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Sample records for adolescent sprint athletes

  1. Lower extremity kinematics of athletics curve sprinting.

    PubMed

    Alt, Tobias; Heinrich, Kai; Funken, Johannes; Potthast, Wolfgang

    2015-01-01

    Curve running requires the generation of centripetal force altering the movement pattern in comparison to the straight path run. The question arises which kinematic modulations emerge while bend sprinting at high velocities. It has been suggested that during curve sprints the legs fulfil different functions. A three-dimensional motion analysis (16 high-speed cameras) was conducted to compare the segmental kinematics of the lower extremity during the stance phases of linear and curve sprints (radius: 36.5 m) of six sprinters of national competitive level. Peak joint angles substantially differed in the frontal and transversal plane whereas sagittal plane kinematics remained unchanged. During the prolonged left stance phase (left: 107.5 ms, right: 95.7 ms, straight: 104.4 ms) the maximum values of ankle eversion (left: 12.7°, right: 2.6°, straight: 6.6°), hip adduction (left: 13.8°, right: 5.5°, straight: 8.8°) and hip external rotation (left: 21.6°, right: 12.9°, straight: 16.7°) were significantly higher. The inside leg seemed to stabilise the movement in the frontal plane (eversion-adduction strategy) whereas the outside leg provided and controlled the motion in the horizontal plane (rotation strategy). These results extend the principal understanding of the effects of curve sprinting on lower extremity kinematics. This helps to increase the understanding of nonlinear human bipedal locomotion, which in turn might lead to improvements in athletic performance and injury prevention. PMID:25495196

  2. Acute Responses to 10×15 m Repeated Sprint Ability Exercise in Adolescent Athletes: the Role of Change of Direction and Sport Specialization

    PubMed Central

    Nikolaidis, Pantelis Theodoros; Meletakos, Panagiotis; Tasiopoulos, Ioannis; Kostoulas, Ioannis; Ganavias, Panagiotis

    2016-01-01

    Background The repeated sprint ability (RSA) has been studied with protocols using distances longer than 20 m per sprint, whereas basketball players cover on average less than 20-meter distance per sprint during match. Objectives The aim of the present study was to examine the physiological impact of 10 × 15 m RSA test in straight-line (RSASL) or with change of direction (RSACOD), i.e. 10 × (7.5 + 7.5 m)) in young national level basketball players. Patients and Methods Young basketball players (n = 11, age 17.1 (1.0) years, body mass 76 (6) kg, height 184 (4) cm, body mass index 22.6 (1.8) kgm-2, sport experience 6.9 (2.7) years, mean (standard deviation)) and a control group consisting of high-school athletes (n = 7, 16.1 (0.7) years, 67 (6) kg, 177 (6) cm, 21.5 (1.0) kgm-2, 7.7 (1.6) years, respectively) performed RSASL and RSACOD on a counter-balanced order. Sprints started every 30 seconds (active recovery) and there was 30 minutes break between RSA protocols; time variables were total time (TT), best time (BT) and fatigue index (FI). Countermovement jump (CMJ) was tested before and after each RSA protocol. Heart rate (HR) was continuously monitored during testing procedures. Results Compared with RSASL, TT and BT were worst in RSACOD (38.13 vs. 27.52 s and 3.67 vs. 2.66 s, P < 0.001, respectively), whereas FI did not differ (3.8 vs. 3.5%, P = 0.388). A 2 × 2 repeated measures ANOVA showed main effect of RSA on CMJ (pre-test vs. post-test, increase + 1.8 cm, P = 0.020, η2 = 0.28); there was neither main effect of RSA protocols (RSASL vs. RSACOD +0.7 cm, P = 0.251, η2 = 0.08) nor an interaction between pre-post measurements and RSA protocols (P = 0.578, η2 = 0.02). Compared with RSASL, RSACOD induced higher mean and peak HR responses (175 vs 172 bpm, P < 0.001, and 185 vs 182 bpm, P = 0.002, respectively). No statistical difference was observed between basketball players and control group neither for TT (27.98 vs. 26.80 seconds, + 4.4%, P = 0.149) and BT

