training (most frequently investigated) on inflammation or muscle strength can be influenced by the exercise modalities (intensity and rest interval between sets). Muscle strength seemed the most frequently used outcome measure, with moderate-to-large effects obtained regardless the exercise intervention studied. Similar effects were found in patients with specific diseases. Exercise has moderate-to-large effects on muscle strength, body composition, physical functioning and inflammation in older adults. Future studies should focus on the influence of specific exercise modalities and target the frail population more.

Effects of Whole-body Vibration Training on Sprint Running Kinematics and Explosive Strength Performance

PubMed Central

Giorgos, Paradisis; Elias, Zacharogiannis

2007-01-01

The aim of this study was to investigate the effect of 6 wk of whole body vibration (WBV) training on sprint running kinematics and explosive strength performance. Twenty-four volunteers (12 women and 12 men) participated in the study and were randomised (n = 12) into the experimental and control groups. The WBV group performed a 6-wk program (16-30 min·d-1, 3 times a week) on a vibration platform. The amplitude of the vibration platform was 2.5 mm and the acceleration was 2.28 g. The control group did not participate in any training. Tests were performed Pre and post the training period. Sprint running performance was measured during a 60 m sprint where running time, running speed, step length and step rate were calculated. Explosive strength performance was measured during a counter movement jump (CMJ) test, where jump height and total number of jumps performed in a period of 30 s (30CVJT). Performance in 10 m, 20 m, 40 m, 50 m and 60 m improved significantly after 6 wk of WBV training with an overall improvement of 2.7%. The step length and running speed improved by 5.1% and 3.6%, and the step rate decreased by 3.4%. The countermovement jump height increased by 3.3%, and the explosive strength endurance improved overall by 7.8%. The WBV training period of 6 wk produced significant changes in sprint running kinematics and explosive strength performance. Key pointsWBV training.Sprint running kinematics.Explosive strength performance PMID:24149223

Ten-week Whole-body Vibration Training Improves Body Composition and Muscle Strength in Obese Women

PubMed Central

Milanese, Chiara; Piscitelli, Francesco; Zenti, Maria Grazia; Moghetti, Paolo; Sandri, Marco; Zancanaro, Carlo

2013-01-01

This work explored the short-term effect of whole body vibration (WBV) training on anthropometry, body composition and muscular strength in obese women. Fifty obese women (age=46.8±7.81[SD]y; BMI=35.1±3.55kg/m2) were assigned to a ten-week WBV training period, two times a week (in each session, 14min vibration training, 5min rest; vibration amplitude 2.0-5.0mm, frequency 40-60Hz), with (n=18) or without (n=17) radiofrequency, or to a non-exercise control group (n=15). Subjects were instructed not to change their habitual lifestyle. Before and after the ten-week experimental period, anthropometric measurements, dual-energy X-ray absorptiometry (DXA), and the leg press, leg curl and leg extension strength tests were carried out. All changes in the two groups of WBV training, with or without radiofrequency, were similar and these groups were combined in a single WBV intervention group. As compared to controls, subjects submitted to WBV training had significantly lower BMI, total body and trunk fat, sum of skinfolds and body circumferences. On the other hand, lower limb strength tests were increased in the WBV group. These preliminary results suggest that WBV training may improve body composition and muscular strength in obese women and may be a useful adjuvant to lifestyle prescriptions. PMID:23423629

Feasibility of resistance training in adult McArdle patients: clinical outcomes and muscle strength and mass benefits.

PubMed

Santalla, Alfredo; Munguía-Izquierdo, Diego; Brea-Alejo, Lidia; Pagola-Aldazábal, Itziar; Díez-Bermejo, Jorge; Fleck, Steven J; Ara, Ignacio; Lucia, Alejandro

2014-01-01

We analyzed the effects of a 4-month resistance (weight lifting) training program followed by a 2-month detraining period in 7 adult McArdle patients (5 female) on: muscle mass (assessed by DXA), strength, serum creatine kinase (CK) activity and clinical severity. Adherence to training was ≥84% in all patients and no major contraindication or side effect was noted during the training or strength assessment sessions. The training program had a significant impact on total and lower extremities' lean mass (P < 0.05 for the time effect), with mean values increasing with training by +855 g (95% confidence interval (CI): 30, 1679) and +547 g (95%CI: 116, 978), respectively, and significantly decreasing with detraining. Body fat showed no significant changes over the study period. Bench press and half-squat performance, expressed as the highest value of average muscle power (W) or force (N) in the concentric-repetition phase of both tests showed a consistent increase over the 4-month training period, and decreased with detraining. Yet muscle strength and power detraining values were significantly higher than pre-training values, indicating that a training effect was still present after detraining. Importantly, all the participants, with no exception, showed a clear gain in muscle strength after the 4-month training period, e.g., bench press: +52 W (95% CI: 13, 91); half-squat: +173 W (95% CI: 96, 251). No significant time effect (P > 0.05) was noted for baseline or post strength assessment values of serum CK activity, which remained essentially within the range reported in our laboratory for McArdle patients. All the patients changed to a lower severity class with training, such that none of them were in the highest disease severity class (3) after the intervention and, as such, they did not have fixed muscle weakness after training. Clinical improvements were retained, in all but one patient, after detraining, such that after detraining all patients were classed as class 1 for disease severity.

Effects of freeze-thaw on characteristics of new KMP binder stabilized Zn- and Pb-contaminated soils.

PubMed

Wei, Ming-Li; Du, Yan-Jun; Reddy, Krishna R; Wu, Hao-Liang

2015-12-01

For viable and sustainable reuse of solidified/stabilized heavy metal-contaminated soils as roadway subgrade materials, long-term durability of these soils should be ensured. A new binder, KMP, has been developed for solidifying/stabilizing soils contaminated with high concentrations of heavy metals. However, the effects of long-term extreme weather conditions including freeze and thaw on the leachability and strength of the KMP stabilized contaminated soils have not been investigated. This study presents a systematic investigation on the impacts of freeze-thaw cycle on leachability, strength, and microstructural characteristics of the KMP stabilized soils spiked with Zn and Pb individually and together. For comparison purpose, Portland cement is also tested as a conventional binder. Several series of tests are conducted including the toxicity characteristic leaching procedure (TCLP), modified European Community Bureau of Reference (BCR) sequential extraction procedure, unconfined compression test (UCT), and mercury intrusion porosimetry (MIP). The results demonstrate that the freeze-thaw cycles have much less impact on the leachability and strength of the KMP stabilized soils as compared to the PC stabilized soils. After the freeze-thaw cycle tests, the KMP stabilized soils display much lower leachability, mass loss, and strength loss. These results are assessed based on the chemical speciation of Zn and Pb, and pore size distribution of the soils. Overall, this study demonstrates that the KMP stabilized heavy metal-contaminated soils perform well under the freeze-thaw conditions.

Strength and coordination training are both effective in reducing the postural tremor amplitude of older adults.

PubMed

Keogh, Justin W L; Morrison, Steve; Barrett, Rod

2010-01-01

The current study investigated the effect of 2 different types of unilateral resistance training on the postural tremor output of 19 neurologically healthy men age 70-80 yr. The strength- (n = 7) and coordination-training (n = 7) groups trained twice a week for 6 wk, performing dumbbell biceps curls, wrist flexions, and wrist extensions, while the control group (n = 5) maintained their normal activities. Changes in index-finger tremor (RMS amplitude, peak, and proportional power) and upper limb muscle coactivation were assessed during 4 postural conditions that were performed separately with the trained and untrained limbs. The 2 training groups experienced significantly greater reductions in mean RMS tremor amplitude, peak, and proportional tremor power 8-12 Hz and upper limb muscle coactivation, as well as greater increases in strength, than the control group. These results further demonstrate the benefits of resistance training for improving function in older adults.

Interaction of Beta-Hydroxy-Beta-Methylbutyrate Free Acid and Adenosine Triphosphate on Muscle Mass, Strength, and Power in Resistance Trained Individuals.

PubMed

Lowery, Ryan P; Joy, Jordan M; Rathmacher, John A; Baier, Shawn M; Fuller, John C; Shelley, Mack C; Jäger, Ralf; Purpura, Martin; Wilson, Stephanie M C; Wilson, Jacob M

2016-07-01

Lowery, RP, Joy, JM, Rathmacher, JA, Baier, SM, Fuller, JC Jr, Shelley, MC II, Jäger, R, Purpura, M, Wilson, SMC, and Wilson, JM. Interaction of beta-hydroxy-beta-methylbutyrate free acid and adenosine triphosphate on muscle mass, strength, and power in resistance trained individuals. J Strength Cond Res 30(7): 1843-1854, 2016-Adenosine-5'-triphosphate (ATP) supplementation helps maintain performance under high fatiguing contractions and with greater fatigue recovery demands also increase. Current evidence suggests that the free acid form of β-hydroxy-β-methylbutyrate (HMB-FA) acts by speeding regenerative capacity of skeletal muscle after high-intensity or prolonged exercise. Therefore, we investigated the effects of 12 weeks of HMB-FA (3 g) and ATP (400 mg) administration on lean body mass (LBM), strength, and power in trained individuals. A 3-phase double-blind, placebo-, and diet-controlled study was conducted. Phases consisted of an 8-week periodized resistance training program (phase 1), followed by a 2-week overreaching cycle (phase 2), and a 2-week taper (phase 3). Lean body mass was increased by a combination of HMB-FA/ATP by 12.7% (p < 0.001). In a similar fashion, strength gains after training were increased in HMB-FA/ATP-supplemented subjects by 23.5% (p < 0.001). Vertical jump and Wingate power were increased in the HMB-FA/ATP-supplemented group compared with the placebo-supplemented group, and the 12-week increases were 21.5 and 23.7%, respectively. During the overreaching cycle, strength and power declined in the placebo group (4.3-5.7%), whereas supplementation with HMB-FA/ATP resulted in continued strength gains (1.3%). In conclusion, HMB-FA and ATP in combination with resistance exercise training enhanced LBM, power, and strength. In addition, HMB-FA plus ATP blunted the typical response to overreaching, resulting in a further increase in strength during that period. It seems that the combination of HMB-FA/ATP could benefit those who continuously train at high levels such as elite athletes or military personnel.

Review of Modelling Techniques for In Vivo Muscle Force Estimation in the Lower Extremities during Strength Training

PubMed Central

Schellenberg, Florian; Oberhofer, Katja; Taylor, William R.

2015-01-01

Background. Knowledge of the musculoskeletal loading conditions during strength training is essential for performance monitoring, injury prevention, rehabilitation, and training design. However, measuring muscle forces during exercise performance as a primary determinant of training efficacy and safety has remained challenging. Methods. In this paper we review existing computational techniques to determine muscle forces in the lower limbs during strength exercises in vivo and discuss their potential for uptake into sports training and rehabilitation. Results. Muscle forces during exercise performance have almost exclusively been analysed using so-called forward dynamics simulations, inverse dynamics techniques, or alternative methods. Musculoskeletal models based on forward dynamics analyses have led to considerable new insights into muscular coordination, strength, and power during dynamic ballistic movement activities, resulting in, for example, improved techniques for optimal performance of the squat jump, while quasi-static inverse dynamics optimisation and EMG-driven modelling have helped to provide an understanding of low-speed exercises. Conclusion. The present review introduces the different computational techniques and outlines their advantages and disadvantages for the informed usage by nonexperts. With sufficient validation and widespread application, muscle force calculations during strength exercises in vivo are expected to provide biomechanically based evidence for clinicians and therapists to evaluate and improve training guidelines. PMID:26417378

Strength training in community settings: impact of lay leaders on program access and sustainability for rural older adults.

PubMed

Washburn, Lisa T; Cornell, Carol E; Phillips, Martha; Felix, Holly; Traywick, LaVona

2014-09-01

The effect of volunteer lay leaders on availability and sustainability of strength-training programs for older adults has not been well explored. We describe implementation of the StrongWomen strength training program by the Arkansas Cooperative Extension Service, and report on the relationship between delivery approach (agent-led, lay-led, or combination of agent- and lay-led) and program access and sustainability. All state Extension agents (n = 66) were surveyed on program implementation, continuance, and use of lay leaders. Program records were used to identify the number of trained lay leaders. Regression models were used to examine the relationship between delivery approach and group availability. Counties using lay leaders had twice as many groups as counties using only agents. There was a significant, positive relationship between the number of lay leaders and the number of groups. Counties using lay leaders were 8.3 times more likely to have continuing groups compared with counties not using lay leaders. Program continuance was significantly and positively associated with lay leader use. Lay delivery expanded access to strength training programs and increased the likelihood that programs would continue. This approach can be used to increase access to and sustainability of strength training programs, particularly in resource-constrained areas.

Review of Modelling Techniques for In Vivo Muscle Force Estimation in the Lower Extremities during Strength Training.

PubMed

Schellenberg, Florian; Oberhofer, Katja; Taylor, William R; Lorenzetti, Silvio

2015-01-01

Knowledge of the musculoskeletal loading conditions during strength training is essential for performance monitoring, injury prevention, rehabilitation, and training design. However, measuring muscle forces during exercise performance as a primary determinant of training efficacy and safety has remained challenging. In this paper we review existing computational techniques to determine muscle forces in the lower limbs during strength exercises in vivo and discuss their potential for uptake into sports training and rehabilitation. Muscle forces during exercise performance have almost exclusively been analysed using so-called forward dynamics simulations, inverse dynamics techniques, or alternative methods. Musculoskeletal models based on forward dynamics analyses have led to considerable new insights into muscular coordination, strength, and power during dynamic ballistic movement activities, resulting in, for example, improved techniques for optimal performance of the squat jump, while quasi-static inverse dynamics optimisation and EMG-driven modelling have helped to provide an understanding of low-speed exercises. The present review introduces the different computational techniques and outlines their advantages and disadvantages for the informed usage by nonexperts. With sufficient validation and widespread application, muscle force calculations during strength exercises in vivo are expected to provide biomechanically based evidence for clinicians and therapists to evaluate and improve training guidelines.

Protective Effects of Psychological Strengths Against Psychiatric Disorders Among Soldiers.

PubMed

Shrestha, Alice; Cornum, B G Rhonda; Vie, Loryana L; Scheier, Lawrence M; Lester, M A J Paul B; Seligman, Martin E P

2018-03-01

This study prospectively examined psychological strengths targeted in U.S. Army training programs as predictors of psychiatric diagnosis in active duty soldiers. At baseline, the cohort (140,584 soldiers) was without psychiatric disorder. Soldiers were then followed for 2 yr and classified as healthy, or acquiring a psychiatric diagnosis (adjustment disorder, anxiety disorder, depression, or post-traumatic stress disorder), or being prescribed psychotropic medication without a psychiatric diagnosis. Soldiers who remained healthy reported significantly higher strengths scores at baseline, compared with soldiers who were diagnosed with a psychiatric disorder. In addition, soldiers in the worst strengths decile were twice as likely to develop a psychiatric disorder, compared with soldiers in the top 50% on baseline strengths. Strengths afforded the greatest protection against depression. Offering tailored resilience training programs could help the Army steel vulnerable soldiers against the challenges of life, military training, and combat.

Effect of speed endurance and strength training on performance, running economy and muscular adaptations in endurance-trained runners.

PubMed

Vorup, Jacob; Tybirk, Jonas; Gunnarsson, Thomas P; Ravnholt, Tanja; Dalsgaard, Sarah; Bangsbo, Jens

2016-07-01

To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate (1 × week(-1)) intensity training with a reduction in total volume of ~58 %, whereas CON continued their training (~45 km week(-1)). In CSS, 400-m and Yo-Yo intermittent recovery test performance was improved by 5 % (P < 0.01) and 19 % (P < 0.001), respectively, during the intervention period. Maximal aerobic speed was 0.6 km h(-1) higher (P < 0.05), and maximal activity of lactate dehydrogenase subunits 1 and 2 was 17 % (P < 0.05) higher after compared to before the intervention period. Time to exhaustion and peak blood lactate during an incremental treadmill test was 9 % (P < 0.05) and 32 % (P < 0.01), respectively, higher and expression of Na(+)-K(+) pump β1 subunit was 15 % higher (P < 0.05) after compared to before the intervention period. 10-K performance, maximum oxygen uptake and running economy were unchanged. In CON, no changes were observed. Adding strength and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.

Comparison of In-Season-Specific Resistance vs. A Regular Throwing Training Program on Throwing Velocity, Anthropometry, and Power Performance in Elite Handball Players.

PubMed

Hermassi, Souhail; van den Tillaar, Roland; Khlifa, Riadh; Chelly, Mohamed Souhaiel; Chamari, Karim

2015-08-01

The purpose of this study was to compare the effect of a specific resistance training program (throwing movement with a medicine ball) with that of regular training (throwing with regular balls) on ball velocity, anthropometry, maximal upper-body strength, and power. Thirty-four elite male team handball players (age: 18 ± 0.5 years, body mass: 80.6 ± 5.5 kg, height: 1.80 ± 5.1 m, body fat: 13.4 ± 0.6%) were randomly assigned to 1 of the 3 groups: control (n = 10), resistance training group (n = 12), or regular throwing training group (n = 12). Over the 8-week in season, the athletes performed 3 times per week according to an assigned training program alongside their normal team handball training. One repetition maximum (1RM) bench press and 1RM pullover scores assessed maximal arm strength. Anthropometry was assessed by body mass, fat percentage, and muscle volumes of upper body. Handball throwing velocity was measured by a standing throw, a throw with run, and a jump throw. Power was measured by measuring total distance thrown by a 3-kg medicine ball overhead throw. Throwing ball velocity, maximal strength, power, and muscle volume increases for the specific resistance training group after the 8 weeks of training, whereas only maximal strength, muscle volume and power and in the jump throw increases were found for the regular throwing training group. No significant changes for the control group were found. The current findings suggest that elite male handball players can improve ball velocity, anthropometrics, maximal upper-body strength, and power during the competition season by implementing a medicine ball throwing program.

Effect of Sequencing Strength and Endurance Training in Young Male Soccer Players.

PubMed

Makhlouf, Issam; Castagna, Carlo; Manzi, Vincenzo; Laurencelle, Louis; Behm, David G; Chaouachi, Anis

2016-03-01

This study examined the effects of strength and endurance training sequence (strength before or after endurance) on relevant fitness variables in youth soccer players. Fifty-seven young elite-level male field soccer players (13.7 ± 0.5 years; 164 ± 8.3 cm; 53.5 ± 8.6 kg; body fat; 15.6 ± 3.9%) were randomly assigned to a control (n = 14, CG) and 3 experimental training groups (twice a week for 12 weeks) strength before (SE, n = 15), after (ES, n = 14) or on alternate days (ASE, n = 14) with endurance training. A significant (p = 0.001) intervention main effect was detected. There were only trivial training sequence differences (ES vs. SE) for all variables (p > 0.05). The CG showed large squat 1 repetition maximum (1RM) and medium sprint, change of direction ability, and jump improvements. ASE demonstrated a trivial difference in endurance performance with ES and SE (p > 0.05). Large to medium greater improvements for SE and ES were reported compared with ASE for sprinting over 10 and 30 m (p < 0.02). The SE squat 1RM was higher than in ASE (moderate, p < 0.02). Postintervention differences between ES and SE with CG fitness variables were small to medium (p ≤ 0.05) except for a large SE advantage with the Yo-Yo intermittent recovery test (p < 0.001, large). This study showed no effect of intrasession training sequence on soccer fitness-relevant variables. However, combining strength and endurance within a single training session provided superior results vs. training on alternate days. Concurrent training may be considered as an effective and safe training method for the development of the prospective soccer player.

Effects of In-Season Explosive Strength Training on Maximal Leg Strength, Jumping, Sprinting, and Intermittent Aerobic Performance in Male Handball Athletes.

PubMed

Hermassi, Souhail; Chelly, Mohamed Souhaiel; Fieseler, Georg; Bartels, Thomas; Schulze, Stephan; Delank, Karl-Stefan; Shephard, Roy J; Schwesig, René

2017-09-01

Background  Team handball is an intense ball sport with specific requirements on technical skills, tactical understanding, and physical performance. The ability of handball players to develop explosive efforts (e. g. sprinting, jumping, changing direction) is crucial to success. Objective  The purpose of this pilot study was to examine the effects of an in-season high-intensity strength training program on the physical performance of elite handball players. Materials and methods  Twenty-two handball players (a single national-level Tunisian team) were randomly assigned to a control group (CG; n = 10) or a training group (TG; n = 12). At the beginning of the pilot study, all subjects performed a battery of motor tests: one repetition maximum (1-RM) half-squat test, a repeated sprint test [6 × (2 × 15 m) shuttle sprints], squat jumps, counter movement jumps (CMJ), and the Yo-Yo intermittent recovery test level 1. The TG additionally performed a maximal leg strength program twice a week for 10 weeks immediately before engaging in regular handball training. Each strength training session included half-squat exercises to strengthen the lower limbs (80 - 95 % of 1-RM, 1 - 3 repetitions, 3 - 6 sets, 3 - 4 min rest between sets). The control group underwent no additional strength training. The motor test battery was repeated at the end of the study interventions. Results  In the TG, 3 parameters (maximal strength of lower limb: η² = 0.74; CMJ: η² = 0.70, and RSA best time: η² = 0.25) showed significant improvements, with large effect sizes (e. g. CMJ: d = 3.77). A reduction in performance for these same 3 parameters was observed in the CG (d = -0.24). Conclusions  The results support our hypothesis that additional strength training twice a week enhances the maximal strength of the lower limbs and jumping or repeated sprinting performance. There was no evidence of shuttle sprints ahead of regular training compromising players' speed and endurance capacities. © Georg Thieme Verlag KG Stuttgart · New York.

Sarcopenia and decreased muscle strength in the elderly woman: resistance training as a safe and effective intervention.

PubMed

Foster-Burns, S B

1999-01-01

A principle component of age-related weakness and frailty in women is sarcopenia. This decrease in skeletal muscle mass is a progressive syndrome that will affect the quality of life for elderly women by decreasing the ability to perform many activities of daily living. Strength training is known to be an effective means of increasing muscular strength and size in many populations, and can be utilized successfully to significantly improve muscle strength, muscle mass and functional mobility in elderly women up to the age of 96 years. Such exercise can minimize the syndrome of physical frailty due to decreased muscle mass and strength. Any rehabilitation or exercise program for the elderly woman would benefit from the inclusion of such a training regime.

Policy analysis of the budget used in training program for reducing lower back pain among heavy equipment operators in the construction industry: System dynamics approach

NASA Astrophysics Data System (ADS)

Vitharana, V. H. P.; Chinda, T.

2018-04-01

Lower back pain (LBP), prevalence is high among the heavy equipment operators leading to high compensation cost in the construction industry. It is found that proper training program assists in reducing chances of having LBP. This study, therefore aims to examine different safety related budget available to support LBP related training program for different age group workers, utilizing system dynamics modeling approach. The simulation results show that at least 2.5% of the total budget must be allocated in the safety and health budget to reduce the chances of having LBP cases.

High-load strength training improves outcome in patients with plantar fasciitis: A randomized controlled trial with 12-month follow-up.

PubMed

Rathleff, M S; Mølgaard, C M; Fredberg, U; Kaalund, S; Andersen, K B; Jensen, T T; Aaskov, S; Olesen, J L

2015-06-01

The aim of this study was to investigate the effectiveness of shoe inserts and plantar fascia-specific stretching vs shoe inserts and high-load strength training in patients with plantar fasciitis. Forty-eight patients with ultrasonography-verified plantar fasciitis were randomized to shoe inserts and daily plantar-specific stretching (the stretch group) or shoe inserts and high-load progressive strength training (the strength group) performed every second day. High-load strength training consisted of unilateral heel raises with a towel inserted under the toes. Primary outcome was the foot function index (FFI) at 3 months. Additional follow-ups were performed at 1, 6, and 12 months. At the primary endpoint, at 3 months, the strength group had a FFI that was 29 points lower [95% confidence interval (CI): 6-52, P = 0.016] compared with the stretch group. At 1, 6, and 12 months, there were no differences between groups (P > 0.34). At 12 months, the FFI was 22 points (95% CI: 9-36) in the strength group and 16 points (95% CI: 0-32) in the stretch group. There were no differences in any of the secondary outcomes. A simple progressive exercise protocol, performed every second day, resulted in superior self-reported outcome after 3 months compared with plantar-specific stretching. High-load strength training may aid in a quicker reduction in pain and improvements in function. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

National Strength and Conditioning Association Position Statement: Health Aspects of Resistance Exercise and Training.

ERIC Educational Resources Information Center

Conley, Michael S.; Rozenek, Ralph

2001-01-01

Resistance training may enhance cardiovascular health, improve body composition, increase bone mineral density, reduce anxiety and depression, reduce the risk of injury during other sports, and increase muscular strength and endurance. The paper describes the effects of resistance training on: the cardiovascular system, energy expenditure and body…

Strength Training and Detraining in Different Populations: Case Studies

PubMed Central

Marques, Mário C.; Zajac, Adam; Pereira, Ana; Costa, Aldo M.

2011-01-01

Many researchers have demonstrated that a specific strength training program can improve maximal strength and, the rate of force production, reduce the incidence of muscle-skeletal injury, and contribute to faster injury recovery times, thereby minimizing the number of missed practice sessions or competitions. Yet, to our best knowledge, there is no apparent consensus on the appropriate method of muscle strength and power training to enhance performance in distinct populations groups. Interruptions in training process because of illness, injury, holidays, post-season break or other factors are normal situations in any kind of sport. However, the detraining period and its consequences are not well reported in sports literature, and namely during puberty. Therefore, the aim of this paper was to discuss several case studies concerning different populations such us physical students, age-swimming competitors and elite power athletes. PMID:23487418

A Randomized Trial Comparing Two Tongue-Pressure Resistance Training Protocols for Post-Stroke Dysphagia.

PubMed

Steele, Catriona M; Bayley, Mark T; Peladeau-Pigeon, Melanie; Nagy, Ahmed; Namasivayam, Ashwini M; Stokely, Shauna L; Wolkin, Talia

2016-06-01

The objective of this study was to compare the outcomes of two tongue resistance training protocols. One protocol ("tongue-pressure profile training") emphasized the pressure-timing patterns that are typically seen in healthy swallows by focusing on gradual pressure release and saliva swallowing tasks. The second protocol ("tongue-pressure strength and accuracy training") emphasized strength and accuracy in tongue-palate pressure generation and did not include swallowing tasks. A prospective, randomized, parallel allocation trial was conducted. Of 26 participants who were screened for eligibility, 14 received up to 24 sessions of treatment. Outcome measures of posterior tongue strength, oral bolus control, penetration-aspiration and vallecular residue were made based on videofluoroscopy analysis by blinded raters. Complete data were available for 11 participants. Significant improvements were seen in tongue strength and post-swallow vallecular residue with thin liquids, regardless of treatment condition. Stage transition duration (a measure of the duration of the bolus presence in the pharynx prior to swallow initiation, which had been chosen to capture impairments in oral bolus control) showed no significant differences. Similarly, significant improvements were not seen in median scores on the penetration-aspiration scale. This trial suggests that tongue strength can be improved with resistance training for individuals with tongue weakness following stroke. We conclude that improved penetration-aspiration does not necessarily accompany improvements in tongue strength; however, tongue-pressure resistance training does appear to be effective for reducing thin liquid vallecular residue.

A comparison of strength-training, self-management and the combination for early osteoarthritis of the knee

PubMed Central

McKnight, Patrick E.; Kasle, Shelley; Going, Scott; Villaneuva, Isidro; Cornett, Michelle; Farr, Josh; Wright, Jill; Streeter, Clara; Zautra, Alex

2010-01-01

Objective To assess the relative effectiveness of combining self-management and strength-training for improving functional outcomes in early knee osteoarthritis patients. Methods A randomized intervention trial lasting 24 months conducted at an academic medical center. Community dwelling middle-aged adults (N=273), aged 34 to 65 with knee osteoarthritis, pain and self-reported physical disability completed a strength-training program, a self-management program, or a combined program. Outcomes included five physical function tests (leg press, range of motion, work capacity, balance, and stair climbing) and two self-reported measures of pain and disability. Results A total of 201 (73.6 %) participants completed the 2-year trial. Overall compliance was modest - strength-training (55.8 %), self-management (69.1 %), and combined (59.6 %) programs. The three groups showed a significant and large increase from pre- to post-treatment in all physical functioning measures including leg press (d =.85), range of motion (d=1.00), work capacity (d=.60), balance (d=.59), and stair climbing (d=.59). Additionally, all three groups showed decreased self-reported pain (d=-.51) and disability (d=-.55). There were no significant differences among groups. Conclusions Middle-aged, sedentary persons with mild early knee osteoarthritis benefited from strength-training, self-management, and the combination. These results suggest that both strength-training and self-management are suitable treatments for early onset of knee osteoarthritis in middle-aged adults. Self-management alone may offer the least burdensome treatment for early osteoarthritis. PMID:20191490

Effects of core strength training using stable versus unstable surfaces on physical fitness in adolescents: a randomized controlled trial.

PubMed

Granacher, Urs; Schellbach, Jörg; Klein, Katja; Prieske, Olaf; Baeyens, Jean-Pierre; Muehlbauer, Thomas

2014-01-01

It has been demonstrated that core strength training is an effective means to enhance trunk muscle strength (TMS) and proxies of physical fitness in youth. Of note, cross-sectional studies revealed that the inclusion of unstable elements in core strengthening exercises produced increases in trunk muscle activity and thus provide potential extra training stimuli for performance enhancement. Thus, utilizing unstable surfaces during core strength training may even produce larger performance gains. However, the effects of core strength training using unstable surfaces are unresolved in youth. This randomized controlled study specifically investigated the effects of core strength training performed on stable surfaces (CSTS) compared to unstable surfaces (CSTU) on physical fitness in school-aged children. Twenty-seven (14 girls, 13 boys) healthy subjects (mean age: 14 ± 1 years, age range: 13-15 years) were randomly assigned to a CSTS (n = 13) or a CSTU (n = 14) group. Both training programs lasted 6 weeks (2 sessions/week) and included frontal, dorsal, and lateral core exercises. During CSTU, these exercises were conducted on unstable surfaces (e.g., TOGU© DYNAIR CUSSIONS, THERA-BAND© STABILITY TRAINER). Significant main effects of Time (pre vs. post) were observed for the TMS tests (8-22%, f = 0.47-0.76), the jumping sideways test (4-5%, f = 1.07), and the Y balance test (2-3%, f = 0.46-0.49). Trends towards significance were found for the standing long jump test (1-3%, f = 0.39) and the stand-and-reach test (0-2%, f = 0.39). We could not detect any significant main effects of Group. Significant Time x Group interactions were detected for the stand-and-reach test in favour of the CSTU group (2%, f = 0.54). Core strength training resulted in significant increases in proxies of physical fitness in adolescents. However, CSTU as compared to CSTS had only limited additional effects (i.e., stand-and-reach test). Consequently, if the goal of training is to enhance physical fitness, then CSTU has limited advantages over CSTS. ClinicalTrials.gov Identifier: NCT02290457 Registered 13 November 2014.

Mixed-Methods Resistance Training Increases Power and Strength of Young and Older Men.

ERIC Educational Resources Information Center

Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.

2002-01-01

Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…

Acute effects of heavy-load squats on consecutive squat jump performance.

PubMed

Weber, Kurt R; Brown, Lee E; Coburn, Jared W; Zinder, Steven M

2008-05-01

Postactivation potentiation (PAP) and complex training have generated interest within the strength and conditioning community in recent years, but much of the research to date has produced confounding results. The purpose of this study was to observe the acute effects of a heavy-load back squat [85% 1 repetition maximum (1RM)] condition on consecutive squat jump performance. Twelve in-season Division I male track-and-field athletes participated in two randomized testing conditions: a five-repetition back squat at 85% 1RM (BS) and a five-repetition squat jump (SJ). The BS condition consisted of seven consecutive squat jumps (BS-PRE), followed by five repetitions of the BS at 85% 1RM, followed by another set of seven consecutive squat jumps (BS-POST). The SJ condition was exactly the same as the BS condition except that five consecutive SJs replaced the five BSs, with 3 minutes' rest between each set. BS-PRE, BS-POST, SJ-PRE, and SJ-POST were analyzed and compared for mean and peak jump height, as well as mean and peak ground reaction force (GRF). The BS condition's mean and peak jump height and peak GRF increased 5.8% +/- 4.8%, 4.7% +/- 4.8%, and 4.6% +/- 7.4%, respectively, whereas the SJ condition's mean and peak jump height and peak GRF decreased 2.7% +/- 5.0%, 4.0% +/- 4.9%, and 1.3% +/- 7.5%, respectively. The results indicate that performing a heavy-load back squat before a set of consecutive SJs may enhance acute performance in average and peak jump height, as well as peak GRF.

Developing hands-on ergonomics lessons for youth

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, C; Alexandre, M; Jacobs, K

2006-02-22

By the time students are ready to enter the workforce they have been exposed to up to 20 years of ergonomics risk factors. As technology evolves, it provides more opportunities for intensive repetitive motion and with computers, cell phones, personal digital assistants (PDAs), and electronic games. The average student engages in fewer active physical activities, sit stationary in mismatched furniture in schools for hours and carry heavy backpacks. While long-term effects remain to be identified, increasingly ergonomists and others concerned with musculoskeletal health and wellness, see a need for early ergonomics education. This interactive session provides a hands-on approach tomore » introducing ergonomics to students. Although different approaches may effectively introduce ergonomics at even early stages of development, this program was designed for youth at the middle to high school age. Attendees will participate in four activities designed to introduce ergonomics at an experiential level. The modules focus on grip strength, effective breathing, optimizing your chair, and backpack safety. The workshop will include presentation and worksheets designed for use by teachers with minimal ergonomics training. Feedback from the participants will be sought for further refining the usability and safety of the training package.« less

Sport-specific nutrition: practical strategies for team sports.

PubMed

Holway, Francis E; Spriet, Lawrence L

2011-01-01

Implementation of a nutrition programme for team sports involves application of scientific research together with the social skills necessary to work with a sports medicine and coaching staff. Both field and court team sports are characterized by intermittent activity requiring a heavy reliance on dietary carbohydrate sources to maintain and replenish glycogen. Energy and substrate demands are high during pre-season training and matches, and moderate during training in the competitive season. Dietary planning must include enough carbohydrate on a moderate energy budget, while also meeting protein needs. Strength and power team sports require muscle-building programmes that must be accompanied by adequate nutrition, and simple anthropometric measurements can help the nutrition practitioner monitor and assess body composition periodically. Use of a body mass scale and a urine specific gravity refractometer can help identify athletes prone to dehydration. Sports beverages and caffeine are the most common supplements, while opinion on the practical effectiveness of creatine is divided. Late-maturing adolescent athletes become concerned about gaining size and muscle, and assessment of maturity status can be carried out with anthropometric procedures. An overriding consideration is that an individual approach is needed to meet each athlete's nutritional needs.

Effect of A 16 Week Combined Strength and Plyometric Training Program Followed by A Detraining Period on Athletic Performance in Pubertal Volleyball Players.

PubMed

Fathi, Abed; Hammami, Raouf; Moran, Jason; Borji, Rihab; Sahli, Sonia; Rebai, Haithem

2018-02-01

The purpose of this study was to determine the effects of 16 weeks of combined strength and plyometric training or plyometric training alone, and how a detraining program can modify adaptations in response to the training stimulus. Sixty male volleyball players (circa PHV:-1 to +1 years from PHV) were assigned to a Combined Training group (CTG) (n=20), a Plyometric Training group (PTG) (n=20) or a control group (CG) (n=20). The experimental groups (CTG and PTG) participated in training twice weekly for 16 weeks. Thigh muscle volume, body fat, flexibility, sprint, jump height and medicine ball throw were measured at pre-training, post-training and detraining. Respectively, the CTG and PTG showed increases in thigh muscle volume (Effect size: 0.71 and 0.42), and decreases in body fat (-0.42 and -0.34) as well as improvements in 5 m sprint (-0.69 and -0.46) 10 m sprint (-0.31 and -0.3), lower body muscle power (0.44 and 0.36) and upper body muscle power (1.32 and 0.7). After the detraining period, all groups maintained previously attained muscle power (6.79% to 9.87%; p<0.001). In conclusion, combined strength and plyometric training provided better improvements than plyometric training only. The combination of strength and plyometric training is a time-effective training modality that confers improvements in physical performance measures, muscle size and body fat. A temporary period of detraining may not undermine performance gains in pubertal volleyball players.

Comparison of low-intensity blood flow-restricted training-induced muscular hypertrophy in eumenorrheic women in the follicular phase and luteal phase and age-matched men.

PubMed

Sakamaki, Mikako; Yasuda, Tomohiro; Abe, Takashi

2012-05-01

The purpose of this study was to compare the muscle hypertrophic response in women during both the follicular (FP) and the luteal phase (LP) of their menstrual cycles following short-term, low-intensity resistance training combined with blood flow restriction (BFR). Eight eumenorrheic women and five men, all previously untrained, performed unilateral low-intensity (30% of 1 repetition maximum) dumbbell curl training with BFR once a day for 6 days. The opposite arm served as an untrained control. This 6-day training programme was conducted during both menstrual cycle phases: the early FP and the mid LP. MRI-measured biceps muscle volume (MV) and isometric elbow flexion strength were measured in both arms before and 2 days after the final training bout. Significantly (P<0.05) greater muscle hypertrophy was observed in the LP (5·7%) than in the FP (3·7%). The absolute and relative changes in serum hormone concentrations between the two phases did not correlate (P>0.05) with the percentage change in MV between the LP and FP. There was no change in MV in the control arm for both cycle phases. Following training, isometric strength increased (P<0.01) in the LP, but not in the FP (P = 0.17). Relative strength (strength per unit MV) was similar pre- and post-training in both phases. The percentage changes in MV and strength were similar between the women (average of LP and FP) and men. Our results indicate that muscle hypertrophy and strength gain are higher in the LP than in the FP following 6 days of BFR training, although the sex difference in the training response is non-existent. © 2011 The Authors. Clinical Physiology and Functional Imaging © 2011 Scandinavian Society of Clinical Physiology and Nuclear Medicine.

Comparing Performance During Morning vs. Afternoon Training Sessions in Intercollegiate Basketball Players

PubMed Central

Heishman, Aaron D.; Curtis, Michael A.; Saliba, Ethan N.; Hornett, Robert J.; Malin, Steven K.