  3. Physiological characteristics of well-trained junior sprint kayak athletes.

    PubMed

    Borges, Thiago Oliveira; Dascombe, Ben; Bullock, Nicola; Coutts, Aaron J

    2015-07-01

    This study aimed to profile the physiological characteristics of junior sprint kayak athletes (n=21, VO2max 4.1±0.7 L/min, training experience 2.7±1.2 y) and to establish the relationship between physiological variables (VO2max, VO2 kinetics, muscle-oxygen kinetics, paddling efficiency) and sprint kayak performance. VO2max, power at VO2max, power:weight ratio, paddling efficiency, VO2 at lactate threshold, and whole-body and muscle oxygen kinetics were determined on a kayak ergometer in the laboratory. Separately, on-water time trials (TT) were completed over 200 m and 1000 m. Large to nearly perfect (-.5 to -.9) inverse relationships were found between the physiological variables and on-water TT performance across both distances. Paddling efficiency and lactate threshold shared moderate to very large correlations (-.4 to -.7) with 200- and 1000-m performance. In addition, trivial to large correlations (-.11 to -.5) were observed between muscle-oxygenation parameters, muscle and whole-body oxygen kinetics, and performance. Multiple regression showed that 88% of the unadjusted variance for the 200-m TT performance was explained by VO2max, peripheral muscle deoxygenation, and maximal aerobic power (P<.001), whereas 85% of the unadjusted variance in 1000-m TT performance was explained by VO2max and deoxyhemoglobin (P<.001). The current findings show that well-trained junior sprint kayak athletes possess a high level of relative aerobic fitness and highlight the importance of the peripheral muscle metabolism for sprint kayak performance, particularly in 200-m races, where finalists and nonfinalists are separated by very small margins. Such data highlight the relative aerobic-fitness variables that can be used as benchmarks for talent-identification programs or monitoring longitudinal athlete development. However, such approaches need further investigation. PMID:25473923

  4. ADHD and Adolescent Athletes

    PubMed Central

    Nazeer, Ahsan; Mansour, Miriam; Gross, Kathleen A.

    2014-01-01

    Attention-deficit hyperactivity disorder (ADHD) is a common neurodevelopmental disorder that affects the child and adolescent population. It is characterized by impairment in attention/concentration, hyperactivity, and impulsivity, all of which can impact performance of athletes. ADHD treatment within the athletic population is a unique challenge. The research in this field has been relatively limited. The National Collegiate Athletic Association and International Olympic Committee both regulate the use of psychostimulants for treatment of ADHD due to their performance-enhancing effects. In this article, authors have discussed the screening methods, pharmacological treatment, side effects, and behavioral approaches for the treatment of ADHD in adolescent athletes. PMID:24987666

  5. Athletic Engagement and Athletic Identity in Top Croatian Sprint Runners.

    PubMed

    Babić, Vesna; Sarac, Jelena; Missoni, Sasa; Sindik, Josko

    2015-09-01

    The aim of the research was to determine construct validity and reliability for two questionnaires (Athlete Engagement Questionnaire-AEQ and Athletic Identity Measurement Scale-AIMS), applied on elite Croatian athletes-sprinters, as well as the correlations among the dimensions in these measuring instruments. Then, we have determined the differences in the dimensions of sport engagement and sport identity, according to gender, education level and winning medals on international competitions. A total of 71 elite athletes-sprinters (former and still active) are examined, from which 27 (38%) females and 44 (62%) males. The results of factor analyses revealed the existence of dimensions very similar as in the original instruments, which showed moderate to-high reliabilities. A small number of statistically significant correlations have been found between the dimensions of sport engagement and sport identity, mainly in male sprinter runners. Small number of statistically significant differences in the dimensions of sport engagement and sport identity have been found according to the gender, education level and winning medals on the international competitions. The most reasonable explanation of these differences could be given in terms of very similar characteristics of elite athletes on the same level of sport excellence. PMID:26898045

  6. Eating Disorders in Adolescent Athletes.

    ERIC Educational Resources Information Center

    Patel, Dilip R.; Greydanus, Donald E.; Pratt, Helen D.; Phillips, Elaine L.

    2003-01-01

    Reviews research on eating disorders in adolescent athletes, including prevalence, its uncommonness among male athletes, risk factors, medical complications, prevention strategies, and implications for sport and exercise participation, management, and prognosis. (EV)

  7. ACTN3 R577X genotype is associated with sprinting in elite Japanese athletes.

    PubMed

    Mikami, E; Fuku, N; Murakami, H; Tsuchie, H; Takahashi, H; Ohiwa, N; Tanaka, H; Pitsiladis, Y P; Higuchi, M; Miyachi, M; Kawahara, T; Tanaka, M

    2014-02-01

    The ACTN3 R577X genotype has been found to associate with sprint/power phenotypes in all elite athlete cohorts investigated. This association has not been extensively studied in elite Asian athletes. The present study was undertaken to investigate the association between the ACTN3 R577X genotype and elite Japanese track and field athlete status. 299 elite Japanese track and field athletes (134 sprint/power athletes; 165 endurance/middle-power athletes) and 649 Japanese controls were genotyped for the ACTN3 R577X polymorphism. All athletes were of national or international level. Sprint/power athletes showed a higher frequency of RR + RX genotype than controls (111/134 [82.8%] vs. 478/649 [73.7%], P = 0.025 under the R-dominant model), while there was no significant difference between endurance/middle-power athletes and controls (126/165 [76.4%] vs. 478/649 [73.7%], P = 0.48 under the R-dominant model). Sprinters with the RR + RX genotype had significantly faster personal best times for the 100 m than those with XX genotype (10.42 ± 0.05 s vs. 10.64 ± 0.09 s, P = 0.042); no such association was found in the 400 m sprinters (47.02 ± 0.36 s vs. 47.56 ± 0.99 s, P = 0.62). ACTN3 R577X genotype is associated with sprint/power performance in elite Japanese track and field athletes, especially short sprint performance. PMID:23868678