2017-01-01

Abstract Heishman, AD, Curtis, MA, Saliba, EN, Hornett, RJ, Malin, SK, and Weltman, AL. Comparing performance during morning vs. afternoon training sessions in intercollegiate basketball players. J Strength Cond Res 31(6): 1557–1562, 2017—Time of day is a key factor that influences the optimization of athletic performance. Intercollegiate coaches oftentimes hold early morning strength training sessions for a variety of factors including convenience. However, few studies have specifically investigated the effect of early morning vs. late afternoon strength training on performance indices of fatigue. This is athletically important because circadian and/or ultradian rhythms and alterations in sleep patterns can affect training ability. Therefore, the purpose of the present study was to examine the effects of morning vs. afternoon strength training on an acute performance index of fatigue (countermovement jump height, CMJ), player readiness (Omegawave), and self-reported sleep quantity. We hypothesized that afternoon training sessions would be associated with increased levels of performance, readiness, and self-reported sleep. A retrospective analysis was performed on data collected over the course of the preseason on 10 elite National Collegiate Athletic Association Division 1 male basketball players. All basketball-related activities were performed in the afternoon with strength and conditioning activities performed either in the morning or in the afternoon. The average values for CMJ, power output (Power), self-reported sleep quantity (sleep), and player readiness were examined. When player load and duration were matched, CMJ (58.8 ± 1.3 vs. 61.9 ± 1.6 cm, p = 0.009), Power (6,378.0 ± 131.2 vs. 6,622.1 ± 172.0 W, p = 0.009), and self-reported sleep duration (6.6 ± 0.4 vs. 7.4 ± 0.25 p = 0.016) were significantly higher with afternoon strength and conditioning training, with no differences observed in player readiness values. We conclude that performance is suppressed with morning training and is associated with a decrease in self-reported quantity of sleep. PMID:28538305

Is inertial flywheel resistance training superior to gravity-dependent resistance training in improving muscle strength? A systematic review with meta-analyses.

PubMed

Vicens-Bordas, J; Esteve, E; Fort-Vanmeerhaeghe, A; Bandholm, T; Thorborg, K

2018-01-01

The primary aim of this systematic review was to determine if inertial flywheel resistance training is superior to gravity-dependent resistance training in improving muscle strength. The secondary aim was to determine whether inertial flywheel resistance training is superior to gravity-dependent resistance training in improving other muscular adaptations. A systematic review with meta-analyses of randomised and non-randomised controlled trials. We searched MEDLINE, Scopus, SPORTDiscus, Web of Science and Cochrane Central Register of Controlled Trials with no publication date restrictions until November 2016. We performed meta-analyses on randomised and non-randomised controlled trials to determine the standardized mean difference between the effects of inertial flywheel and gravity-dependent resistance training on muscle strength. A total of 76 and 71 participants were included in the primary and secondary analyses, respectively. After systematic review, we included three randomised and four non-randomised controlled trials. In the primary analysis for the primary outcome muscle strength, the pooled results from randomised controlled trials showed no difference (SMD=-0.05; 95%CI -0.51 to 0.40; p=0.82; I 2 =0%). In the secondary analyses of the primary outcome, the pooled results from non-randomised controlled trials showed no difference (SMD=0.02; 95%CI -0.45 to 0.49; p=0.93; I 2 =0%; and SMD=0.03; 95%CI -0.43 to 0.50; p=0.88; I 2 =0%). Meta-analysis on secondary outcomes could not be performed. Based on the available data, inertial flywheel resistance training was not superior to gravity-dependent resistance training in enhancing muscle strength. Data for other strength variables and other muscular adaptations was insufficient to draw firm conclusions from. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

High doses of anti-inflammatory drugs compromise muscle strength and hypertrophic adaptations to resistance training in young adults.

PubMed

Lilja, M; Mandić, M; Apró, W; Melin, M; Olsson, K; Rosenborg, S; Gustafsson, T; Lundberg, T R

2018-02-01

This study tested the hypothesis that high doses of anti-inflammatory drugs would attenuate the adaptive response to resistance training compared with low doses. Healthy men and women (aged 18-35 years) were randomly assigned to daily consumption of ibuprofen (IBU; 1200 mg; n = 15) or acetylsalicylic acid (ASA; 75 mg; n = 16) for 8 weeks. During this period, subjects completed supervised knee-extensor resistance training where one leg was subjected to training with maximal volitional effort in each repetition using a flywheel ergometer (FW), while the other leg performed conventional (work-matched across groups) weight-stack training (WS). Before and after training, muscle volume (MRI) and strength were assessed, and muscle biopsies were analysed for gene and protein expression of muscle growth regulators. The increase in m. quadriceps volume was similar between FW and WS, yet was (averaged across legs) greater in ASA (7.5%) compared with IBU (3.7%, group difference 34 cm 3 ; P = 0.029). In the WS leg, muscle strength improved similarly (11-20%) across groups. In the FW leg, increases (10-23%) in muscle strength were evident in both groups yet they were generally greater (interaction effects P < 0.05) for ASA compared with IBU. While our molecular analysis revealed several training effects, the only group interaction (P < 0.0001) arose from a downregulated mRNA expression of IL-6 in IBU. Maximal over-the-counter doses of ibuprofen attenuate strength and muscle hypertrophic adaptations to 8 weeks of resistance training in young adults. Thus, young individuals using resistance training to maximize muscle growth or strength should avoid excessive intake of anti-inflammatory drugs. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Effects of Strength Training on Postpubertal Adolescent Distance Runners.

PubMed

Blagrove, Richard C; Howe, Louis P; Cushion, Emily J; Spence, Adam; Howatson, Glyn; Pedlar, Charles R; Hayes, Philip R

2018-06-01

Strength training activities have consistently been shown to improve running economy (RE) and neuromuscular characteristics, such as force-producing ability and maximal speed, in adult distance runners. However, the effects on adolescent (<18 yr) runners remains elusive. This randomized control trial aimed to examine the effect of strength training on several important physiological and neuromuscular qualities associated with distance running performance. Participants (n = 25, 13 female, 17.2 ± 1.2 yr) were paired according to their sex and RE and randomly assigned to a 10-wk strength training group (STG) or a control group who continued their regular training. The STG performed twice weekly sessions of plyometric, sprint, and resistance training in addition to their normal running. Outcome measures included body mass, maximal oxygen uptake (V˙O2max), speed at V˙O2max, RE (quantified as energy cost), speed at fixed blood lactate concentrations, 20-m sprint, and maximal voluntary contraction during an isometric quarter-squat. Eighteen participants (STG: n = 9, 16.1 ± 1.1 yr; control group: n = 9, 17.6 ± 1.2 yr) completed the study. The STG displayed small improvements (3.2%-3.7%; effect size (ES), 0.31-0.51) in RE that were inferred as "possibly beneficial" for an average of three submaximal speeds. Trivial or small changes were observed for body composition variables, V˙O2max and speed at V˙O2max; however, the training period provided likely benefits to speed at fixed blood lactate concentrations in both groups. Strength training elicited a very likely benefit and a possible benefit to sprint time (ES, 0.32) and maximal voluntary contraction (ES, 0.86), respectively. Ten weeks of strength training added to the program of a postpubertal distance runner was highly likely to improve maximal speed and enhances RE by a small extent, without deleterious effects on body composition or other aerobic parameters.

Effects of intensive strength-power training on sense of coherence among 60-85-year-old people with hip fracture: a randomized controlled trial.

PubMed

Pakkala, Inka; Read, Sanna; Sipilä, Sarianna; Portegijs, Erja; Kallinen, Mauri; Heinonen, Ari; Alen, Markku; Kiviranta, Ilkka; Rantanen, Taina

2012-06-01

Older people with disabilities are at increased risk of psychological health decline. There are no earlier studies on the effects of resistance training on sense of coherence (SOC) among older people with a history of hip fracture. The aim of this study is to test the effects of intensive 12-week strength-power training on SOC among older adults after hip fracture. A clinical sample of 60-85-year-old community-dwelling men and women was studied, 0.5. to 7.0 years after hip fracture. Forty-six had no contraindications for participation and were randomized into training (n=24) and control groups (n=22). The training group participated in a 12-week, individually tailored, strength-power training program, twice a week in a senior gym and supervised by an experienced physiotherapist. SOC was assessed with Antonovsky's short 13-item scale. Data were collected at baseline and after intervention. Intensive 12-week strength-power training had no effect on participants' SOC level. Results indicated no change in SOC after 12-week physical exercise training among participants after hip fracture. Further studies on SOC among older people with disabilities and potential ways of increasing it are needed.

Short-Term Unilateral Resistance Training Results in Cross Education of Strength Without Changes in Muscle Size, Activation, or Endocrine Response.

PubMed

Beyer, Kyle S; Fukuda, David H; Boone, Carleigh H; Wells, Adam J; Townsend, Jeremy R; Jajtner, Adam R; Gonzalez, Adam M; Fragala, Maren S; Hoffman, Jay R; Stout, Jeffrey R

2016-05-01

Short-term unilateral resistance training results in cross education of strength without changes in muscle size, activation, or endocrine response. J Strength Cond Res 30(5): 1213-1223, 2016-The purpose of this study was to assess the cross education of strength and changes in the underlying mechanisms (muscle size, activation, and hormonal response) after a 4-week unilateral resistance training (URT) program. A group of 9 untrained men completed a 4-week URT program on the dominant leg (DOM), whereas cross education was measured in the nondominant leg (NON); and were compared with a control group (n = 8, CON). Unilateral isometric force (PKF), leg press (LP) and leg extension (LE) strength, muscle size (by ultrasonography) and activation (by electromyography) of the rectus femoris and vastus lateralis, and the hormonal response (testosterone, growth hormone, insulin, and insulin-like growth factor-1) were tested pretraining and posttraining. Group × time interactions were present for PKF, LP, LE, and muscle size in DOM and for LP in NON. In all interactions, the URT group improved significantly better than CON. There was a significant acute hormonal response to URT, but no chronic adaptation after the 4-week training program. Four weeks of URT resulted in an increase in strength and size of the trained musculature, and cross education of strength in the untrained musculature, which may occur without detectable changes in muscle size, activation, or the acute hormonal response.

Latest Development and Application of High Strength and Heavy Gauge Pipeline Steel in China

NASA Astrophysics Data System (ADS)

Yongqing, Zhang; Aimin, Guo; Chengjia, Shang; Qingyou, Liu; Gray, J. Malcolm; Barbaro, Frank

Over the past twenty years, significant advances have been made in the field of microalloying and associated application, among which one of the most successful application cases is HTP practice for heavy gauge, high strength pipeline steels. Combined the strengthening effects of TMCP and retardation effects of austenite recrystallization with increasing Nb in austenite region, HTP conception with low carbon and high niobium alloy design has been successfully applied to develop X80 coil with a thickness of 18.4mm used for China's Second West-East pipeline. During this process, big efforts were made to further develop and enrich the application of microalloying technology, and at the same time the strengthening effects of Nb have been completely unfolded and fully utilized with improved metallurgical quality and quantitative analysis of microstructure. In this paper, the existing status and strengthening effect of Nb during reheating, rolling, cooling and welding have been analyzed and characterized based on mass production samples and laboratory analysis. As confirmed, grain refinement remains the most basic strengthening measure to reduce the microstructure gradient along the thickness, which in turn enlarges the processing window to improve upon low temperature toughness, and finally make it possible to develop heavy gauge, high strength pipeline steels with more challenging fracture toughness requirements.

Sustained effect of resistance training on blood pressure and hand grip strength following a detraining period in elderly hypertensive women: a pilot study

PubMed Central

Nascimento, Dahan da Cunha; Tibana, Ramires Alsamir; Benik, Franklin M; Fontana, Keila Elizabeth; Neto, Frederico Ribeiro; de Santana, Frederico Santos; Santos-Neto, Leopoldo; Silva, Renato André Sousa; Silva, Alessandro Oliveira; Farias, Darlan Lopes; Balsamo, Sandor; Prestes, Jonato

2014-01-01

Introduction Hypertension is the most prevalent modifiable risk factor with a high prevalence among older adults. Exercise is a nonpharmacological treatment shown to benefit all patients with hypertension. Objective This study examined the effects of a 14-week moderate intensity resistance training program (RT) on the maintenance of blood pressure and hand grip strength during an extended detraining period in elderly hypertensive women. Methods Twelve hypertensive sedentary elderly women completed 14 weeks of whole body RT at a moderate perceived exertion following a detraining period of 14 weeks. Results Following the training period, participants demonstrated an increase in absolute hand grip strength (P=0.001), relative hand grip strength (P=0.032) and a decrease of systolic (P=0.001), diastolic (P=0.008), and mean blood pressure (P=0.002) when compared to pre-exercise values. In addition, these effects were sustained after 14 weeks of detraining. Conclusion Resistance training may be a valuable method to improve muscular strength and blood pressure in elderly people with benefits being maintained up to 14 weeks following training cessation. PMID:24477221

Intensive reasoning training alters patterns of brain connectivity at rest

PubMed Central

Mackey, Allyson P.; Miller Singley, Alison T.; Bunge, Silvia A.

2013-01-01

Patterns of correlated activity among brain regions reflect functionally relevant networks that are widely assumed to be stable over time. We hypothesized that if these correlations reflect the prior history of co-activation of brain regions, then a marked shift in cognition could alter the strength of coupling between these regions. We sought to test whether intensive reasoning training in humans would result in tighter coupling among regions in the lateral fronto-parietal network, as measured with resting-state fMRI (rs-fMRI). Rather than designing an artificial training program, we studied individuals who were preparing for a standardized test that places heavy demands on relational reasoning, the Law School Admissions Test (LSAT). LSAT questions require test-takers to group or sequence items according to a set of complex rules. We recruited young adults who were enrolled in an LSAT course that offers 70 hours of reasoning instruction (n=25), and age- and IQ-matched controls intending to take the LSAT in the future (n=24). Rs-fMRI data were collected for all subjects during two scanning sessions separated by 90 days. An analysis of pairwise correlations between brain regions implicated in reasoning showed that fronto-parietal connections were strengthened, along with parietal-striatal connections. These findings provide strong evidence for neural plasticity at the level of large-scale networks supporting high-level cognition. PMID:23486950

Strength and Conditioning Training by the Danish National Handball Team Before an Olympic Tournament.

PubMed

Kvorning, Thue; Hansen, Mikkel R B; Jensen, Kurt

2017-07-01

Kvorning, T, Hansen, MRB, and Jensen, K. Strength and conditioning training by the Danish national handball team before an Olympic tournament. J Strength Cond Res 31(7): 1759-1765, 2017-The physical demands imposed on national team handball teams during the Olympics imply significant physical preparation to improve performance and reduce incidence of injuries. The purpose of this case report was to describe and analyze the strength and conditioning (S&C) training performed by the Danish national handball team before the Beijing Olympic Games. Eight weeks of S&C was divided into 5 weeks emphasizing muscle hypertrophy and long-interval running followed by 3 weeks emphasizing strength, power, and short-interval running. Body mass increased by 1.6% (p < 0.05), whereas body fat decreased by 1.0% (p < 0.05). No differences were seen in countermovement jump or jump-and-reach height (p > 0.05). Agility performance was evaluated by a T-test and improved by 2.5% (p < 0.05). Changes by 6% and 22% were seen in 1 repetition maximum (1RM) bench press and 1RM back squat, respectively. However, only the 1RM bench press increased significantly (p < 0.05). Running performance was tested by the Yo-Yo intermittent recovery test, level 2, and improved by 25% (p < 0.05). In conclusion, during 8 weeks of S&C training before the Beijing Olympics, body composition changed toward more muscle mass, better upper-body strength, better interval running, and agility performance, whereas no changes were seen in jumping or lower-body muscle strength. This case report may be used as a handy script for handball teams preparing for competition. Detailed and periodized S&C training programs for 8 weeks are provided and can be used by teams ranging from moderately to highly trained.

Effects of a Modified German Volume Training Program on Muscular Hypertrophy and Strength.

PubMed

Amirthalingam, Theban; Mavros, Yorgi; Wilson, Guy C; Clarke, Jillian L; Mitchell, Lachlan; Hackett, Daniel A

2017-11-01

Amirthalingam, T, Mavros, Y, Wilson, GC, Clarke, JL, Mitchell, L, and Hackett, DA. Effects of a modified German volume training program on muscular hypertrophy and strength. J Strength Cond Res 31(11): 3109-3119, 2017-German Volume Training (GVT), or the 10 sets method, has been used for decades by weightlifters to increase muscle mass. To date, no study has directly examined the training adaptations after GVT. The purpose of this study was to investigate the effect of a modified GVT intervention on muscular hypertrophy and strength. Nineteen healthy men were randomly assign to 6 weeks of 10 or 5 sets of 10 repetitions for specific compound resistance exercises included in a split routine performed 3 times per week. Total and regional lean body mass, muscle thickness, and muscle strength were measured before and after the training program. Across groups, there were significant increases in lean body mass measures, however, greater increases in trunk (p = 0.043; effect size [ES] = -0.21) and arm (p = 0.083; ES = -0.25) lean body mass favored the 5-SET group. No significant increases were found for leg lean body mass or measures of muscle thickness across groups. Significant increases were found across groups for muscular strength, with greater increases in the 5-SET group for bench press (p = 0.014; ES = -0.43) and lat pull-down (p = 0.003; ES = -0.54). It seems that the modified GVT program is no more effective than performing 5 sets per exercise for increasing muscle hypertrophy and strength. To maximize hypertrophic training effects, it is recommended that 4-6 sets per exercise be performed, as it seems gains will plateau beyond this set range and may even regress due to overtraining.

Effects of Pelvic and Core Strength Training on High School Cross-Country Race Times.

PubMed

Clark, Anne W; Goedeke, Maggie K; Cunningham, Saengchoy R; Rockwell, Derek E; Lehecka, Bryan J; Manske, Robert C; Smith, Barbara S

2017-08-01

Clark, AW, Goedeke, MK, Cunningham, SR, Rockwell, DE, Lehecka, BJ, Manske, RC, and Smith, BS. Effects of pelvic and core strength training on high school cross-country race times. J Strength Cond Res 31(8): 2289-2295, 2017-There is only limited research examining the effect of pelvic and core strength training on running performance. Pelvic and core muscle fatigue is believed to contribute to excess motion along frontal and transverse planes which decreases efficiency in normal sagittal plane running motions. The purpose of this study was to determine whether adding a 6-week pelvic and core strengthening program resulted in decreased race times in high school cross-country runners. Thirty-five high school cross-country runners (14-19 years old) from 2 high schools were randomly assigned to a strengthening group (experimental) or a nonstrengthening group (control). All participants completed 4 standardized isometric strength tests for hip abductors, adductors, extensors, and core musculature in a test-retest design. The experimental group performed a 6-week pelvic and core strengthening program along with their normal training. Participants in the control group performed their normal training without additional pelvic and core strengthening. Baseline, 3-week, and 6-week race times were collected using a repeated measures design. No significant interaction between experimental and control groups regarding decreasing race times and increasing pelvic and core musculature strength occurred over the 6-week study period. Both groups increased strength and decreased overall race times. Clinically significant findings reveal a 6-week pelvic and core stability strengthening program 3 times a week in addition to coach led team training may help decrease race times.

Long-term effect of nutritional counselling on desired gain in body mass and lean body mass in elite athletes.

PubMed

Garthe, Ina; Raastad, Truls; Sundgot-Borgen, Jorunn

2011-08-01

Lean body mass (LBM) is important in power-related sports. In athletes with heavy training loads and competitions, it may be difficult to increase and maintain LBM during the season. The purpose of this study was to evaluate the long-term effects on body composition after an 8-12 week weight-gain period with or without nutritional guidance. Twenty-one elite athletes where randomized to 1 of 2 groups: the nutritional counselling group (NCG; n = 12, 18.5 ± 1.7 y, 67.8 ± 7.4 kg) and the ad libitum group (ALG; n = 9, 19.6 ± 2.7 y, 74.2 ± 5.7 kg). The NCG followed a meal plan that provided a surplus of 506 ± 84 kcal·day(-1), whereas the ALG had an ad libitum energy intake (EI) during the strength-training (4 sessions per week) intervention. Body mass (BM) and body composition were measured pre- and postintervention, and 6 and 12 months after the intervention. EI in the NCG was normalized after 12 months, whereas EI in the ALG was unchanged during or after the intervention. BM increased more in the NCG than in the ALG during the intervention (4.3% ± 0.9% vs. 1.0% ± 0.6%) and after 12 months (6.0% ± 0.9% vs. 1.8% ± 0.7%). LBM increased in the NCG during the intervention (2.8% ± 0.5%) and after 12 months (4.4% ± 1.0%), whereas LBM in the ALG was unchanged. The NCG managed to maintain and increase BM and LBM after the intervention period. Hence, the focus on nutritional guidance, in addition to strength training, seems to be preferable for obtaining the long-term effect of weight gain in athletes.

Heavy-metal contamination on training ranges at the Grafenwoehr Training Area, Germany

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zellmer, S.D.; Schneider, J.F.

1993-05-01

Large quantities of lead and other heavy metals are deposited in the environment of weapons ranges during training exercises. This study was conducted to determine the type, degree, and extent of heavy-metal contamination on selected handgun, rifle, and hand-grenade ranges at Grafenwoehr Training Area, Germany. Soil, vegetation, and surface-water samples were collected and analyzed using the inductively-coupled plasma atomic-emission spectroscopy (ICP-AES) method and the toxic characterization leaching procedure (TCLP). The ICP-AES results show that above-normal levels of lead and copper are in the surface soil at the handgun range, high concentrations of lead and copper are in the berm andmore » soil surface at the rifle range, and elevated levels of cadmium and above-normal concentrations of arsenic, copper, and zinc are present in the surface soil at the hand-grenade range. The TCLP results show that surface soils can be considered hazardous waste because of lead content at the rifle range and because of cadmium concentration at the hand-grenade range. Vegetation at the handgun and rifle ranges has above-normal concentrations of lead. At the hand-grenade range, both vegetation and surface water have high levels of cadmium. A hand-held X-ray fluorescence (XRF) spectrum analyzer was used to measure lead concentrations in soils in a field test of the method. Comparison of XRF readings with ICP-AES results for lead indicate that the accuracy and precision of the hand-held XRF unit must improve before the unit can be used as more than a screening tool. Results of this study show that heavy-metal contamination at all three ranges is limited to the surface soil; heavy metals are not being leached into the soil profile or transported into adjacent areas.« less

Whole-body vibration as a potential countermeasure for dynapenia and arterial stiffness.

PubMed

Figueroa, Arturo; Jaime, Salvador J; Alvarez-Alvarado, Stacey

2016-09-01

Age-related decreases in muscle mass and strength are associated with decreased mobility, quality of life, and increased cardiovascular risk. Coupled with the prevalence of obesity, the risk of death becomes substantially greater. Resistance training (RT) has a well-documented beneficial impact on muscle mass and strength in young and older adults, although the high-intensity needed to elicit these adaptations may have a detrimental or negligible impact on vascular function, specifically on arterial stiffness. Increased arterial stiffness is associated with systolic hypertension, left ventricular hypertrophy, and myocardial ischemia. Therefore, improvements of muscle strength and arterial function are important in older adults. Recently, whole-body vibration (WBV) exercise, a novel modality of strength training, has shown to exhibit similar results on muscle strength as RT in a wide-variety of populations, with the greatest impact in elderly individuals with limited muscle function. Additionally, WBV training has been shown to have beneficial effects on vascular function by reducing arterial stiffness. This article reviews relevant publications reporting the effects of WBV on muscle strength and/or arterial stiffness. Findings from current studies suggest the use of WBV training as an alternative modality to traditional RT to countermeasure the age-related detriments in muscle strength and arterial stiffness in older adults.

Effects of Menstrual Phase-Dependent Resistance Training Frequency on Muscular Hypertrophy and Strength.

PubMed

Sakamaki-Sunaga, Mikako; Min, Seokki; Kamemoto, Kayoko; Okamoto, Takanobu

2016-06-01

The present study investigated how different training frequencies during menstrual phases affect muscle hypertrophy and strength. Fourteen eumenorrheic women performed 3 sets of arm curls (8-15 repetitions) until failure for 12 weeks. Depending on the menstrual cycle phase, each subject trained each arm separately after either a 3- or a 1-d·wk training protocol during the follicular phase (FP-T) and a 3- or 1-d·wk training protocol during the luteal phase (LP-T). Cross-sectional area (CSA), 1 repetition maximum, and maximum voluntary contraction significantly increased 6.2 ± 4.4, 36.4 ± 11.9, and 16.7 ± 5.6%, respectively (p ≤ 0.05 vs. before training), in the FP-T group and 7.8 ± 4.2, 31.8 ± 14.1, and 14.9 ± 12.7%, respectively (p ≤ 0.05 vs. before training), in the LP-T group. Changes in CSA between the FP-T and the LP-T groups significantly and positively correlated (r = 0.54, p ≤ 0.05). There were no major differences among the different training protocols with regard to muscle hypertrophy and strength. Therefore, we suggest that variations in female hormones induced by the menstrual cycle phases do not significantly contribute to muscle hypertrophy and strength gains during 12 weeks of resistance training.

Heavy thunderstorms observed over land by the Nimbus 7 scanning multichannel microwave radiometer

NASA Technical Reports Server (NTRS)

Spencer, R. W.; Olson, W. S.; Martin, D. W.; Weinman, J. A.; Santek, D. A.; Wu, R.

1983-01-01

Brightness temperatures obtained through examination of microwave data from the Nimbus 7 satellite are noted to be much lower than those expected on the strength of radiation emanating from rain-producing clouds. Very cold brightness temperature cases all coincided with heavy thunderstorm rainfall, with the cold temperatures being attributable to scattering by a layer of ice hydrometeors in the upper parts of the storms. It is accordingly suggested that brightness temperatures observed by satellite microwave radiometers can sometimes distinguish heavy rain over land.

Immobilization of Chromium from Liquid Waste of Electroplating Home-Industries by Fly Ash Geopolymerization

NASA Astrophysics Data System (ADS)

Fansuri, H.; Erviana, E.; Rosyidah, M.; Iqbal, R. M.; Utomo, W. P.; Nurlina

2018-05-01

Immobilization is one of methods that can be used to overcome the problem of water pollution by heavy metals, such as chromium, which is possibly produced in an electroplating home-industry. One method that can be used to immobilize heavy metals is by using the waste water as a reactant in a geopolymerization process. The resulting geopolymer will contain such heavy metals and keep them from being dispersed into the environment. In this research, the immobilization was carried out by geopolymerization of fly ash from PT. IPMOMI (International Power Mitsui Operation and Maintenance) in Probolinggo, Indonesia, which pass through 60 (FA 60), 100 (FA 100), and 200 (FA 200) mesh sieve and using wastewater from electroplating home-industries in Ngingas Village, Sidoarjo-Indonesia, or a solution of Cr(NO3)3.9H2O as one of its reactants. The composition of the geopolymerization follows the results of previous research, i.e using the ratio of Solid to Liquid (S/L) = 3.59, Na2O/SiO2 = 0.67, H2O/Na2O = 3.33 and SiO2/Al2O3 = 6.46. Experimental results show that the compressive strength of geopolymers without heavy metals addition increases when the particle size decreases. Geopolymer made of FA 100 has the highest compressive strength i.e 35.05 MPa. The addition of a chromium-containing wastewater in FA 100 geopolymerization produce a geopolymer with a lower compressive strength i.e 26.42 MPa while the addition of Cr(NO3)3·9H2O solution produce geopolymer with compressive strength of 24.47 MPa. The SEM-EDX photo shows that chrome was evenly dispersed in the geopolymer. Leaching test with TCLP method (Toxicity Characteristic Leaching Procedure) on the geopolymer product showed that no chrome content in the leachate was found. This suggests that chromium is immobilized by geopolymers very well.

Treatment of Petroleum Sludge By Using Solidification/Stabilization (S/S) Method : Effect of Hydration Days to Heavy Metals Leaching and Strength

NASA Astrophysics Data System (ADS)

Murshid, N.; Kamil, N. A. F. M.; Kadir, A. A.

2018-04-01

Petroleum sludge is one of the major solid wastes generated in the petroleum industry. Generally, there are numbers of heavy metals in petroleum sludge and one treatment that is gaining prominence to treat a variety of mixed organic and inorganic waste is solidification/stabilization (S/S) method. The treatment protects human health and the environment by immobilizing contaminants within the treated material and prevents migration of the contaminants. In this study, solidification/stabilization (S/S) method has been used to treat the petroleum sludge. The comparison of hydration days, namely, 7th and 28th days in these cement-based waste materials were studied by using Synthetic Precipitate Leaching Procedure (SPLP). The results were compared to the United States Environmental Protection Agency (USEPA) standards. The results for leaching test concluded that less percentage OPC gave maximum concentration of heavy metals leaching due to deficient in Calcium Oxide (CaO), which is can caused weak solidification in the mixture. Physical and mechanical properties conducted such as compressive strength and density test. From the results, it shows addition up to of 30percentage PS give results which comply with minimum landfill dispose limit. The results shows correlation between strength and density are strong regression coefficient of 82.7%. In conclusion, S/S method can be alternative disposal method for PS in the same time complies with standard for minimum landfill disposal limit. The results for leaching test concluded the less OPC percentage gave maximum concentration of heavy metals leaching.

Effects of Arachidonic Acid Supplementation on Acute Anabolic Signaling and Chronic Functional Performance and Body Composition Adaptations.

PubMed

De Souza, Eduardo O; Lowery, Ryan P; Wilson, Jacob M; Sharp, Matthew H; Mobley, Christopher Brooks; Fox, Carlton D; Lopez, Hector L; Shields, Kevin A; Rauch, Jacob T; Healy, James C; Thompson, Richard M; Ormes, Jacob A; Joy, Jordan M; Roberts, Michael D

2016-01-01

The primary purpose of this investigation was to examine the effects of arachidonic acid (ARA) supplementation on functional performance and body composition in trained males. In addition, we performed a secondary study looking at molecular responses of ARA supplementation following an acute exercise bout in rodents. Thirty strength-trained males (age: 20.4 ± 2.1 yrs) were randomly divided into two groups: ARA or placebo (i.e. CTL). Then, both groups underwent an 8-week, 3-day per week, non-periodized training protocol. Quadriceps muscle thickness, whole-body composition scan (DEXA), muscle strength, and power were assessed at baseline and post-test. In the rodent model, male Wistar rats (~250 g, ~8 weeks old) were pre-fed with either ARA or water (CTL) for 8 days and were fed the final dose of ARA prior to being acutely strength trained via electrical stimulation on unilateral plantar flexions. A mixed muscle sample was removed from the exercised and non-exercised leg 3 hours post-exercise. Lean body mass (2.9%, p<0.0005), upper-body strength (8.7%, p<0.0001), and peak power (12.7%, p<0.0001) increased only in the ARA group. For the animal trial, GSK-β (Ser9) phosphorylation (p<0.001) independent of exercise and AMPK phosphorylation after exercise (p-AMPK less in ARA, p = 0.041) were different in ARA-fed versus CTL rats. Our findings suggest that ARA supplementation can positively augment strength-training induced adaptations in resistance-trained males. However, chronic studies at the molecular level are required to further elucidate how ARA combined with strength training affect muscle adaptation.

Modified Daily Undulating Periodization Model Produces Greater Performance Than a Traditional Configuration in Powerlifters.

PubMed

Zourdos, Michael C; Jo, Edward; Khamoui, Andy V; Lee, Sang-Rok; Park, Bong-Sup; Ormsbee, Michael J; Panton, Lynn B; Contreras, Robert J; Kim, Jeong-Su

2016-03-01

The primary aim of this study was to compare 2 daily undulating periodization (DUP) models on one-repetition maximum (1RM) strength in the squat, bench press, deadlift, total volume (TV) lifted, and temporal hormone response. Eighteen male, college-aged (21.1 ± 1.9 years) powerlifters participated in this study and were assigned to one of 2 groups: (a) traditional DUP training with a weekly training order: hypertrophy-specific, strength-specific, and power-specific training (HSP, n = 9) or (b) modified DUP training with a weekly training order: hypertrophy-specific, power-specific, and strength-specific training (HPS, n = 9). Both groups trained 3 nonconsecutive days per week for 6 weeks and performed the squat, bench press, and deadlift exercises. During hypertrophy and power sessions, subjects performed a fixed number of sets and repetitions but performed repetitions until failure at a given percentage during strength sessions to compare TV. Testosterone and cortisol were measured at pretesting and posttesting and before each strength-specific day. Hypertrophy, power, and strength produced greater TV in squat and bench press (p ≤ 0.05) than HSP, but not for deadlift (p > 0.05). For squat and deadlift, there was no difference between groups for 1RM (p > 0.05); however, HPS exhibited greater increases in 1RM bench press than HSP (p ≤ 0.05). Effect sizes (ES) showed meaningful differences (ES > 0.50) in favor of HPS for squat and bench press 1RM. Testosterone decreased (p ≤ 0.05) at weeks 5 and 6 and cortisol decline at weeks 3 and 4. However, neither hormone was different at posttesting compared with pretesting (p > 0.05). Our findings suggest that an HPS configuration of DUP has enhanced performance benefits compared with HSP.

Myosin heavy chain composition in the rat diaphragm - Effect of age and exercise training

NASA Technical Reports Server (NTRS)

Gosselin, Luc E.; Betlach, Michael; Vailas, Arthur C.; Greaser, Marion L.; Thomas, D. P.

1992-01-01

The effects of aging and exercise training on the myosin heavy chain (MHC) composition were determined in both the costal and crural diaphragm regions of female Fischer 344 rats. Treadmill running at 75 percent maximal oxygen consumption resulted in similar increases in plantaris muscle citrate synthase activity in both young (5 mo) and old (23mo) trained animals (P less than 0.05). It was found that the ratio of fast to slow MHC was significantly higher (P less than 0.005) in the crural compared with costal diaphragm region in both age groups. A significant age-related increase in persentage of slow MHC was observed in both diaphragm regions. The relative proportion of slow MHC in either costal or crural region was not changed by exercise training.

Neuromuscular response differences to power vs strength back squat exercise in elite athletes.

PubMed

Brandon, R; Howatson, G; Strachan, F; Hunter, A M

2015-10-01

The study's aim was to establish the neuromuscular responses in elite athletes during and following maximal 'explosive' regular back squat exercise at heavy, moderate, and light loads. Ten elite track and field athletes completed 10 sets of five maximal squat repetitions on three separate days. Knee extension maximal isometric voluntary contraction (MIVC), rate of force development (RFD) and evoked peak twitch force (Pt) assessments were made pre- and post-session. Surface electromyography [root mean square (RMS)] and mechanical measurements were recorded during repetitions. The heavy session resulted in the greatest repetition impulse in comparison to moderate and light sessions (P < 0.001), while the latter showed highest repetition power (P < 0.001). MIVC, RFD, and Pt were significantly reduced post-session (P < 0.01), with greatest reduction observed after the heavy, followed by the moderate and light sessions accordingly. Power significantly reduced during the heavy session only (P < 0.001), and greater increases in RMS occurred during heavy session (P < 0.001), followed by moderate, with no change during light session. In conclusion, this study has shown in elite athletes that the moderate load is optimal for providing a neuromuscular stimulus but with limited fatigue. This type of intervention could be potentially used in the development of both strength and power in elite athletic populations. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Skeletal muscle troponin as a novel biomarker to enhance assessment of the impact of strength training on fall prevention in the older adults.

PubMed

Abreu, Eduardo L; Cheng, An-Lin; Kelly, Patricia J; Chertoff, Keyna; Brotto, Leticia; Griffith, Elizabeth; Kinder, Glenda; Uridge, Tina; Zachow, Rob; Brotto, Marco

2014-01-01

Loss of muscle mass and strength (i.e., sarcopenia) in the older adults is a strong predictor of falls, with subsequent morbidity and inability to execute activities of daily living. Use of biomarkers may enhance assessment of effects of community-based exercise interventions aimed at improving muscle strength. The aim of this study was to investigate the use of troponin as a newly proposed biomarker of skeletal muscle health when determining the outcomes of strength-training programs designed for community-dwelling adults over the age of 65 years. Outcomes of two strength training programs ("Peer Exercise Program Promotes Independence" and "Stay Strong, Stay Healthy") were assessed using physical performance tests designed for senior fitness evaluation, grip strength, and changes in serum levels of skeletal muscle-specific troponin T (sTnT). Improvement in physical performance, including a significant increase in grip strength, was associated with a significant reduction in serum levels of sTnT. Findings from these studies suggest that, when "Peer Exercise Program Promotes Independence" and "Stay Strong, Stay Healthy" are implemented for at least 10 weeks, significant gains in strength are achieved. This strength improvement was associated with a reduction in serum levels of troponin, supporting the use of troponin as a novel biomarker of muscle health in the assessment of strength training programs for the older adults. Reduced sTnT after exercise intervention suggests that skeletal muscles become stronger and less susceptible to damage because of the exercise regimens.

The Response to and Recovery From Maximum-Strength and -Power Training in Elite Track and Field Athletes.

PubMed

Howatson, Glyn; Brandon, Raphael; Hunter, Angus M

2016-04-01

There is a great deal of research on the responses to resistance training; however, information on the responses to strength and power training conducted by elite strength and power athletes is sparse. To establish the acute and 24-h neuromuscular and kinematic responses to Olympic-style barbell strength and power exercise in elite athletes. Ten elite track and field athletes completed a series of 3 back-squat exercises each consisting of 4 × 5 repetitions. These were done as either strength or power sessions on separate days. Surface electromyography (sEMG), bar velocity, and knee angle were monitored throughout these exercises and maximal voluntary contraction (MVC), jump height, central activation ratio (CAR), and lactate were measured pre, post, and 24 h thereafter. Repetition duration, impulse, and total work were greater (P < .01) during strength sessions, with mean power being greater (P < .01) after the power sessions. Lactate increased (P < .01) after strength but not power sessions. sEMG increased (P < .01) across sets for both sessions, with the strength session increasing at a faster rate (P < .01) and with greater activation (P < .01) by the end of the final set. MVC declined (P < .01) after the strength and not the power session, which remained suppressed (P < .05) 24 h later, whereas CAR and jump height remained unchanged. A greater neuromuscular and metabolic demand after the strength and not power session is evident in elite athletes, which impaired maximal-force production for up to 24 h. This is an important consideration for planning concurrent athlete training.

Tapering Practices of Strongman Athletes.