  8. Effects of sprint and plyometric training on muscle function and athletic performance.

    PubMed

    Markovic, Goran; Jukic, Igor; Milanovic, Dragan; Metikos, Dusan

    2007-05-01

    The purpose of this study was to evaluate the effects of sprint training on muscle function and dynamic athletic performance and to compare them with the training effects induced by standard plyometric training. Male physical education students were assigned randomly to 1 of 3 groups: sprint group (SG; n = 30), plyometric group (PG; n = 30), or control group (CG; n = 33). Maximal isometric squat strength, squat- and countermovement jump (SJ and CMJ) height and power, drop jump performance from 30-cm height, and 3 athletic performance tests (standing long jump, 20-m sprint, and 20-yard shuttle run) were measured prior to and after 10 weeks of training. Both experimental groups trained 3 days a week; SG performed maximal sprints over distances of 10-50 m, whereas PG performed bounce-type hurdle jumps and drop jumps. Participants in the CG group maintained their daily physical activities for the duration of the study. Both SG and PG significantly improved drop jump performance (15.6 and 14.2%), SJ and CMJ height ( approximately 10 and 6%), and standing long jump distance (3.2 and 2.8%), whereas the respective effect sizes (ES) were moderate to high and ranged between 0.4 and 1.1. In addition, SG also improved isometric squat strength (10%; ES = 0.4) and SJ and CMJ power (4%; ES = 0.4, and 7%; ES = 0.4), as well as sprint (3.1%; ES = 0.9) and agility (4.3%; ES = 1.1) performance. We conclude that short-term sprint training produces similar or even greater training effects in muscle function and athletic performance than does conventional plyometric training. This study provides support for the use of sprint training as an applicable training method of improving explosive performance of athletes in general. PMID:17530960

  9. The adolescent. Athletics and development.

    PubMed

    Masland, R P

    1983-01-01

    An appreciation of adolescent growth and development is essential to the understanding of problems faced by the adolescent athlete. Early adolescence (ages 10-15 years) can be characterized as the body period. Physical growth is genetically determined and can be influenced by disease, injury, and nutrition. Early maturers are subject to adult expectations which may lead to either failure or excessive acclaim. Middle adolescence (ages 15-18 years) is the sexuality period, with special emphasis on gender identity. Friendships are critical, and athletics can be a focal point for showing love and affection without social fear. Late adolescence (ages 18-22 years) is the separation period. Young people with athletic skills leave home to face greater athletic and academic pressure and competition in college. Adjustment to this final adolescent period is achieved through learning to lose as well as win with grace and dignity. PMID:6833060

  10. The influence of ego depletion on sprint start performance in athletes without track and field experience

    PubMed Central

    Englert, Chris; Persaud, Brittany N.; Oudejans, Raôul R. D.; Bertrams, Alex

    2015-01-01

    We tested the assumption that ego depletion would affect the sprint start in a sample of N = 38 athletes without track and field experience in an experiment by applying a mixed between- (depletion vs. non-depletion) within- (T1: before manipulation of ego depletion vs. T2: after manipulation of ego depletion) subjects design. We assumed that ego depletion would increase the possibility for a false start, as regulating the impulse to initiate the sprinting movement too soon before the starting signal requires self-control. In line with our assumption, we found a significant interaction as there was only a significant increase in the number of false starts from T1 to T2 for the depletion group while this was not the case for the non-depletion group. We conclude that ego depletion has a detrimental influence on the sprint start in athletes without track and field experience. PMID:26347678

  11. Effects of red bull energy drink on repeated sprint performance in women athletes.

    PubMed

    Astorino, Todd A; Matera, Angela J; Basinger, Jency; Evans, Mindy; Schurman, Taylor; Marquez, Rodney

    2012-05-01

    Energy drinks are frequently consumed by athletes prior to competition to improve performance. This study examined the effect of Red Bull™ on repeated sprint performance in women athletes. Fifteen collegiate soccer players participated, with mean age, height, and body mass equal to 19.5±1.1 year, 168.4±5.8 cm, and 63.4±6.1 kg, respectively. After performing a familiarization trial, subjects performed three sets of eight bouts of the modified t test after ingestion of 255 mL of placebo or Red Bull 1 h pre-exercise in a randomized, placebo-controlled crossover design. Throughout testing, sprint time, heart rate (HR), and rating of perceived exertion (RPE) were continuously obtained. Repeated measures analysis of variance was used to examine differences in variables between drink conditions. Across athletes, t test time ranged from 10.4 to 12.7 s. Mean sprint time was similar (p>0.05) between Red Bull (11.31±0.61 s) and placebo (11.35±0.61 s). HR and RPE increased (p<0.05) during the bouts, but there was no effect (p>0.05) of Red Bull on either variable versus placebo. Findings indicate that 255 mL of Red Bull containing 1.3 mg/kg of caffeine and 1 g of taurine does not alter repeated sprint performance, RPE, or HR in women athletes versus placebo. One serving of this energy drink provides no ergogenic benefit for women athletes engaging in sprint-based exercise. PMID:21461905

  12. Sprint-based exercise and cognitive function in adolescents.

    PubMed

    Cooper, Simon B; Bandelow, Stephan; Nute, Maria L; Dring, Karah J; Stannard, Rebecca L; Morris, John G; Nevill, Mary E

    2016-12-01

    Moderate intensity exercise has been shown to enhance cognition in an adolescent population, yet the effect of high-intensity sprint-based exercise remains unknown and was therefore examined in the present study. Following ethical approval and familiarisation, 44 adolescents (12.6 ± 0.6 y) completed an exercise (E) and resting (R) trial in a counter-balanced, randomised crossover design. The exercise trial comprised of 10 × 10 s running sprints, interspersed by 50 s active recovery (walking). A battery of cognitive function tests (Stroop, Digit Symbol Substitution (DSST) and Corsi blocks tests) were completed 30 min pre-exercise, immediately post-exercise and 45 min post-exercise. Data were analysed using mixed effect models with repeated measures. Response times on the simple level of the Stroop test were significantly quicker 45 min following sprint-based exercise (R: 818 ± 33 ms, E: 772 ± 26 ms; p = 0.027) and response times on the complex level of the Stroop test were quicker immediately following the sprint-based exercise (R: 1095 ± 36 ms, E: 1043 ± 37 ms; p = 0.038), while accuracy was maintained. Sprint-based exercise had no immediate or delayed effects on the number of items recalled on the Corsi blocks test (p = 0.289) or substitutions made during the DSST (p = 0.689). The effect of high intensity sprint-based exercise on adolescents' cognitive function was dependant on the component of cognitive function examined. Executive function was enhanced following exercise, demonstrated by improved response times on the Stroop test, whilst visuo-spatial memory and general psycho-motor speed were unaffected. These data support the inclusion of high-intensity sprint-based exercise for adolescents during the school day to enhance cognition. PMID:27413677

  13. AMPD1 rs17602729 is associated with physical performance of sprint and power in elite Lithuanian athletes

    PubMed Central

    2014-01-01

    Background The C34T genetic polymorphism (rs17602729) in the AMPD1 gene, encoding the skeletal muscle-specific isoform of adenosine monophosphate deaminase (AMPD1), is a common polymorphism among Caucasians that can impair exercise capacity. The aim of the present study was twofold: (1) to determine the C34T AMPD1 allele/genotype frequency distributions in Lithuanian athletes (n = 204, stratified into three groups: endurance, sprint/power and mixed) and compare them with the allele/genotype frequency distributions in randomly selected healthy Lithuanian non-athletes (n = 260) and (2) to compare common anthropometric measurements and physical performance phenotypes between the three groups of athletes depending on their AMPD1 genotype. Results The results of our study indicate that the frequency of the AMPD1 TT genotype was 2.4% in the control group, while it was absent in the athlete group. There were significantly more sprint/power-orientated athletes with the CC genotype (86.3%) compared with the endurance-orientated athletes (72.9%), mixed athletes (67.1%), and controls (74.2%). We determined that the AMPD1 C34T polymorphism is not associated with aerobic muscle performance phenotype (VO2max). For CC genotype the short-term explosive muscle power value (based on Vertical Jump test) of athletes from the sprint/power group was significantly higher than that of the endurance group athletes (P < 0.05). The AMPD1 CC genotype is associated with anaerobic performance (Vertical Jump). Conclusions The AMPD1 C allele may help athletes to attain elite status in sprint/power-oriented sports, and the T allele is a factor unfavourable for athletics in sprint/power-oriented sports categories. Hence, the AMPD1 C allele can be regarded as a marker associated with the physical performance of sprint and power. Replications studies are required to confirm this association. PMID:24885427

  14. Sprint mechanics in world-class athletes: a new insight into the limits of human locomotion.

    PubMed

    Rabita, G; Dorel, S; Slawinski, J; Sàez-de-Villarreal, E; Couturier, A; Samozino, P; Morin, J-B

    2015-10-01

    The objective of this study was to characterize the mechanics of maximal running sprint acceleration in high-level athletes. Four elite (100-m best time 9.95-10.29 s) and five sub-elite (10.40-10.60 s) sprinters performed seven sprints in overground conditions. A single virtual 40-m sprint was reconstructed and kinetics parameters were calculated for each step using a force platform system and video analyses. Anteroposterior force (FY), power (PY), and the ratio of the horizontal force component to the resultant (total) force (RF, which reflects the orientation of the resultant ground reaction force for each support phase) were computed as a function of velocity (V). FY-V, RF-V, and PY-V relationships were well described by significant linear (mean R(2) of 0.892 ± 0.049 and 0.950 ± 0.023) and quadratic (mean R(2) = 0.732 ± 0.114) models, respectively. The current study allows a better understanding of the mechanics of the sprint acceleration notably by modeling the relationships between the forward velocity and the main mechanical key variables of the sprint. As these findings partly concern world-class sprinters tested in overground conditions, they give new insights into some aspects of the biomechanical limits of human locomotion. PMID:25640466