PubMed

Winwood, Paul W; Dudson, Mike K; Wilson, Daniel; Mclaren-Harrison, Justice K H; Redjkins, Vladislav; Pritchard, Hayden J; Keogh, Justin W L

2018-05-01

Winwood, PW, Dudson, MK, Wilson, D, Mclaren-Harrison, JKH, Redjkins, V, Pritchard, HJ, and Keogh, JWL. Tapering practices of strongman athletes. J Strength Cond Res 32(5): 1181-1196, 2018-This study provides the first empirical evidence of how strongman athletes taper for strongman competitions. Strongman athletes (n = 454) (mean ± SD: 33.2 ± 8.0 years, 178.1 ± 10.6 cm, 108.6 ± 27.9 kg, 12.6 ± 8.9 years general resistance training, 5.3 ± 5.0 years strongman implement training) completed a self-reported 4-page internet survey on tapering practices. Analysis by sex (male and female), age (≤30 and >30 years), body mass (≤105 and >105 kg), and competitive standard (local/regional amateur, national amateur and professional) was conducted. Eighty-seven percent (n = 396) of strongman athletes reported that they used a taper. Athletes stated that their typical taper length was 8.6 ± 5.0 days, with the step taper the most commonly performed taper (52%). Training volume decreased during the taper by 45.5 ± 12.9%, and all training ceased 3.9 ± 1.8 days out from competition. Typically, athletes reported that training frequency and training duration stayed the same or decreased and training intensity decreased to around 50% in the last week. Athletes generally stated that tapering was performed to achieve recovery, rest, and peak performance; the deadlift, yoke walk, and stone lifts/work took longer to recover from than other lifts; assistance exercises were reduced or removed in the taper; massage, foam rolling, nutritional changes, and static stretching were strategies used in the taper; and, poor tapering occurred when athletes trained too heavy/hard or had too short a taper. These data will assist strongman athletes and coaches in the optimization of tapering variables leading to more peak performances. Future research could investigate the priming and preactivation strategies strongman athletes use on competition day.

ACTN3 R577X Polymorphism and Neuromuscular Response to Resistance Training

PubMed Central

Gentil, Paulo; Pereira, Rinaldo W.; Leite, Tailce K.M.; Bottaro, Martim

2011-01-01

The R577X polymorphism at the ACTN3 gene has been associated with muscle strength, hypertrophy and athletic status. The X allele, which is associated with the absence of ACTN3 protein is supposed to impair performance of high force/velocity muscle contractions. The purpose of the present study was to investigate the association of the R577X polymorphism with the muscle response to resistance training in young men. One hundred forty one men performed two resistance training sessions per week for 11 weeks. Participants were tested for 1RM bench press, knee extensors peak torque, and knee extensors muscle thickness at baseline and after the training period. Genotyping was conducted using de DdeI restriction enzyme. Genotype distribution was 34.4% for RR, 47% for RX and 18.6% for the XX genotype. According to the results, the R577X polymorphism at the ACTN3 gene is not associated with baseline muscle strength or with the muscle strength response to resistance training. However, only carriers of the R allele showed increases in muscle thickness in response to training. Key points ACTN3 Genotype distribution in the present study was similar to others populations (34.4% for RR, 47% for RX, and 18.6% for the XX). The R577X polymorphism at the ACTN3 gene is not associated with baseline muscle strength or with the muscle strength response to resistance training. It appears that the R allele carriers respond better to muscle thickness gains in response to training. PMID:24149888

ACTN3 R577X Polymorphism and Neuromuscular Response to Resistance Training.

PubMed

Gentil, Paulo; Pereira, Rinaldo W; Leite, Tailce K M; Bottaro, Martim

2011-01-01

The R577X polymorphism at the ACTN3 gene has been associated with muscle strength, hypertrophy and athletic status. The X allele, which is associated with the absence of ACTN3 protein is supposed to impair performance of high force/velocity muscle contractions. The purpose of the present study was to investigate the association of the R577X polymorphism with the muscle response to resistance training in young men. One hundred forty one men performed two resistance training sessions per week for 11 weeks. Participants were tested for 1RM bench press, knee extensors peak torque, and knee extensors muscle thickness at baseline and after the training period. Genotyping was conducted using de DdeI restriction enzyme. Genotype distribution was 34.4% for RR, 47% for RX and 18.6% for the XX genotype. According to the results, the R577X polymorphism at the ACTN3 gene is not associated with baseline muscle strength or with the muscle strength response to resistance training. However, only carriers of the R allele showed increases in muscle thickness in response to training. Key pointsACTN3 Genotype distribution in the present study was similar to others populations (34.4% for RR, 47% for RX, and 18.6% for the XX).The R577X polymorphism at the ACTN3 gene is not associated with baseline muscle strength or with the muscle strength response to resistance training.It appears that the R allele carriers respond better to muscle thickness gains in response to training.

Muscle strength and golf performance: a critical review.

PubMed

Torres-Ronda, Lorena; Sánchez-Medina, Luis; González-Badillo, Juan J

2011-01-01

Golf has become an increasingly popular sport and a growing body of research trying to identify its main physical requirements is being published. The aim of this review was twofold: first, to examine the existing scientific literature regarding strength training and golf in healthy, non-injured, subjects; and second, to reach conclusions that could provide information on how to design more effective strength training programs to improve golf performance as well as directions for future research. Studies which analyzed the relationship between muscle strength, swing performance variables (club head speed, driving distance, ball speed) and skill (handicap, score) were reviewed. Changes in swing performance following different strength training programs were also investigated. Finally, a critical analysis about the methodologies used was carried out. The results of the reviewed studies seem to indicate that: 1) a positive relationship exists between handicap and swing performance (even though few studies have investigated this issue); 2) there is a positive correlation between skill (handicap and/or score) and muscle strength; and 3) there is a relationship between driving distance, swing speed, ball speed and muscle strength. Results suggest that training leg-hip and trunk power as well as grip strength is especially relevant for golf performance improvement. Studies that analyzed variations in swing performance following resistance-only training programs are scarce, thus it is difficult to prove whether the observed improvements are attributable to changes in strength levels. Many of the studies reviewed presented some methodological errors in their design and not all strength assessment protocols seemed appropriate. Further studies should determine muscle strength needs in relation to final swing performance, using well designed experiments and strict isoinertial assessment protocols which adequately relate to specific golf motion, age and skill level. More studies with elite participants, either professional or amateur, would be especially desirable. Key pointsPOSITIVE CORRELATIONS EXIST BETWEEN: 1) handicap and swing performance variables; 2) muscle strength and skill (handicap and/or golf score); and 3) driving dis-tance, swing speed, ball speed and muscle strength.Leg-hip, trunk power and grip strength seem espe-cially relevant for golf performance improvement.Further research should determine muscle strength needs in relation to final swing performance, using well designed experiments and strict assessment pro-tocols which adequately relate to specific golf mo-tion, age and skill level.

Muscle Strength And Golf Performance: A Critical Review

PubMed Central

Torres-Ronda, Lorena; Sánchez-Medina, Luis; González-Badillo, Juan J.

2011-01-01

Golf has become an increasingly popular sport and a growing body of research trying to identify its main physical requirements is being published. The aim of this review was twofold: first, to examine the existing scientific literature regarding strength training and golf in healthy, non-injured, subjects; and second, to reach conclusions that could provide information on how to design more effective strength training programs to improve golf performance as well as directions for future research. Studies which analyzed the relationship between muscle strength, swing performance variables (club head speed, driving distance, ball speed) and skill (handicap, score) were reviewed. Changes in swing performance following different strength training programs were also investigated. Finally, a critical analysis about the methodologies used was carried out. The results of the reviewed studies seem to indicate that: 1) a positive relationship exists between handicap and swing performance (even though few studies have investigated this issue); 2) there is a positive correlation between skill (handicap and/or score) and muscle strength; and 3) there is a relationship between driving distance, swing speed, ball speed and muscle strength. Results suggest that training leg-hip and trunk power as well as grip strength is especially relevant for golf performance improvement. Studies that analyzed variations in swing performance following resistance-only training programs are scarce, thus it is difficult to prove whether the observed improvements are attributable to changes in strength levels. Many of the studies reviewed presented some methodological errors in their design and not all strength assessment protocols seemed appropriate. Further studies should determine muscle strength needs in relation to final swing performance, using well designed experiments and strict isoinertial assessment protocols which adequately relate to specific golf motion, age and skill level. More studies with elite participants, either professional or amateur, would be especially desirable. Key points Positive correlations exist between: 1) handicap and swing performance variables; 2) muscle strength and skill (handicap and/or golf score); and 3) driving dis-tance, swing speed, ball speed and muscle strength. Leg-hip, trunk power and grip strength seem espe-cially relevant for golf performance improvement. Further research should determine muscle strength needs in relation to final swing performance, using well designed experiments and strict assessment pro-tocols which adequately relate to specific golf mo-tion, age and skill level. PMID:24149290

Exploring the Relationship between Endurance and Strength Training in Power Sports

ERIC Educational Resources Information Center

Rohleva, Mariana

2017-01-01

The purpose of this research work is to track down the level of relation between strength and endurance in training exercises of handball athletes. The most successful ratio has been established during work with two groups of 10 players each, all of whom are university students. They were trained, respectively, according to the general training…

The Effect of an Educational Program on Strength-Training Adherence in Older Adults

ERIC Educational Resources Information Center

Papadopoulos, Charilaos; Jager, Johnna M.

2016-01-01

The purpose of this study was to compare the effects of a strength-training program combined with an educational intervention on resistance-training knowledge, adherence, psychological parameters, and functionality in older individuals residing in assisted living facilities. Twenty-four (mean age: 83.8 ± 8.0 years) participants were divided into…

Shank Muscle Strength Training Changes Foot Behaviour during a Sudden Ankle Supination

PubMed Central

Hagen, Marco; Lescher, Stephanie; Gerhardt, Andreas; Lahner, Matthias; Felber, Stephan; Hennig, Ewald M.

2015-01-01

Background The peroneal muscles are the most effective lateral stabilisers whose tension braces the ankle joint complex against excessive supination. The purpose of this study was to identify the morphological and biomechanical effects of two machine-based shank muscle training methods. Methods Twenty-two healthy male recreationally active sports students performed ten weeks of single-set high resistance strength training with 3 training sessions per week. The subjects conducted subtalar pronator/supinator muscle training (ST) with the right leg by using a custom-made apparatus; the left foot muscles were exercised with machine-based talocrural plantar and dorsiflexor training (TT). Muscle strength (MVIC), muscle volume and foot biomechanics (rearfoot motion, ground reaction forces, muscle reaction times) during a sudden ankle supination were recorded before and after the intervention. Results Compared to TT, ST resulted in significantly higher pronator (14% vs. 8%, P<0.01) and supinator MVIC (25% vs. 12%, P<0.01). During sudden foot inversions, both ST and TT resulted in reduced supination velocity (-12%; P<0.01). The muscle reaction onset time was faster after the training in peroneus longus (PL) (P<0.01). Muscle volume of PL (P<0.01) and TA (P<0.01) increased significantly after both ST and TT. Conclusion After both ST and TT, the ankle joint complex is mechanically more stabilised against sudden supinations due to the muscle volume increase of PL and TA. As the reduced supination velocities indicate, the strength training effects are already present during free-fall. According to a sudden ankle supination in standing position, both machine-based dorsiflexor and pronator strength training is recommended for enhancing the mechanical stability of the ankle. PMID:26110847

Effect of low-intensity resistance training with heat stress on the HSP72, anabolic hormones, muscle size, and strength in elderly women.

PubMed

Yoon, Sung Jin; Lee, Moon Jin; Lee, Hyo Min; Lee, Jin Seok

2017-10-01

Several recent studies have reported that heat stress stimulates the activation of heat shock protein 72 (HSP72), leading to an increase in muscle synthesis. Some studies suggested that low-intensity resistance training combined with heat stress could improve muscle size and strength. This study aimed to identify the effect of low-intensity resistance training with heat stress over 12 weeks on the HSP72, anabolic hormones, muscle size, and strength in elderly women. The subjects were physically healthy women of 65-75 years, who were randomly assigned to one of three groups: a low-intensity resistance training with heating sheet group (HRT group, n = 8), a moderate-intensity resistance training (RT group, n = 6), and a heating sheet group (HEAT group, n = 7). Computed tomography scans, 1-repetition maximum (1RM), and blood samples were taken pre- and post-training. The HSP72 did not vary significantly between the different groups and times. The IGF-1 and 1RM had significantly increased in all three groups after the training (respectively, p < 0.05). Moreover, the cross-sectional area (CSA) of the quadriceps showed a significantly greater increase in the HRT group than in the HEAT group (p < 0.05). We found that low-intensity training with heat stress stimulated the anabolic hormones of elderly women, improving their muscle strength and hypertrophy. We believe that low-intensity training with heat stress is an effective way to prevent muscle atrophy and to improve muscle strength in elderly women.

The Effects of a 6-Week Strength Training on Critical Velocity, Anaerobic Running Distance, 30-M Sprint and Yo-Yo Intermittent Running Test Performances in Male Soccer Players.

PubMed

Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando

2016-01-01

The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer.

The Effects of a 6-Week Strength Training on Critical Velocity, Anaerobic Running Distance, 30-M Sprint and Yo-Yo Intermittent Running Test Performances in Male Soccer Players

PubMed Central

Karsten, Bettina; Larumbe-Zabala, Eneko; Kandemir, Gokhan; Hazir, Tahir; Klose, Andreas; Naclerio, Fernando

2016-01-01

The objectives of this study were to examine the effects of a moderate intensity strength training on changes in critical velocity (CV), anaerobic running distance (D'), sprint performance and Yo-Yo intermittent running test (Yo-Yo IR1) performances. Methods: two recreational soccer teams were divided in a soccer training only group (SO; n = 13) and a strength and soccer training group (ST; n = 13). Both groups were tested for values of CV, D', Yo-Yo IR1 distance and 30-m sprint time on two separate occasions (pre and post intervention). The ST group performed a concurrent 6-week upper and lower body strength and soccer training, whilst the SO group performed a soccer only training. Results: after the re-test of all variables, the ST demonstrated significant improvements for both, YoYo IR1 distance (p = 0.002) and CV values (p<0.001) with no significant changes in the SO group. 30-m sprint performance were slightly improved in the ST group with significantly decreased performance times identified in the SO group (p<0.001). Values for D' were slightly reduced in both groups (ST -44.5 m, 95% CI = -90.6 to 1.6; SO -42.6 m, 95% CI = -88.7 to 3.5). Conclusions: combining a 6-week moderate strength training with soccer training significantly improves CV, Yo-Yo IR1 whilst moderately improving 30-m sprint performances in non-previously resistance trained male soccer players. Critical Velocity can be recommended to coaches as an additional valid testing tool in soccer. PMID:27015418

An air brake model for longitudinal train dynamics studies

NASA Astrophysics Data System (ADS)

Wei, Wei; Hu, Yang; Wu, Qing; Zhao, Xubao; Zhang, Jun; Zhang, Yuan

2017-04-01

Experience of heavy haul train operation shows that heavy haul train fatigue fracture of coupler and its related components, even the accidents are caused by excessive coupler force. The most economical and effective method to study on train longitudinal impulse by reducing the coupler force is simulation method. The characteristics of train air brake system is an important excitation source for the study of longitudinal impulse. It is very difficult to obtain the braking characteristic by the test method, a better way to get the input parameters of the excitation source in the train longitudinal dynamics is modelling the train air brake system. In this paper, the air brake system model of integrated system of air brake and longitudinal dynamics is introduced. This introduce is focus on the locomotive automatic brake valve and vehicle distribution valve model, and the comparative analysis of the simulation and test results of the braking system is given. It is proved that the model can predict the characteristics of train braking system. This method provides a good solution for the excitation source of longitudinal dynamic analysis system.

Effects of a Resistance Training Intervention on Strength, Power, and Performance in Adolescent Dancers.

PubMed

Dowse, Rebecca A; McGuigan, Mike R; Harrison, Craig

2017-11-01

Dowse, RA, McGuigan, MR, and Harrison, C. Effects of a resistance training intervention on strength, power, and performance in adolescent dancers. J Strength Cond Res XX(X): 000-000, 2017-The aim of this study was to determine whether a 9-week resistance training program could have a significant effect on maximum lower-body strength and power, dynamic balance, and dance performance in adolescent dancers. Twelve competitive adolescent female dancers trained in jazz, ballet, and contemporary were recruited from local dance schools and assigned to a resistance training group (dance experience 9.2 ± 2.4 years; age 14.2 ± 1.9 years; height 155.6 ± 9.1 cm; and mass 48.9 ± 13.8 kg). Anthropometry (height, seated height, mass, and skinfolds), subjective dancing performance, dynamic balance (eyes open [EO] and eyes closed), maximum lower-body strength (isometric midthigh pull), and power (vertical countermovement jump, squat jump, and single-leg countermovement jump) were assessed before and after the 9-week intervention period. Posttesting identified a significant improvement EO overall stability (p = 0.003; effect size [ES] = 0.88), EO anterior-posterior stability (p = 0.003; ES = 0.92), peak force (p < 0.001; ES = 0.61), peak power (p = 0.021; ES = 0.22), and subjective dancing performance (p = 0.008; ES = 0.76). These results were accompanied by a trivial but significant change in mass (p = 0.023; ES = 0.09) that was attributed to growth and no significant change in body fat or the sum of skinfolds. This study demonstrated that resistance training can have a significant effect on dynamic balance, maximum lower-body strength, and power without adversely affecting artistic or esthetic components. The results suggest that incorporating resistance training may enhance strength and power adaptations and manage growth-related changes in adolescent dancers.

Strength Training Decreases Inflammation and Increases Cognition and Physical Fitness in Older Women with Cognitive Impairment.

PubMed

Chupel, Matheus U; Direito, Fábio; Furtado, Guilherme E; Minuzzi, Luciéle G; Pedrosa, Filipa M; Colado, Juan C; Ferreira, José P; Filaire, Edith; Teixeira, Ana M

2017-01-01

Introduction: Cognitive impairment that affects older adults is commonly associated with an inflammatory imbalance, resulting in decreased physical fitness. Exercise has been pointed to mitigate immunosenescence and cognitive impairment associated with aging, while increase in physical fitness. However, few studies explored the relationship between changes in cytokine concentration and improvement on cognition due to elastic band strength training. The aim of this study was to investigate the effects of strength training on pro-and anti-inflammatory cytokines, hematological markers and physical fitness of older women with cognitive impairment. Methods: Thirty-three women (82.7 ± 5.7 years old) participated in the study and were divided in two groups: strength exercise training group (ST; n = 16) and Control Group (CG; n = 17) and were evaluated before and after 28 weeks of the exercise program. The CG did not undergo any type of exercise programs. Data for IL-10, TNF-α, IFN-γ, C-Reactive Protein (CRP), white blood counts (WBC), red blood counts (RBC), Mini Mental State Examination (MMSE) and physical fitness tests were analyzed in both moments. Results: IL-10 increased in the ST group without changes in CG. TNF-α and CRP increased in the control group while no changes were observed for IFN-γ in both groups. Strength training decreased leukocyte and lymphocyte counts and increase hemoglobin, mean cell volume and mean cell hemoglobin concentration. The MMSE score increased in strength training group but remained unchanged in the control group. A correlation between the variation of granulocyte counts and the MMSE scores was also observed within the total sample. An improvement in physical fitness was observed with strength training. Conclusion: Resistance exercise promoted better anti-inflammatory balance and physical performance simultaneously with an increase in cognitive profile in older women with cognitive impairment.