  15. Five Weeks of Sprint and High-Intensity Interval Training Improves Paddling Performance in Adolescent Surfers.

    PubMed

    Farley, Oliver R L; Secomb, Josh L; Parsonage, Joanna R; Lundgren, Lina E; Abbiss, Chris R; Sheppard, Jeremy M

    2016-09-01

    Farley, ORL, Secomb, JL, Parsonage, JR, Lundgren, LE, Abbiss, CR, and Sheppard, JM. Five weeks of sprint and high-intensity interval training improves paddling performance in adolescent surfers. J Strength Cond Res 30(9): 2446-2452, 2016-The purpose of our study was to examine the effects of sprint interval training (SIT; 10 seconds) and high-intensity interval training (HIT; 30 seconds) on surfing athletes paddling performance (400-m time trial and repeat-sprint paddle performance). Twenty-four competitive adolescent surfers (19 male, 5 female; age = 14.4 ± 1.3 years, mass: 50.1 ± 10.7 kg, and stature: 159.9 ± 10.3 cm) were assigned to perform either 5 weeks of SIT and HIT. Participants completed a repeated-sprint paddle ability test (RSPT, 15-m surfboard sprint paddle initiated every 40 seconds × 10 bouts) and 400-m endurance surfboard paddle time trial before and after training. High-intensity interval training decreased the total time to complete the 400 m by 15.8 ± 16.1 seconds (p = 0.03), and SIT decreased the total time to complete the RSPT by 6.5 ± 4.3 seconds (p = 0.02). Fatigue index during the RSPT (first-slowest effort) was lower after HIT and SIT (p ≤ 0.001 and p = 0.02, respectively). There were no significant differences in performance changes in the 400 m (total time) and RSPT (total time, fastest 15 m time, and peak velocity) between HIT and SIT. Our study indicates that HIT and SIT may be implemented to the training program of surfers to improve aerobic and repeat-sprint paddle ability, both of which are identified as key aspects of the sport. In addition, these findings indicate that 400-m paddle and RSPT can discriminate between aerobic and anaerobic training adaptations, with aerobic gains likely from HIT and anaerobic gains from SIT. PMID:26849794

  16. Interrelationships between different loads in resisted sprints, half-squat 1 RM and kinematic variables in trained athletes.

    PubMed

    Martínez-Valencia, María Asunción; González-Ravé, José M; Santos-García, Daniel Juárez; Alcaraz Ramón, Pedro E; Navarro-Valdivielso, Fernando

    2014-01-01

    Resisted sprint running is a common training method for improving sprint-specific strength. It is well-known that an athlete's time to complete a sled-towing sprint increases linearly with increasing sled load. However, to our knowledge, the relationship between the maximum load in sled-towing sprint and the sprint time is unknown, The main purpose of this research was to analyze the relationship between the maximum load in sled-towing sprint, half-squat maximal dynamic strength and the velocity in the acceleration phase in 20-m sprint. A second aim was to compare sprint performance when athletes ran under different conditions: un-resisted and towing sleds. Twenty-one participants (17.86 ± 2.27 years; 1.77 ± 0.06 m and 69.24 ± 7.20 kg) completed a one repetition maximum test (1 RM) from a half-squat position (159.68 ± 22.61 kg) and a series of sled-towing sprints with loads of 0, 5, 10, 15, 20, 25, 30% body mass (Bm) and the maximum resisted sprint load. No significant correlation (P<0.05) was found between half-squat 1 RM and the sprint time in different loaded conditions. Conversely, significant correlations (P<0.05) were found between maximum load in resisted sprint and sprint time (20-m sprint time, r=-0.71; 5% Bm, r=-0.73; 10% Bm, r=-0.53; 15% Bm, r=-0.55; 20% Bm, r=-0.65; 25% Bm, r=-0.44; 30% Bm, r=-0.63; MaxLoad, r= 0.93). The sprinting velocity significantly decreased by 4-22% with all load increases. Stride length (SL) also decreased (17%) significantly across all resisted conditions. In addition, there were significant differences in stride frequency (SF) with loads over 15% Bm. It could be concluded that the knowledge of the individual maximal load in resisted sprint and the effects on the sprinting kinematic with different loads, could be interesting to determinate the optimal load to improve the acceleration phase at sprint running. PMID:24444204