Lower limb strength in professional soccer players: profile, asymmetry, and training age.

PubMed

Fousekis, Konstantinos; Tsepis, Elias; Vagenas, George

2010-01-01

Kicking and cutting skills in soccer are clearly unilateral, require asymmetrical motor patterns and lead to the development of asymmetrical adaptations in the musculoskeletal function of the lower limbs. Assuming that these adaptations constitute a chronicity-dependent process, this study examined the effects of professional training age (PTA) on the composite strength profile of the knee and ankle joint in soccer players. One hundred soccer players (n=100) with short (5-7 years), intermediate (8-10 years) and long (>11 years) PTA were tested bilaterally for isokinetic concentric and eccentric strength of the knee and ankle muscles. Knee flexion-extension was tested concentrically at 60°, 180° and 300 °/sec and eccentrically at 60° and 180 °/sec. Ankle dorsal and plantar flexions were tested at 60 °/sec for both the concentric and eccentric mode of action. Bilaterally averaged muscle strength [(R+L)/2] increased significantly from short training age to intermediate and stabilized afterwards. These strength adaptations were mainly observed at the concentric function of knee extensors at 60°/sec (p = 0. 023), knee flexors at 60°/sec (p = 0.042) and 180°/sec (p = 0.036), and ankle plantar flexors at 60o/sec (p = 0.044). A linear trend of increase in isokinetic strength with PTA level was observed for the eccentric strength of knee flexors at 60°/sec (p = 0.02) and 180°/sec (p = 0.03). Directional (R/L) asymmetries decreased with PTA, with this being mainly expressed in the concentric function of knee flexors at 180°/sec (p = 0.04) and at 300 °/sec (p = 0.03). These findings confirm the hypothesis of asymmetry in the strength adaptations that take place at the knee and ankle joint of soccer players mainly along with short and intermediate PTA. Players with a longer PTA seem to adopt a more balanced use of their lower extremities to cope with previously developed musculoskeletal asymmetries and possibly reduce injury risk. This has certain implications regarding proper training and injury prevention in relation to professional experience in soccer. Key pointsMuscle strength increased from the low (5-7 years) to the intermediate professional training age (8-10 years) and stabilized thereafter.Soccer practicing and competition at the professional level induces critical strength adaptations (asymmetries) regarding the function of the knee and ankle musculature.Soccer players with long professional training age showed a tendency for lower isokinetic strength asymmetries than players with intermediate and short professional training age.

Effects of plyometric training volume and training surface on explosive strength.

PubMed

Ramírez-Campillo, Rodrigo; Andrade, David C; Izquierdo, Mikel

2013-10-01

The purpose of this study is to examine the effects of different volume and training surfaces during a short-term plyometric training program on neuromuscular performance. Twenty-nine subjects were randomly assigned to 4 groups: control group (CG, n = 5), moderate volume group (MVG, n = 9, 780 jumps), moderate volume hard surface group (MVGHS, n = 8, 780 jumps), and high volume group (HVG, n = 7, 1,560 jumps). A series of tests were performed by the subjects before and after 7 weeks of plyometric training. These tests were measurement of maximum strength (5 maximum repetitions [5RMs]), drop jumps (DJs) of varying heights (20, 40, and 60 cm), squat and countermovement jumps (SJ and CMJ, respectively), timed 20-m sprint, agility, body weight, and height. The results of the present study suggest that high training volume leads to a significant increase in explosive performance that requires fast stretch-shortening cycle (SSC) actions (such as DJ and sprint) in comparison to what is observed after a moderate training volume regimen. Second, when plyometric training is performed on a hard training surface (high-impact reaction force), a moderate training volume induces optimal stimulus to increase explosive performance requiring fast SSC actions (e.g., DJ), maximal dynamic strength enhancement, and higher training efficiency. Thus, a finding of interest in the study was that after 7 weeks of plyometric training, performance enhancement in maximal strength and in actions requiring fast SSC (such as DJ and sprint) were dependent on the volume of training and the surface on which it was performed. This must be taken into account when using plyometric training on different surfaces.

Hyperandrogenism Enhances Muscle Strength After Progressive Resistance Training, Independent of Body Composition, in Women With Polycystic Ovary Syndrome.

PubMed

Kogure, Gislaine S; Silva, Rafael C; Miranda-Furtado, Cristiana L; Ribeiro, Victor B; Pedroso, Daiana C C; Melo, Anderson S; Ferriani, Rui A; Reis, Rosana Maria Dos

2018-06-20

Kogure, GS, Silva, RC, Miranda-Furtado, CL, Ribeiro, VB, Pedroso, DCC, Melo, AS, Ferriani, RA, and Reis, RMd. Hyperandrogenism enhances muscle strength after progressive resistance training, independent of body composition, in women with polycystic ovary syndrome. J Strength Cond Res XX(X): 000-000, 2018-The effects of resistance exercise on muscle strength, body composition, and increase in cross-sectional area of skeletal muscle (hypertrophy) were evaluated in women with polycystic ovary syndrome (PCOS). This case-control study included 45 PCOS and 52 non-PCOS women, with age between 18-37 years and body mass index of 18-39.9 kg·m. Subjects performed a program of progressive resistance training (PRT), 3 times per week for 4 months. Biochemical characteristics were measured before and after PRT. Muscle strength evaluated by 1 maximum repetition test and body composition and hypertrophy indicator, evaluated by anthropometry, were measured at baseline, at 8 weeks, and at 16 weeks after PRT. Progressive resistance training produced an increase in maximum strength (bench press, p = 0.04; leg extension, p = 0.04) in the PCOS group; however, no changes were observed in body composition between groups. Concentration of testosterone decreased in both PCOS and non-PCOS groups (p < 0.01, both) after PRT, as well as glycemia (PCOS, p = 0.01; non-PCOS, p = 0.02) and body fat percentage (p < 0.01, both). An increase in hypertrophy indicators, lean body mass (LBM), and maximum strength on all exercises was observed in both PCOS and non-PCOS groups (p < 0.01). This training protocol promoted increases in muscle strength in PCOS women, and improved hyperandrogenism and body composition by decreasing body fat and increasing LBM and muscle strength in both PCOS and non-PCOS groups. Therefore, it is suggested that resistance exercise programs could promote health and fitness in women of reproductive age, especially functional capacity of strength those with PCOS.

Strength performance in youth: trainability of adolescents and children in the back and front squats.

PubMed

Keiner, Michael; Sander, Andre; Wirth, Klaus; Caruso, Oliver; Immesberger, Peter; Zawieja, Martin

2013-02-01

A basic question for many athletic coaches pertains to the maximum attainable strength level for youth athletes. The aim of this investigation was to establish reference values for the strength performance in the front and back squats in youth athletes. The strength performance in front and back squats of 141 elite youth soccer players was tested by a 1 repetition maximum (1RM) and 1RM related to bodyweight (SREL). The subjects aged between 11 and 19 years and were divided into 2 groups and 4 subgroups (A = younger than 19 years, B = younger than 17 years, C = younger than 15 years, and D = younger than 13 years). For approximately 2 years, one group (control group [CG]) only participated in routine soccer training and the other group (strength training group [STG]) participated in an additional strength training program along with the routine soccer training. Additionally, the strength performance in a 5RM in both squat variants of 105 young elite weightlifters (National Weightlifting Organization Baden Württemberg, [BWG]) was examined to show the high level of trainability of children and adolescents and to determine the reference strength values for young athletes. The STG performed in the parallel front squat SREL in the subgroups A 1.7 +/- 0.2, B 1.6 +/- 0.2, C 1.4 +/-0.2 and D 0.9 +/- 0.3. The STG had significantly (p < 0.001) higher strength values in 1RM and SREL than CG. The BWG had higher strength values than STG, but the BWG was not part of the statistical analysis because of the different test protocols (1RM vs. 5RM). Our data show that the SREL in parallel squat for young elite athletes with long-term training experience should be a minimum of 2.0 for 16- to 19-year-olds, 1.5 for 13- to 15-year-olds, and 0.7 for 11- to 12-year-olds.

Success in the TACP Training Program An Objective Method for Selecting Battlefield Airmen

DTIC Science & Technology

2009-12-23

rationale and evaluation of the physical training doctrine. J Strength Cond Res. 2009 Jul;23(4):1353-62. Interventions used to improve retention...week training programs on military physical performance. J Strength Cond Res. 2008 Mar;22(2):524-34. Muza SR. Military applications of hypoxic...1    Success in the TACP Training Program An Objective Method for Selecting Battlefield Airmen FINAL REPORT December 23, 2009

Cross-education of strength and skill: an old idea with applications in the aging nervous system.

PubMed

Barss, Trevor S; Pearcey, Gregory E P; Zehr, E Paul

2016-03-01

Edward Wheeler Scripture's 1894 work out of the Yale Psychological Laboratory has been influential in identifying the nervous system's contribution to the bilateral improvements that are seen with unilateral strength and skill training. Scripture coined the term "cross-education" to describe this improvement in the untrained contralateral limb. While physiological changes accompany aging that may negatively affect the performance of physical tasks, far too much credit has been given to the natural aging process rather than the effects of inactivity. Emerging evidence indicates strength or skill training interventions induce significant neuroplasticity in an aging population. The model of unilateral training provides a unique approach in which to elicit such plasticity. This brief review highlights the innate ability of the nervous system to adapt to unilateral strength and skill training interventions, regardless of age, and provides a novel perspective on the robust plastic ability of the aging nervous system.

Barriers and motivators for strength training among women of color and Caucasian women.

PubMed

O'Dougherty, Maureen; Dallman, Amber; Turcotte, Lucie; Patterson, Joan; Napolitano, Melissa A; Schmitz, Kathryn H

2008-01-01

The present study examined factors associated with adherence to a strength training (ST) intervention in a randomized controlled intervention trial testing whether twice-weekly strength training over 2 years could prevent age-associated increases in body fat in 80 overweight to mildly obese women, aged 25-44 years. Two sets of focus groups (FGs) were conducted with 25 women of color and 24 Caucasian participants, representing 60% of intervention participants. Fifty-five percent of FG participants had low adherence (defined as < or = 80% adherence to twice-weekly gym-based strength training). Demographic data indicated that marital status and childcare responsibilities affected adherence. Participants' perceptions of experiences in the ST intervention did not correspond to adherence levels or vary by race/ethnicity. Major impediments to adherence included competing obligations and related scheduling difficulties; life transitions; and declining or insufficient social motivators.

Effects of gamma oryzanol supplementation on anthropometric measurements & muscular strength in healthy males following chronic resistance training

PubMed Central

Eslami, Saghar; Esa, Norhaizan Mohd; Marandi, Seyed Mohammad; Ghasemi, Gholamali; Eslami, Sepehr

2014-01-01

Background & objectives: Enhanced muscle strength is seen when resistance exercise is combined with the consumption of nutritional supplements. Although there is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans, but its usage as a nutritional supplement for strength is common in athletes. The aim of this study was to determine the effects of gamma oryzanol supplementation during 9-week resistance training on muscular strength and anthropometric measurements of young healthy males. Methods: In this double-blind clinical trial, changes of anthropometric measurements and muscular strength were studied after chronic resistance exercise and gamma oryzanol supplementation in 30 healthy volunteers (16 in supplement and 14 in placebo). Each day, gamma oryzanol supplement (600 mg) and placebo (the same amount of lactose) were consumed after training. The participants exercised with 80 per cent 1-Repetition Maximum (1-RM), for one hour and four days/week. Anthropometric measurements and subjects’ 1-RM for muscular strength were determined at the commencement and end of the 9-week study. Results: There was no significant difference between the baseline characteristics and target variables at baseline between the two groups. After gamma oryzanol supplementation, there was no significant difference in the means of anthropometric and skin fold measurements between the supplement and placebo groups. However, there were significant differences between the supplement and placebo groups for 1-RM of bench press and leg curl, which showed that gamma oryzanol improved muscle strength following resistance training. Interpretation & conclusions: Our findings indicated that 600 mg/day gamma oryzanol supplementation during the 9-week resistance training did not change anthropometric and body measurements, but it increased muscular strength in young healthy males. Further, studies need to be done in trained athletes, women, and in patients who suffer from muscular fatigue. PMID:25109720

Comparison of the effects of an eight-week push-up program using stable versus unstable surfaces.

PubMed

Chulvi-Medrano, Iván; Martínez-Ballester, Esteban; Masiá-Tortosa, Laura

2012-12-01

Recently, the trend among physical training and rehabilitation professionals is the use of resistance exercise on unstable equipment in order to increase the effort of the agonist and stabilizing muscles. It is unknown if performing exercises on unstable surfaces provides a greater training stimulus as compared to training on a stable training surface. Therefore, the purpose of this research was to compare the effect that push-up training on stable and unstable surfaces had on strength performance in healthy young men. Thirty subjects with experience in resistance training participated in push-up training two days per week for eight weeks on one of three different surfaces: the floor (Tp), the T-Bow® (TBp) or the BOSU® (Bp). Strength, as measured by one repetition maximum (1-RM) and muscle endurance, as measured by number of pushups performed did not improve significantly (p>0.05) for any of the intervention groups. The addition of unstable surfaces in push-up training does not provide greater improvement in muscular strength and endurance than push up training performed on a stable surface in young men. 3b.

Pilates training improves 5-km run performance by changing metabolic cost and muscle activity in trained runners

PubMed Central

Finatto, Paula; Silva, Edson Soares Da; Okamura, Alexandre B.; Almada, Bruna P.; Oliveira, Henrique B.

2018-01-01

Purpose Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet) and an improvement in running performance is feasible with strength training of the postural and trunk muscles. Methods Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16) or the Pilates group (PG, n = 16). Results Confirming our hypothesis, a significant improvement (p<0.05) was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min) compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min). Similarly, the PG (4.33±0.07 J.kg-1.m-1) had better responses than the CG (4.71±0.11 J.kg-1.m-1) during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG. Conclusions Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners. PMID:29561907

Pilates training improves 5-km run performance by changing metabolic cost and muscle activity in trained runners.

PubMed

Finatto, Paula; Silva, Edson Soares Da; Okamura, Alexandre B; Almada, Bruna P; Oliveira, Henrique B; Peyré-Tartaruga, Leonardo A

2018-01-01

Strength training improves distance running economy and performance. This finding is based predominantly on maximal and explosive strength programmes applied to locomotor muscles, particularly on the lower limbs. It is not certain whether a minimization of metabolic cost (Cmet) and an improvement in running performance is feasible with strength training of the postural and trunk muscles. Using kinematic, neuromuscular and metabolic measurements of running at two different speeds before and after a 12-week Pilates training programme, we tested the hypothesis that core training might improve the running Cmet and performance of trained runners. Thirty-two individuals were randomly assigned to the control group (CG, n = 16) or the Pilates group (PG, n = 16). Confirming our hypothesis, a significant improvement (p<0.05) was observed for running performance in the PG (pre: 25.65±0.4 min; post: 23.23±0.4 min) compared to the CG (pre: 25.33±0.58 min; post: 24.61±0.52 min). Similarly, the PG (4.33±0.07 J.kg-1.m-1) had better responses than the CG (4.71±0.11 J.kg-1.m-1) during post-training for Cmet. These findings were accompanied by decreased electromyographic activity of the postural muscles at submaximal running intensities in the PG. Overall, these results provide a rationale for selecting strength training strategies that target adaptations on specific postural and locomotor muscles for trained distance runners.

SORPTION OF CU AND ZN TO KAOLINITE AND IRON OXIDE: EFFECTS OF HUMIC ACID AND IONIC STRENGTH AND IMPLICATIONS FOR STORMWATER RUNOFF

EPA Science Inventory

Heavy metals are common pollutants in wet weather flows and urban waterways. Changes in ionic strength, whether from mixing with saline waters, road salt, or from the large osmotic adjustment needed for the Microtox toxicity assay, affect the aqueous chemistry of stormwater runof...

Optimization Of Fluoride Glass Fiber Drawing With Respect To Mechanical Strength

NASA Astrophysics Data System (ADS)

Schneider, H. W.; Schoberth, A.; Staudt, A.; Gerndt, Ch.

1987-08-01

Heavy metal fluoride fibers have attracted considerable attention recently as lightguides for infrared optical devices. Besides the optical loss mechanical performance of the fiber is of major interest. At present fiber strength suffers from surface crystallization prior to or during fiber drawing. We developed an etching method for the preparation of preforms with clean surface. Drawing these preforms under optimized conditions in a dry atmosphere results in fibers with improved strength. So far, mean value of 400 N/mm2 tensile strength have been achieved. Maximum values of 800 N/mm2 measured on etched fibers indicate an even higher strength potential for the material itself.

The Effects of Individualized Resistance Strength Programs on Knee Muscular Imbalances in Junior Elite Soccer Players

PubMed Central

Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej

2015-01-01

The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p < 0.05)). There were statistically significant changes in RTEG (p < 0.05) related to PT for the hamstrings in both legs, which in turn resulted in an increase in the conventional hamstring/quadriceps ratio (H/Q). It is interesting that the statistically significant (p < 0.05) changes were noted only for the dominant leg. No statistically significant changes in bilateral differences (BD) were noted in either group. These results indicate that individualized resistance training programs could provide additional benefits to traditional strength training protocols to improve muscular imbalances in post-adolescent soccer players. PMID:26630271

Effects of Endurance and Endurance-strength Exercise on Renal Function in Abdominally Obese Women with Renal Hyperfiltration: A Prospective Randomized Trial.

PubMed

Szulińska, Monika; Skrypnik, Damian; Ratajczak, Marzena; Karolkiewicz, Joanna; Madry, Edyta; Musialik, Katarzyna; Walkowiak, Jaroslaw; Jakubowski, Hieronim; Bogdański, Pawel

2016-10-01

Obesity is associated with kidney defects. Physical activity is a key element in the treatment of obesity. The aim of this study was to compare the effect of endurance and endurance-strength training on kidney function in abdominally obese women. Forty-four abdominally obese women were randomized to endurance training or endurance-strength training, three times a week for 3 months. Before and after the intervention, kidney function was assessed by measuring blood creatinine, urine creatinine, and urine albumin levels, and the albumin-to-creatinine ratio and glomerular filtration rate (GFR) were calculated. Renal hyperperfusion was present in both groups before the study. Following both types of physical activity, similar modifications of the investigated parameters were observed, but with no significant between-group differences. Both courses of training led to a significant increase in blood creatinine and a subsequent decrease in the GFR. A significant increase in urine creatinine and album levels, though not exceeding the range for microalbuminuria, was not accompanied by any difference in the albumin-to-creatinine ratio after endurance-strength training alone. Three months of either endurance or endurance-strength training has a favorable and comparable effect on renal function in abdominally obese women with renal hyperfiltration. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Effects of nine weeks isokinetic training on power, golf kinematics, and driver performance in pre-elite golfers.