  17. Acute Effects of Loaded Half-Squat Jumps on Sprint Running Speed in Track and Field Athletes and Soccer Players.

    PubMed

    Vanderka, Marián; Krčmár, Matúš; Longová, Katarína; Walker, Simon

    2016-06-01

    Vanderka, M, Krčmár, M, Longová, K, and Walker, S. Acute effects of loaded half-squat jumps on sprint running speed in track and field athletes and soccer players. J Strength Cond Res 30(6): 1540-1546, 2016-The purpose of the study was to determine the acute responses to a jump squat protocol designed to induce postactivation potentiation on sprint running performance in experienced track and field athletes and soccer players. Twenty-five regional level athletes (12 track and field: ∼17 years; ∼177 cm; ∼73 kg and 13 soccer: ∼18 years; ∼175 cm; ∼72 kg) performed 2 test sessions assessing 40-m sprint running performance in a balanced, crossover design. Dual-beam light timing gates measured 0-20 and 20-40 m sprint times before and after either 9 minutes of sitting (control) or 2 sets of 6 repetition half-squat jump with the load eliciting maximum power (experimental) conditions. Sprint performance was significantly enhanced over both 0-20 m (3.09 ± 0.07 to 3.04 ± 0.08 seconds; Δ ∼1.5%; p ≤ 0.05) and 20-40 m (2.42 ± 0.09 to 2.39 ± 0.09 seconds; Δ ∼1%; p ≤ 0.05) in track and field athletes only. Also, the magnitude of enhanced sprint performance was related to baseline 0-20 m sprint performance (r = 0.44; p = 0.028; n = 25). It seems that using loaded half-squat jumps to enhance sprint performance could be used in training of high-level young athletes. PMID:26562707

  18. Relative Age Effects in Athletic Sprinting and Corrective Adjustments as a Solution for Their Removal

    PubMed Central

    2015-01-01

    Relative Age Effects (RAEs) refer to the selection and performance differentials between children and youth who are categorized in annual-age groups. In the context of Swiss 60m athletic sprinting, 7761 male athletes aged 8 – 15 years were analysed, with this study examining whether: (i) RAE prevalence changed across annual age groups and according to performance level (i.e., all athletes, Top 50%, 25% & 10%); (ii) whether the relationship between relative age and performance could be quantified, and corrective adjustments applied to test if RAEs could be removed. Part one identified that when all athletes were included, typical RAEs were evident, with smaller comparative effect sizes, and progressively reduced with older age groups. However, RAE effect sizes increased linearly according to performance level (i.e., all athletes – Top 10%) regardless of age group. In part two, all athletes born in each quartile, and within each annual age group, were entered into linear regression analyses. Results identified that an almost one year relative age difference resulted in mean expected performance differences of 10.1% at age 8, 8.4% at 9, 6.8% at 10, 6.4% at 11, 6.0% at 12, 6.3% at 13, 6.7% at 14, and 5.3% at 15. Correction adjustments were then calculated according to day, month, quarter, and year, and used to demonstrate that RAEs can be effectively removed from all performance levels, and from Swiss junior sprinting more broadly. Such procedures could hold significant implications for sport participation as well as for performance assessment, evaluation, and selection during athlete development. PMID:25844642

  19. A Clustered Repeated-Sprint Running Protocol for Team-Sport Athletes Performed in Normobaric Hypoxia

    PubMed Central

    Morrison, Jaime; McLellan, Chris; Minahan, Clare

    2015-01-01

    The present study compared the performance (peak speed, distance, and acceleration) of ten amateur team-sport athletes during a clustered (i.e., multiple sets) repeated-sprint protocol, (4 sets of 4, 4-s running sprints; i.e., RSR444) in normobaric normoxia (FiO2 = 0.209; i.e., RSN) with normobaric hypoxia (FiO2 = 0.140; i.e., RSH). Subjects completed two separate trials (i. RSN, ii. RSH; randomised order) between 48 h and 72 h apart on a non-motorized treadmill. In addition to performance, we examined blood lactate concentration [La-] and arterial oxygen saturation (SpO2) before, during, and after the RSR444. While there were no differences in peak speed or distance during set 1 or set 2, peak speed (p = 0.04 and 0.02, respectively) and distance (p = 0.04 and 0.02, respectively) were greater during set 3 and set 4 of RSN compared with RSH. There was no difference in the average acceleration achieved in set 1 (p = 0.45), set 2 (p = 0.26), or set 3 (p = 0.23) between RSN and RSH; however, the average acceleration was greater in RSN than RSH in set 4 (p < 0.01). Measurements of [La-] were higher during RSH than RSN immediately after Sprint 16 (10.2 ± 2.5 vs 8.6 ± 2.6 mM; p = 0.02). Estimations of SpO2 were lower during RSH than RSN, respectively, immediately prior to the commencement of the test (89.0 ± 2.0 vs 97.2 ± 1.5 %), post Sprint 8 (78.0 ± 6.3 vs 93.8 ± 3.6 %) and post Sprint 16 (75.3 ± 6.3 vs 94.5 ± 2.5 %; all p < 0.01). In summary, the RSR444 is a practical protocol for the implementation of a hypoxic repeated-sprint training intervention into the training schedules of team-sport athletes. However, given the inability of amateur team-sport athletes to maintain performance in hypoxic (FiO2 = 0.140) conditions, the potential for specific training outcomes (i.e. speed) to be achieved will be compromised, thus suggesting that the RSR444 should be used with caution. Key points The RSR444 is a practical, multiple-set repeated-sprint running protocol