PubMed

Parker, James; Lagerhem, Charlie; Hellström, John; Olsson, M Charlotte

2017-01-01

It has previously been shown that isotonic strength training can improve driver performance among golfers, though few studies have investigated effects of strength training on swing kinematics together with driver performance. In this study we investigated whether isokinetic rotational training could improve driver performance and swing kinematic variables amongst elite golfers. Twenty competitive pre-elite golfers (handicap better than -3.0), 13 men and 7 women, were split into two groups, one group received the isokinetic power training (IK) alongside their normal isotonic pre-season strength-training and the other group continued with their normal isotonic pre-season strength-training regime (IT). The IK group completed 12 sessions of isokinetic power training on a standing rotation exercise (10% body weight at 1 m/s) and barbell squat (25 kg plus 10% body weight at 0.5 m/s). The IT group continued with their normal isotonic pre-season strength-training regime. Participants were tested for rotational power, lower body power, golf swing kinematics, and driver performance before and after a nine-week training period. After the nine-week training period both the IK and the IT groups increased their dominant side rotational force and power (effect sizes between 0.50-0.96) and magnitude based inference indicated that IK had a likely (> 80%) more beneficial increase in dominant side rotational force and power. For swing kinematics, IK had a likely (> 80%) more beneficial improvement in lead arm speed and acceleration compared to the IT group. For driver performance, IK had a possible (65%) beneficial effect on ball speed and likely (78%) beneficial effect on carry distance when compared to IT, whereas neither of the groups improved club head speed. In the present study on pre-elite golfers we found that 9 weeks of isokinetic training increased seated rotational force and power, peak arm speed and arm acceleration, ball speed, and carry distance more compared to isotonic training. Even though isokinetic training did not increase CHS, it did result in greater carry distance.

Effects of High Intensity Interval Training and Strength Training on Metabolic, Cardiovascular and Hormonal Outcomes in Women with Polycystic Ovary Syndrome: A Pilot Study.

PubMed

Almenning, Ida; Rieber-Mohn, Astrid; Lundgren, Kari Margrethe; Shetelig Løvvik, Tone; Garnæs, Kirsti Krohn; Moholdt, Trine

2015-01-01

Polycystic ovary syndrome is a common endocrinopathy in reproductive-age women, and associates with insulin resistance. Exercise is advocated in this disorder, but little knowledge exists on the optimal exercise regimes. We assessed the effects of high intensity interval training and strength training on metabolic, cardiovascular, and hormonal outcomes in women with polycystic ovary syndrome. Three-arm parallel randomized controlled trial. Thirty-one women with polycystic ovary syndrome (age 27.2 ± 5.5 years; body mass index 26.7 ± 6.0 kg/m2) were randomly assigned to high intensity interval training, strength training, or a control group. The exercise groups exercised three times weekly for 10 weeks. The main outcome measure was change in homeostatic assessment of insulin resistance (HOMA-IR). HOMA-IR improved significantly only after high intensity interval training, by -0.83 (95% confidence interval [CI], -1.45, -0.20), equal to 17%, with between-group difference (p = 0.014). After high intensity interval training, high-density lipoprotein cholesterol increased by 0.2 (95% CI, 0.02, 0.5) mmol/L, with between group difference (p = 0.04). Endothelial function, measured as flow-mediated dilatation of the brachial artery, increased significantly after high intensity interval training, by 2.0 (95% CI, 0.1, 4.0) %, between-group difference (p = 0.08). Fat percentage decreased significantly after both exercise regimes, without changes in body weight. After strength training, anti-Müllarian hormone was significantly reduced, by -14.8 (95% CI, -21.2, -8.4) pmol/L, between-group difference (p = 0.04). There were no significant changes in high-sensitivity C-reactive protein, adiponectin or leptin in any group. High intensity interval training for ten weeks improved insulin resistance, without weight loss, in women with polycystic ovary syndrome. Body composition improved significantly after both strength training and high intensity interval training. This pilot study indicates that exercise training can improve the cardiometabolic profile in polycystic ovary syndrome in the absence of weight loss. ClinicalTrial.gov NCT01919281.

Hydrothermal solidification of municipal solid waste incineration bottom ash with slag addition.

PubMed

Jing, Zhenzi; Ran, Xianqiang; Jin, Fangming; Ishida, Emile H

2010-01-01

Hydrothermal solidification of municipal solid waste incineration (MSWI) bottom ash has been carried out under saturated steam pressure (1.56 MPa) at 200 degrees C for up to 24 h by mixing quartz, slaked lime and water-cooled blast furnace slag (WBFS). The strength enhancement for the WBFS addition was best. The strength development was shown to be due mainly to tobermorite formation, and the tobermorite formation densified matrix, thus promoting the strength development. WBFS seemed to have a higher reactivity than the quartz during the initial hydrothermal process, which provided more silica available to harden the solidified specimens. However, a longer curing time (24 h) was favorable to the quartz dissolution for tobermorite formation, which in turn, enhanced the strength for quartz addition. Curing time affected the crystal morphology evolution, and the stubby plate of tobermorite seemed to result in a high strength enhancement in this study. Laboratory leaching tests were conducted to determine the amount of heavy metals dissolved from the final solidified specimens, and the leaching results showed that after hydrothermal processing the heavy metals dissolved from the solidified specimens were reduced effectively. As such, the hydrothermal processing may have a high potential for recycling/reusing MSWI ash on a large scale. 2010 Elsevier Ltd. All rights reserved.

A Field Experimental Design of a Strengths-Based Training to Overcome Academic Procrastination: Short- and Long-Term Effect.

PubMed

Visser, Lennart; Schoonenboom, Judith; Korthagen, Fred A J

2017-01-01

This study reports on the effect of a newly developed 4-week strengths-based training approach to overcome academic procrastination, given to first-year elementary teacher education students ( N = 54). The training was based on a strengths-based approach, in which elements of the cognitive behavioral approach were also used. The purpose of the training was to promote awareness of the personal strengths of students who experience academic procrastination regularly and to teach them how to use their personal strengths in situations in which they usually tend to procrastinate. With a pretest-posttest control group design (two experimental groups: n = 31, control group: n = 23), the effect of the training on academic procrastination was studied after 1, 11, and 24 weeks. Results of a one-way analysis of covariance revealed a significant short-term effect of the training. In the long term (after 11 and 24 weeks), the scores for academic procrastination for the intervention groups remained stable, whereas the scores for academic procrastination for the control group decreased to the same level as those of the intervention groups. The findings of this study suggest that a strengths-based approach can be helpful to students at an early stage of their academic studies to initiate their individual process of dealing with academic procrastination. The findings for the long term show the importance of measuring the outcomes of an intervention not only shortly after the intervention but also in the long term. Further research is needed to find out how the short-term effect can be maintained in the long-term.

Impact of mild versus moderate intensity aerobic walking exercise training on markers of bone metabolism and hand grip strength in moderate hemophilic A patients.

PubMed

Al-Sharif, Fadwa Al-Ghalib; Al-Jiffri, Osama Hussien; El-Kader, Shehab Mahmoud Abd; Ashmawy, Eman Mohamed

2014-03-01

Patients with hemophilia A have low bone density than healthy controls. It is now widely recognized that physical activity and sports are beneficial for patients with hemophilia. To compare the effects of mild and moderate intensity treadmill walking exercises on markers of bone metabolism and hand grip strength in male patients with moderate hemophilia A. Fifty male patients with moderate hemophilia, and age range from 25 to 45 years. The subjects were randomly assigned into 2 equal groups; the first group (A) received moderate intensity aerobic exercise training. The second group (B) received mild intensity aerobic exercise training. There was a 32.1% and 24.8% increase in mean values of serum calcium and hand grip strength respectively and 22.7 % reduction in mean values of parathyroid hormone in moderate exercise training group (A). While there was a 15.1 % and 15 % increase in mean values of Serum Calcium and Hand grip strength respectively and 10.3 % reduction in mean values of parathyroid hormone in mild exercise training group(B). The mean values of serum calcium and hand grip strength were significantly increased, while the mean values of parathyroid hormone were significantly decreased in both groups . There were significant differences between mean levels of the investigated parameters in group (A) and group (B) after treatment. Moderate intensity aerobic exercise training on treadmill is appropriate to improve markers of bone metabolism and hand grip strength in male patients with hemophilia A.

Strength and power determinants of grinding performance in America's Cup sailors.

PubMed

Pearson, Simon N; Hume, Patria A; Cronin, John B; Slyfield, David

2009-09-01

The purpose grinding is a physically demanding component of America's Cup sailing that is important to overall team performance, but little research is available on the determinants of grinding performance. We examined the relationship between various measures of muscular performance and the performance of upper-body grinding. Eleven elite male America's Cup sailors (33.9 +/- 5.5 yr, 97.8 +/- 12.5 kg, 186.0 +/- 7.1 cm) who performed grinding as part of their on-board role with extensive strength training experience participated in this study. Muscular performance testing examined the force, velocity, and power capabilities of the upper-body musculature, with upper-body push (bench press) and pull (bench pull) movements performed across loads of 10-100% of 1 repetition maximum (1RM). Functional grinding performance was examined for both forward and backward grinding and at 2 different resistances (moderate = 48 N x m, heavy = 68 N x m) using a land-based ergometer. Bench press 1RM and maximum force capability were the measures demonstrating the strongest correlation with forward grinding performance (r = 0.88-0.99 and 0.87-0.99, respectively), with the relationship increasing with grinding load. For backward grinding, there was a very strong relationship with bench pull maximum power (r = 0.85-0.98) in addition to 1RM (r = 0.90-0.95) and maximum force (r = 0.87-0.95). It appears that although maximal strength is a crucial muscular performance characteristic for grinding performance in all conditions, for backward grinding, there is the additional need to focus on the development of speed strength/power to maximize performance gains. This information was used by the Emirates Team New Zealand physical conditioner to develop a conditioning intervention to help improve grinding performance.

Short-Term Effects of Different Loading Schemes in Fitness-Related Resistance Training.

PubMed

Eifler, Christoph

2016-07-01

Eifler, C. Short-term effects of different loading schemes in fitness-related resistance training. J Strength Cond Res 30(7): 1880-1889, 2016-The purpose of this investigation was to analyze the short-term effects of different loading schemes in fitness-related resistance training and to identify the most effective loading method for advanced recreational athletes. The investigation was designed as a longitudinal field-test study. Two hundred healthy mature subjects with at least 12 months' experience in resistance training were randomized in 4 samples of 50 subjects each. Gender distribution was homogenous in all samples. Training effects were quantified by 10 repetition maximum (10RM) and 1 repetition maximum (1RM) testing (pre-post-test design). Over a period of 6 weeks, a standardized resistance training protocol with 3 training sessions per week was realized. Testing and training included 8 resistance training exercises in a standardized order. The following loading schemes were randomly matched to each sample: constant load (CL) with constant volume of repetitions, increasing load (IL) with decreasing volume of repetitions, decreasing load (DL) with increasing volume of repetitions, daily changing load (DCL), and volume of repetitions. For all loading schemes, significant strength gains (p < 0.001) could be noted for all resistance training exercises and both dependent variables (10RM, 1RM). In all cases, DCL obtained significantly higher strength gains (p < 0.001) than CL, IL, and DL. There were no significant differences in strength gains between CL, IL, and DL. The present data indicate that resistance training following DCL is more effective for advanced recreational athletes than CL, IL, or DL. Considering that DCL is widely unknown in fitness-related resistance training, the present data indicate, there is potential for improving resistance training in commercial fitness clubs.

Sequencing Effects of Balance and Plyometric Training on Physical Performance in Youth Soccer Athletes.

PubMed

Hammami, Raouf; Granacher, Urs; Makhlouf, Issam; Behm, David G; Chaouachi, Anis

2016-12-01

Hammami, R, Granacher, U, Makhlouf, I, Behm, DG, and Chaouachi, A. Sequencing effects of balance and plyometric training on physical performance in youth soccer athletes. J Strength Cond Res 30(12): 3278-3289, 2016-Balance training may have a preconditioning effect on subsequent power training with youth. There are no studies examining whether the sequencing of balance and plyometric training has additional training benefits. The objective was to examine the effect of sequencing balance and plyometric training on the performance of 12- to 13-year-old athletes. Twenty-four young elite soccer players trained twice per week for 8 weeks either with an initial 4 weeks of balance training followed by 4 weeks of plyometric training (BPT) or 4 weeks of plyometric training proceeded by 4 weeks of balance training (PBT). Testing was conducted pre- and posttraining and included medicine ball throw; horizontal and vertical jumps; reactive strength; leg stiffness; agility; 10-, 20-, and 30-m sprints; Standing Stork balance test; and Y-Balance test. Results indicated that BPT provided significantly greater improvements with reactive strength index, absolute and relative leg stiffness, triple hop test, and a trend for the Y-Balance test (p = 0.054) compared with PBT. Although all other measures had similar changes for both groups, the average relative improvement for the BPT was 22.4% (d = 1.5) vs. 15.0% (d = 1.1) for the PBT. BPT effect sizes were greater with 8 of 13 measures. In conclusion, although either sequence of BPT or PBT improved jumping, hopping, sprint acceleration, and Standing Stork and Y-Balance, BPT initiated greater training improvements in reactive strength index, absolute and relative leg stiffness, triple hop test, and the Y-Balance test. BPT may provide either similar or superior performance enhancements compared with PBT.

Intermittent versus continuous exercise training in chronic heart failure: a meta-analysis.

PubMed

Smart, Neil A; Dieberg, Gudrun; Giallauria, Francesco

2013-06-20

We conducted a meta-analysis of randomized, controlled trials of combined strength and intermittent aerobic training, intermittent aerobic training only and continuous exercise training in heart failure patients. A systematic search was conducted of Medline (Ovid) (1950-September 2011), Embase.com (1974-September 2011), Cochrane Central Register of Controlled Trials and CINAHL (1981-September 19 2011). The search strategy included a mix of MeSH and free text terms for the key concepts heart failure, exercise training, interval training and intermittent exercise training. The included studies contained an aggregate of 446 patients, 212 completed intermittent exercise training, 66 only continuous exercise training, 59 completed combined intermittent and strength training and 109 sedentary controls. Weighted mean difference (MD) in Peak VO2 was 1.04mlkg(-1)min(-1) and (95% C.I.) was 0.42-1.66 (p=0.0009) in intermittent versus continuous exercise training respectively. Weighted mean difference in Peak VO2 was -1.10mlkg(-1)min(-1) (95% C.I.) was -1.83-0.37 p=0.003 for intermittent only versus intermittent and strength (combined) training respectively. In studies reporting VE/VCO2 for intermittent versus control groups, MD was -1.50 [(95% C.I. -2.64, -0.37), p=0.01] and for intermittent versus continuous exercise training MD was -1.35 [(95% C.I. -2.15, -0.55), p=0.001]. Change in peak VO2 was positively correlated with weekly exercise energy expenditure for intermittent exercise groups (r=0.48, p=0.05). Combined strength and intermittent exercise appears superior for peak VO2 changes when compared to intermittent exercise of similar exercise energy expenditure. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

The efficacy of incorporating partial squats in maximal strength training.

PubMed

Bazyler, Caleb D; Sato, Kimitake; Wassinger, Craig A; Lamont, Hugh S; Stone, Michael H

2014-11-01

The purpose of our study was to examine the effects of 2 different training methods on dynamic and isometric measures of maximal strength. Seventeen recreationally trained men (1 repetition maximum [1RM] squat: 146.9 ± 22.4 kg) were assigned to 2 groups: full range of motion (ROM) squat (F) and full ROM with partial ROM squat (FP) for the 7-week training intervention. Repeated measures analysis of variance revealed that there was a statistically significant group-by-time interaction for impulse scaled at 50, 90, and 250 milliseconds at 90° of knee flexion and rate of force development at 200 milliseconds with 120° of knee flexion (p ≤ 0.05). There was also a statistically significant time effect (p ≤ 0.05) for the 1RM squat, 1RM partial squat, isometric squat peak force allometrically scaled (IPFa) 90°, IPFa 120°, and impulse allometrically scaled at 50, 90, 200, and 250 milliseconds at 90° and 120° of knee flexion. Additionally, the FP group achieved statistically larger relative training intensities (%1RM) during the final 3 weeks of training (p ≤ 0.05). There was a trend for FP to improve over F in 1RM squat (+3.1%, d = 0.53 vs. 0.32), 1RM partial squat (+4.7%, d = 0.95 vs. 0.69), IPFa 120° (+5.7%, d = 0.52 vs. 0.12), and impulse scaled at 50, 90, 200, and 250 milliseconds at 90° (+6.3 to 13.2%, d = 0.50-1.01 vs. 0.30-0.57) and 120° (+3.4 to 16.8%, d = 0.45-1.11 vs. 0.08-0.37). These larger effect sizes in the FP group can likely be explained their ability to train at larger relative training intensities during the final 3 weeks of training resulting in superior training adaptations. Our findings suggest that partial ROM squats in conjunction with full ROM squats may be an effective training method for improving maximal strength and early force-time curve characteristics in men with previous strength training experience. Practically, partial squats may be beneficial for strength and power athletes during a strength-speed mesocycle while peaking for competition.

Pelvic floor muscle training increases pelvic floor muscle strength more in post-menopausal women who are not using hormone therapy than in women who are using hormone therapy: a randomised trial.

PubMed

Ignácio Antônio, Flávia; Herbert, Robert D; Bø, Kari; Rosa-E-Silva, Ana Carolina Japur Sá; Lara, Lúcia Alves Silva; Franco, Maira de Menezes; Ferreira, Cristine Homsi Jorge

2018-06-15

Are there differences in the effectiveness of pelvic floor muscle training on pelvic floor muscle strength and urinary incontinence symptoms in postmenopausal women who are and are not using hormone therapy? Randomised, controlled trial with concealed allocation, blinded assessors, and intention-to-treat analysis. Ninety-nine postmenopausal women, 38 of whom were using daily systemic oestrogen/progestogen therapy. The experimental group (n=51) received an intensive supervised pelvic floor muscle training protocol, and the control group (n=48) received no intervention. The randomisation was stratified by hormone therapy use. Change in pelvic floor muscle strength assessed with manometry at 12 weeks. Prevalence and severity of urinary incontinence symptoms were assessed using questionnaires. Eighty-eight women provided data that could be included in the analysis. Pelvic floor muscle training increased pelvic floor muscle strength by 8.0 cmH 2 O (95% CI 3.4 to 12.6) in women not using hormone therapy and by -0.9 cmH 2 0 (95% CI -6.5 to 4.8) in women using hormone therapy (interaction p=0.018). A sensitivity analysis showed that the greater training effect in women who were not using hormone therapy was still apparent if the analysis was conducted on percentage change in strength rather than absolute change in strength. There was also a significantly greater effect of training in women not using hormone therapy on prevalence of urinary incontinence symptoms (ratio of odds ratios=7.4; interaction p=0.028). The difference in effects on severity of urinary incontinence symptoms was not statistically significant (interaction p=0.37). Pelvic floor muscle training increases pelvic floor muscle strength more in women who are not using hormone therapy than in women using hormone therapy. ClinicalTrials.gov NCT02549729. [Ignácio Antônio F, Herbert RD, Bø K, Rosa-e-Silva ACJS, Lara LAS, Franco MdM, Ferreira CHJ (2018) Pelvic floor muscle training increases pelvic floor muscle strength more in post-menopausal women who are not using hormone therapy than in women who are using hormone therapy: a randomised trial. Journal of Physiotherapy XX: XX-XX]. Copyright © 2018 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Lower limb explosive strength capacity in elderly women: effects of resistance training and healthy diet.

PubMed

Edholm, Peter; Strandberg, Emelie; Kadi, Fawzi

2017-07-01

The effects of 24 wk of resistance training combined with a healthy diet on lower limb explosive strength capacity were investigated in a population of healthy elderly women. Participants ( n = 63; 67.5 ± 0.4 yr) were randomized into three groups; resistance training (RT), resistance training and healthy diet (RT-HD), and control (CON). Progressive resistance training was performed at a load of 75-85% one-repetition maximum. A major adjustment in the healthy dietary approach was an n-6/n-3 polyunsaturated fatty acid (PUFA) ratio below 2. Lower limb maximal strength, explosive force capacity during dynamic and isometric movements, whole body lean mass, and physical function were assessed. Whole body lean mass significantly increased by 1.5 ± 0.5% in RT-HD only. Isometric strength performance during knee extension as well as the performance in the five sit-to-stand and single-leg-stance tests increased similarly in RT and RT-HD. Improvements in dynamic peak power and time to reach peak power (i.e shorter time) during knee extension occurred in both RT (+15.7 ± 2.6 and -11.0 ± 3.8%, respectively) and RT-HD (+24.6 ± 2.6 and -20.3 ± 2.7%, respectively); however, changes were significantly larger in RT-HD. Similarly, changes in peak force and rate of force development during squat jump were higher in RT-HD (+58.5 ± 8.4 and +185.4 ± 32.9%, respectively) compared with RT (+35.7 ± 6.9 and +105.4 ± 22.4%, respectively). In conclusion, a healthy diet rich in n-3 PUFA can optimize the effects of resistance training on dynamic explosive strength capacity during isolated lower limb movements and multijoint exercises in healthy elderly women. NEW & NOTEWORTHY Age-related decline in lower limb explosive strength leads to impaired ability to perform daily living tasks. The present randomized controlled trial demonstrates that a healthy diet rich in n-3 polyunsaturated fatty acid (n-3 PUFA) enhances resistance training-induced gains in dynamic explosive strength capacity during isolated lower limb movements and multijoint exercises in healthy elderly women. This supports the use of strategies combining resistance training and dietary changes to mitigate the decline in explosive strength capacity in older adults. Copyright © 2017 the American Physiological Society.

FAST INdiCATE Trial protocol. Clinical efficacy of functional strength training for upper limb motor recovery early after stroke: neural correlates and prognostic indicators.

PubMed

Pomeroy, Valerie M; Ward, Nick S; Johansen-Berg, Heidi; van Vliet, Paulette; Burridge, Jane; Hunter, Susan M; Lemon, Roger N; Rothwell, John; Weir, Christopher J; Wing, Alan; Walker, Andrew A; Kennedy, Niamh; Barton, Garry; Greenwood, Richard J; McConnachie, Alex

2014-02-01

Functional strength training in addition to conventional physical therapy could enhance upper limb recovery early after stroke more than movement performance therapy plus conventional physical therapy. To determine (a) the relative clinical efficacy of conventional physical therapy combined with functional strength training and conventional physical therapy combined with movement performance therapy for upper limb recovery; (b) the neural correlates of response to conventional physical therapy combined with functional strength training and conventional physical therapy combined with movement performance therapy; (c) whether any one or combination of baseline measures predict motor improvement in response to conventional physical therapy combined with functional strength training or conventional physical therapy combined with movement performance therapy. Randomized, controlled, observer-blind trial. The sample will consist of 288 participants with upper limb paresis resulting from a stroke that occurred within the previous 60 days. All will be allocated to conventional physical therapy combined with functional strength training or conventional physical therapy combined with movement performance therapy. Functional strength training and movement performance therapy will be undertaken for up to 1·5 h/day, five-days/week for six-weeks. Measurements will be undertaken before randomization, six-weeks thereafter, and six-months after stroke. Primary efficacy outcome will be the Action Research Arm Test. Explanatory measurements will include voxel-wise estimates of brain activity during hand movement, brain white matter integrity (fractional anisotropy), and brain-muscle connectivity (e.g. latency of motor evoked potentials). The primary clinical efficacy analysis will compare treatment groups using a multilevel normal linear model adjusting for stratification variables and for which therapist administered the treatment. Effect of conventional physical therapy combined with functional strength training versus conventional physical therapy combined with movement performance therapy will be summarized using the adjusted mean difference and 95% confidence interval. To identify the neural correlates of improvement in both groups, we will investigate associations between change from baseline in clinical outcomes and each explanatory measure. To identify baseline measurements that independently predict motor improvement, we will develop a multiple regression model. © 2013 The Authors. International Journal of Stroke published by John Wiley & Sons Ltd on behalf of World Stroke Organization.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, R. Y.; Zhang, S. J.; Bauer, E. D.

We report optical spectroscopy and ultrafast pump-probe measurements on the antiferromagnetic heavy-fermion compound CePt 2 In 7 , a member showing stronger two dimensionality than other compounds in the CeIn 3 -derived heavy-fermion family. Here, we identify clear and typical hybridization spectral structures at low temperature from the two different spectroscopy probes. But, the strength and related energy scale of the hybridization are much weaker and smaller than that in the superconducting compounds CeCoIn 5 and CeIrIn 5 . The features are more similar to observations on the antiferromagnetic compounds CeIn 3 and CeRhIn 5 in the same family. Ourmore » results clearly indicate that the Kondo interaction and hybridizations exist in the antiferromagnetic compounds but with weaker strength.« less

Comparison of heavy metals and uranium removal using adsorbent in soil

NASA Astrophysics Data System (ADS)

Choi, Jaeyoung; Yun, Hunsik

2017-04-01

This study investigates heavy metals (As, Ni, Zn, Cd, and Pb) and uranium removal onto geomaterials (limestone, black shale, and concrete) and biosorbents (Pseudomonas putida and starfish) from waste in soil. Geomaterials or biosorbents with a high capacity for heavy metals and uranium can be obtained and employed of with little cost. For investigating the neutralization capacity, the change in pH, Eh, and EC as a function of time was quantified. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing heavy metals and uranium concentrations. Dead cells adsorbed the largest quantity of all heavy metals than lother sorbents. The adsorption capacity followed the order: U(VI) > Pb > Cd > Ni. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated soil.

Effects of nine weeks of beta-hydroxy-beta- methylbutyrate supplementation on strength and body composition in resistance trained men.

PubMed

Thomson, Jasmine S; Watson, Patricia E; Rowlands, David S

2009-05-01

The dietary supplement beta-hydroxy-beta-methylbutyrate (HMB) is claimed to increase strength, lean body mass, and decrease fat mass when used in conjunction with resistance training. Although there is some support for these claims, the evidence is not conclusive, and it is even less so for resistance trained individuals. Therefore, we aimed to further elucidate the effects of HMB supplementation in trained men. A randomized, double-blind, controlled study design was used to investigate the effects of supplementing 22 resistance trained men with 3 g.d of HMB or corn starch placebo for 9 weeks with resistance training. The effect of HMB on strength was determined using the 1-repetition maximum (1RM) method for the lower body (leg extension) and upper body (bench press, bicep preacher curl) at baseline and after the supplementation period. Body composition was assessed by skinfolds and bioelectrical impedance analysis (BIA). Overall, 9 weeks' HMB supplementation resulted in a clear-cut, trivial increase in combined averaged strength measures of 1.6% (90% confidence limits: +/-4.3%). When considered in isolation, however, leg extension 1RM increased by a substantial 9.1% (90% confidence limits: +/-7.5%), but the effect on upper-body strength was inconclusive (bench press: -1.9 +/- 9.3%; bicep curl: -1.7 +/- 4.7%). Based on BIA estimates, HMB had a decreasing (although inconclusive) influence on fat mass of -9 +/- 14%, but it had a clear, trivial effect on fat-free mass of 0.2 +/- 2.2%. The magnitude of change in body mass was trivial, but the probability of substantial reductions in skinfold thicknesses ranged from negligible to likely. In previously trained men, supplementation of HMB in conjunction with resistance training provides a substantial benefit to lower-body strength, but it has negligible effects on body composition.

Respiratory muscle training increases respiratory muscle strength and reduces respiratory complications after stroke: a systematic review.

PubMed

Menezes, Kênia Kp; Nascimento, Lucas R; Ada, Louise; Polese, Janaine C; Avelino, Patrick R; Teixeira-Salmela, Luci F

2016-07-01

After stroke, does respiratory muscle training increase respiratory muscle strength and/or endurance? Are any benefits carried over to activity and/or participation? Does it reduce respiratory complications? Systematic review of randomised or quasi-randomised trials. Adults with respiratory muscle weakness following stroke. Respiratory muscle training aimed at increasing inspiratory and/or expiratory muscle strength. Five outcomes were of interest: respiratory muscle strength, respiratory muscle endurance, activity, participation and respiratory complications. Five trials involving 263 participants were included. The mean PEDro score was 6.4 (range 3 to 8), showing moderate methodological quality. Random-effects meta-analyses showed that respiratory muscle training increased maximal inspiratory pressure by 7 cmH2O (95% CI 1 to 14) and maximal expiratory pressure by 13 cmH2O (95% CI 1 to 25); it also decreased the risk of respiratory complications (RR 0.38, 95% CI 0.15 to 0.96) compared with no/sham respiratory intervention. Whether these effects carry over to activity and participation remains uncertain. This systematic review provided evidence that respiratory muscle training is effective after stroke. Meta-analyses based on five trials indicated that 30minutes of respiratory muscle training, five times per week, for 5 weeks can be expected to increase respiratory muscle strength in very weak individuals after stroke. In addition, respiratory muscle training is expected to reduce the risk of respiratory complications after stroke. Further studies are warranted to investigate whether the benefits are carried over to activity and participation. PROSPERO (CRD42015020683). [Menezes KKP, Nascimento LR, Ada L, Polese JC, Avelino PR, Teixeira-Salmela LF (2016) Respiratory muscle training increases respiratory muscle strength and reduces respiratory complications after stroke: a systematic review.Journal of Physiotherapy62: 138-144]. Copyright © 2016 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

Effects of 12-week concurrent high-intensity interval strength and endurance training programme on physical performance in healthy older people.

PubMed

García-Pinillos, Felipe; Laredo-Aguilera, José A; Muñoz-Jiménez, Marcos; Latorre-Román, Pedro A

2017-03-13

This study aimed to analyse the effect of 12-week low-volume HIIT-based concurrent training programme on body composition, upper- and lower-body muscle strength, mobility and balance in older adults, as well as to compare it with a low- moderate-intensity continuous training. 90 active older adults were randomly assigned to experimental (EG, n=47), and control (CG, n=43) groups. Body composition and physical functioning were assessed before (pre-test) and after (post-test) a 12-week intervention. A 2-way repeated measures ANOVA was used to test for an interaction between training programme and groups. The time x group interaction revealed no significant between-group differences at pre-test (p≥0.05). The group x time interaction showed significant improvements for the EG in body composition parameters (p<0.05) and physical functioning (muscle strength: p<0.001; mobility: p<0.001; and balance: p<0.05); while the CG remained unchanged (p≥0.05). This HIIT-based concurrent training programme led to greater improvements in body composition, muscle strength, mobility and balance in healthy older people than a regular low- moderate-intensity continuous training, despite the reduction in overall training volume.

Program to study optimal protocol for cardiovascular and muscular efficiency. [physical fitness training for manned space flight

NASA Technical Reports Server (NTRS)

Olree, H. D.

1974-01-01

Training programs necessary for the development of optimal strength during prolonged manned space flight were examined, and exercises performed on the Super Mini Gym Skylab 2 were compared with similar exercises on the Universal Gym and calisthenics. Cardiopulmonary gains were found negligible but all training groups exhibited good gains in strength.

The Influence of Resistance Training Experience on the Between-Day Reliability of Commonly Used Strength Measures in Male Youth Athletes.

PubMed

Weakley, Jonathon J S; Till, Kevin; Darrall-Jones, Joshua; Roe, Gregory A B; Phibbs, Padraic J; Read, Dale B; Jones, Ben L

2017-07-01

Weakley, JJS, Till, K, Darrall-Jones, J, Roe, GAB, Phibbs, PJ, Read, DB, and Jones, BL. The influence of resistance training experience on the between-day reliability of commonly used strength measures in male youth athletes. J Strength Cond Res 31(7): 2005-2010, 2017-The purpose of this study was to determine the between-day reliability of commonly used strength measures in male youth athletes while considering resistance training experience. Data were collected on 25 male athletes over 2 testing sessions, with 72 hours rest between, for the 3 repetition maximum (3RM) front squat, chin-up, and bench press. Subjects were initially categorized by resistance training experience (inexperienced; 6-12 months, experienced; >2 years). The assessment of the between-day reliability (coefficient of variation [CV%]) showed that the front squat (experienced: 2.90%; inexperienced: 1.90%), chin-up (experienced: 1.70%; inexperienced: 1.90%), and bench press (experienced: 4.50%; inexperienced: 2.40%) were all reliable measures of strength in both groups. Comparison between groups for the error of measurement for each exercise showed trivial differences. When both groups were combined, the CV% for the front squat, bench press, and chin-up were 2.50, 1.80, and 3.70%, respectively. This study provides scientists and practitioners with the between-day reliability reference data to determine real and practical changes for strength in male youth athletes with different resistance training experience. Furthermore, this study demonstrates that 3RM front squat, chin-up, and bench press are reliable exercises to quantify strength in male youth athletes.

Effects of 4 Weeks of Explosive-type Strength Training for the Plantar Flexors on the Rate of Torque Development and Postural Stability in Elderly Individuals.

PubMed

Kobayashi, Y; Ueyasu, Y; Yamashita, Y; Akagi, R

2016-06-01

This study aimed to investigate the effect of a 4-week explosive-type strength training program for the plantar flexors on the rate of torque development and postural stability. The participants were 56 elderly men and women divided into training (17 men and 15 women) and control (14 men and 10 women) groups. The participants in the training group underwent explosive-type strength training of the plantar flexors 2 days per week for 4 weeks. Training consisted of 3 sets of 10 repetitions of explosive plantar flexion lasting less than 1 s. The following parameters were determined: muscle volume of the plantar flexors estimated by the muscle thickness and lower leg length, maximal voluntary contraction torque and rate of torque development of plantar flexion, and one-leg standing ability. The training increased the maximal voluntary contraction torque and rate of torque development, but corresponding increases in muscle volume and one-leg standing ability were not found. These results suggest that, for elderly individuals, the 4-week explosive-type strength training of the plantar flexors is effective for increasing the maximal voluntary contraction torque and rate of torque development of plantar flexion but is not effective for improving postural stability. © Georg Thieme Verlag KG Stuttgart · New York.

Haulage Truck Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for haulage truck operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Rotary Drill Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for rotary drill operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Track Dozer Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for track dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Grader Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for grader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Rubber Tire Dozer Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

British Columbia Dept. of Education, Victoria.

This training outline for rubber tire dozer operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Front End Loader Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Savilow, Bill

This training outline for front end loader operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for…

Shovel Operator. Open Pit Mining Job Training Series.

ERIC Educational Resources Information Center

Hartley, Larry

This training outline for shovel operators, one in a series of eight outlines, is designed primarily for company training foremen or supervisors and for trainers to use as an industry-wide guideline for heavy equipment operator training in open pit mining in British Columbia. Intended as a guide for preparation of lesson plans both for classroom…

Effects of Strength Training Combined with Specific Plyometric exercises on body composition, vertical jump height and lower limb strength development in elite male handball players: a case study.

PubMed

Carvalho, Alberto; Mourão, Paulo; Abade, Eduardo

2014-06-28

The purpose of the present study was to identify the effects of a strength training program combined with specific plyometric exercises on body composition, vertical jump (VJ) height and strength development of lower limbs in elite male handball players. A 12-week program with combined strength and specific plyometric exercises was carried out for 7 weeks. Twelve elite male handball players (age: 21.6 ± 1.73) competing in the Portuguese Major League participated in the study. Besides the anthropometric measurements, several standardized jump tests were applied to assess VJ performance together with the strength development of the lower limbs in an isokinetic setting. No significant changes were found in body circumferences and diameters. Body fat content and fat mass decreased by 16.4 and 15.7% respectively, while lean body mass increased by 2.1%. Despite small significance, there was in fact an increase in squat jump (SJ), counter movement jump (CMJ) and 40 consecutive jumps after the training period (6.1, 3.8 and 6.8%, respectively). After the applied protocol, peak torque increased in lower limb extension and flexion in the majority of the movements assessed at 90ºs-1. Consequently, it is possible to conclude that combining general strength-training with plyometric exercises can not only increase lower limb strength and improve VJ performance but also reduce body fat content.

Effects of Strength Training Combined with Specific Plyometric exercises on body composition, vertical jump height and lower limb strength development in elite male handball players: a case study

PubMed Central

Carvalho, Alberto; Mourão, Paulo; Abade, Eduardo

2014-01-01

The purpose of the present study was to identify the effects of a strength training program combined with specific plyometric exercises on body composition, vertical jump (VJ) height and strength development of lower limbs in elite male handball players. A 12-week program with combined strength and specific plyometric exercises was carried out for 7 weeks. Twelve elite male handball players (age: 21.6 ± 1.73) competing in the Portuguese Major League participated in the study. Besides the anthropometric measurements, several standardized jump tests were applied to assess VJ performance together with the strength development of the lower limbs in an isokinetic setting. No significant changes were found in body circumferences and diameters. Body fat content and fat mass decreased by 16.4 and 15.7% respectively, while lean body mass increased by 2.1%. Despite small significance, there was in fact an increase in squat jump (SJ), counter movement jump (CMJ) and 40 consecutive jumps after the training period (6.1, 3.8 and 6.8%, respectively). After the applied protocol, peak torque increased in lower limb extension and flexion in the majority of the movements assessed at 90ºs-1. Consequently, it is possible to conclude that combining general strength-training with plyometric exercises can not only increase lower limb strength and improve VJ performance but also reduce body fat content. PMID:25114739

Strength changes induced by extreme dieting and exercise in severely obese females.

PubMed

Pronk, N P; Donnelly, J E; Pronk, S J

1992-04-01

Strength changes, induced by very low-calorie diet (VLCD, 520 kcal/day) alone and in combination with exercise, were determined in 109 severely obese females (46.8 +/- 4.69% fat). Experimental treatments included VLCD alone (LC, n = 40), VLCD with endurance exercise (EE, n = 23), VLCD with endurance exercise and resistance strength training (EERST, n = 23), and VLCD with resistance strength training (RST, n = 23). All subjects participated in the study for 90 days while EE, EERST, and RST exercised four times/week according to specified schedules. Results indicated significant differences for the change scores (baseline to 90 days) for bench press, knee flexion, upper body and lower body composite strength scores between RST and all other groups. RST was the only treatment that increased upper and lower body strength. No differences between groups were found for body mass losses, decrease in percent fat and fat mass. In contrast, these variables showed significant change scores for all groups. Decreases in fat-free mass (FFM) were 5.18 +/- 3.40 kg, 4.79 +/- 4.15 kg (p = 0.001), 4.64 +/- 4.23 kg, and 3.26 +/- 2.67 kg for EE, LC, RST, and EERST, respectively. These data suggest that the combination of resistance strength training and VLCD increases strength despite a loss of FFM. However, endurance exercise and VLCD do not seem to affect body mass loss or FFM loss per se. Moreover, it seems that these increases in strength may represent a training effect which might imply improved central neuromuscular function rather than muscular hypertrophy since FFM decreased in all groups.