  20. Effect of long haul travel on maximal sprint performance and diurnal variations in elite skeleton athletes

    PubMed Central

    Bullock, Nicola; Martin, David T; Ross, Angus; Rosemond, Doug; Marino, Frank E

    2007-01-01

    Objective To quantify the impact of eastward long haul travel on diurnal variations in cortisol, psychological sensations and daily measurements of physical performance. Methods Five elite Australian skeleton athletes undertook a long haul eastward flight from Australia to Canada (LHtravel), while seven elite Canadian skeleton athletes did not travel (NOtravel). Salivary cortisol was measured on awakening, 60 min and 120 min after awakening. Psychological sensations were measured with a questionnaire, and maximal 30 m sprints were performed once a day between 09:30 and 11:00 h local time. Results Compared with baseline, average (SD) resting salivary cortisol decreased by 67% immediately after long haul travel (23.43 (5.71) nMol/l) (mean±90% confidence interval) in the LHtravel group (p = 0.03), while no changes were found in the NOtravel group (p = 0.74). There were no significant differences in 30 m sprint time between baseline and post‐flight tests in the LHtravel group (p>0.05). The LHtravel group perceived themselves as “jet lagged” for up to 2 days after the flight (p = 0.01 for both midday lunch and evening dinner). Conclusions Despite a distinct phase change in salivary cortisol rhythmicity and the athletes perceiving themselves as “jet lagged”, minimal disturbances in “one‐off” maximal sprinting ability between 09:30 and 11:00 h local time were seen in a group of elite skeleton athletes after long haul eastward travel from Australia to Canada. PMID:17473002

  1. Repeated Sprint Performance in Male and Female College Athletes Matched for VO2max Relative to Fat Free Mass

    PubMed Central

    MAGEEAN, AMANDA L.; ALEXANDER, RYAN P.; MIER, CONSTANCE M.

    2011-01-01

    The purpose of this study was to examine gender differences in repeated sprint exercise (RSE) performance among male and female athletes matched for VO2max relative to FFM (VO2max FFM). Thirty nine male and female college athletes performed a graded exercise test for VO2max and hydrostatic weighing to determine FFM. From the results, 11 pairs of males and females matched for VO2max FFM (mean ± SD; 58.3 ± 4.3 and 58.9 ± 4.6 ml·kg FFM−1·min−1; men and women, respectively) were identified. On a separate day, matched participants performed a RSE protocol that consisted of five 6-sec cycle sprints with 30-sec recovery periods, followed by 5-min active recovery and a 30-sec all-out sprint. Repeated 6-sec sprint performance did not differ between men and women; both maintained power output (PO) until sprint 4. POFFM (W·kg−1 FFM) did not differ between men and women during the five sprints. During the 30-sec sprint, men achieved a lower peak POFFM than women (11.7 ± 1.5 vs 13.2 ± 1.2); however, the decline in POFFM over 30 sec was greater in women. VO2 (ml·kg FFM−1·min−1) was lower in men during recovery (24.4 ± 3.8 vs 28.7 ± 5.7) and at the beginning (29.2 ± 4.0 vs 34.7 ± 4.9) and end (49.4 ± 5.0 vs 52.3 ± 4.0). of the 30-sec sprint. These data indicate that men and women with similar aerobic capacities do not respond differently to short repeated sprints but may differ in their ability to recover and perform sprints of longer duration. PMID:27182366

  2. Aerobic and anaerobic determinants of repeated sprint ability in team sports athletes.

    PubMed

    Gharbi, Z; Dardouri, W; Haj-Sassi, R; Chamari, K; Souissi, N

    2015-09-01

    The aim of this study was to examine in team sports athletes the relationship between repeated sprint ability (RSA) indices and both aerobic and anaerobic fitness components. Sixteen team-sport players were included (age, 23.4 ± 2.3 years; weight, 71.2 ± 8.3 kg; height, 178 ± 7 cm; body mass index, 22.4 ± 2 kg · m(-2); estimated VO2max, 54.16 ± 3.5 mL · kg(-1) · min(-1)). Subjects were licensed in various team sports: soccer (n = 8), basketball (n = 5), and handball (n = 3). They performed 4 tests: the 20 m multi-stage shuttle run test (MSRT), the 30-s Wingate test (WingT), the Maximal Anaerobic Shuttle Running Test (MASRT), and the RSA test (10 repetitions of 30 m shuttle sprints (15 + 15 m with 180° change of direction) with 30 s passive recovery in between). Pearson's product moment of correlation among the different physical tests was performed. No significant correlations were found between any RSA test indices and WingT. However, negative correlations were found between MASRT and RSA total sprint time (TT) and fatigue index (FI) (r = -0.53, p < 0.05 and r = -0.65, p < 0.01, respectively). No significant relationship between VO2max and RSA peak sprint time (PT) and total sprint time (TT) was found. Nevertheless, VO2max was significantly correlated with the RSA FI (r = -0.57, p < 0.05). In conclusion, aerobic fitness is an important factor influencing the ability to resist fatigue during RSA exercise. Our results highlighted the usefulness of MASRT, in contrast to WingT, as a specific anaerobic testing procedure to identify the anaerobic energy system contribution during RSA. PMID:26424923

  3. Adolescent Athletic Injuries: Diagnosis and Management

    PubMed Central

    White, G. N.

    1986-01-01

    Adolescents are becoming involved in athletic activities at an ever-increasing rate, with the result that more adolescents are presenting to the family physician with athletic injuries. The most frequent type of sports injury involves the soft tissues. This paper discusses the diagnosis and management of soft-tissue injuries and identifies some of the behavioural characteristics of the injured adolescent athlete. ImagesFigure 5Figure 6Figure 7Figure 8 PMID:21267223

  4. Acute consumption of p-synephrine does not enhance performance in sprint athletes.

    PubMed

    Gutiérrez-Hellín, Jorge; Salinero, Juan José; Abían-Vicen, Javier; Areces, Francisco; Lara, Beatriz; Gallo, Cesar; Puente, Carlos; Del Coso, Juan

    2016-01-01

    P-Synephrine is a protoalkaloid widely used as an ergogenic aid in sports. This substance has been included in the World Anti-Doping Agency monitoring program, although scientific information about its effects on performance and athletes' well-being is scarce. The purpose of this investigation was to determine the effectiveness of p-synephrine to increase performance in sprint athletes. In a randomized and counterbalanced order, 13 experienced sprinters performed 2 acute experimental trials after the ingestion of p-synephrine (3 mg·kg(-1)) or after the ingestion of a placebo (control trial). Forty-five minutes after the ingestion of the substances, the sprinters performed a squat jump, a countermovement jump, a 15-s repeated jump test, and subsequently performed 60-m and 100-m simulated sprint competitions. Self-reported questionnaires were used to assess side-effect prevalence. In comparison with the control trial, the ingestion of p-synephrine did not change countermovement jump height (37.4 ± 4.2 vs 36.7 ± 3.3 cm, respectively; P = 0.52), squat jump height (34.4 ± 3.6 vs 33.9 ± 3.7 cm; P = 0.34), or average 15-s repeated jumps height (31.8 ± 4.1 vs 32.2 ± 3.6 cm; P = 0.18). P-Synephrine did not modify maximal running speed during the 60-m (9.0 ± 0.5 vs 9.0 ± 0.4 m·s(-1), respectively; P = 0.55) and 100-m sprint competitions (8.8 ± 0.5 vs 8.8 ± 0.5 m·s(-1), respectively; P = 0.92). The ingestion of p-synephrine did not alter the prevalence of headache, gastrointestinal discomforts, muscle pain, or insomnia during the hours following the tests. Acute consumption of 3 mg·kg(-1) of p-synephrine was ineffective to increase performance in competitive sprint athletes. Moreover, p-synephrine did not increase the occurrence of side effects after the competition. PMID:26673246

  5. Acute effect of a complex training protocol of back squats on 30-m sprint times of elite male military athletes

    PubMed Central

    Ojeda, Álvaro Huerta; Ríos, Luis Chirosa; Barrilao, Rafael Guisado; Serrano, Pablo Cáceres

    2016-01-01

    [Purpose] The aim of this study was to determine the acute effect temporal of a complex training protocol on 30 meter sprint times. A secondary objective was to evaluate the fatigue indexes of military athletes. [Subjects and Methods] Seven military athletes were the subjects of this study. The variables measured were times in 30-meter sprint, and average power and peak power of squats. The intervention session with complex training consisted of 4 sets of 5 repetitions at 30% 1RM + 4 repetitions at 60% 1RM + 3 repetitions of 30 meters with 120-second rests. For the statistical analysis repeated measures of ANOVA was used, and for the post hoc analysis, student’s t-test was used. [Results] Times in 30 meter sprints showed a significant reduction between the control set and the four experimental sets, but the average power and peak power of squats did not show significant changes. [Conclusion] The results of the study show the acute positive effect of complex training, over time, in 30-meter sprint by military athletes. This effect is due to the post activation potentiation of the lower limbs’ muscles in the 30 meters sprint. PMID:27134353

  6. Low back pain in the adolescent athlete.

    PubMed

    De Luigi, Arthur Jason

    2014-11-01

    Clinicians must have knowledge of the growth and development of the adolescent spine and the subsequent injury patterns and other spinal conditions common in the adolescent athlete. The management and treatment of spinal injuries in adolescent athletes require a coordinated effort between the clinician, patients, parents/guardians, coaches, therapists, and athletic trainers. Treatment should not only help alleviate the current symptoms but also address flexibility and muscle imbalances to prevent future injuries by recognizing and addressing risk factors. Return to sport should be a gradual process once the pain has resolved and the athlete has regained full strength. PMID:25442158

  7. Aging, muscle fiber type, and contractile function in sprint-trained athletes.

    PubMed

    Korhonen, Marko T; Cristea, Alexander; Alén, Markku; Häkkinen, Keijo; Sipilä, Sarianna; Mero, Antti; Viitasalo, Jukka T; Larsson, Lars; Suominen, Harri

    2006-09-01

    Biopsy samples were taken from the vastus lateralis of 18- to 84-yr-old male sprinters (n = 91). Fiber-type distribution, cross-sectional area, and myosin heavy chain (MHC) isoform content were identified using ATPase histochemistry and SDS-PAGE. Specific tension and maximum shortening velocity (V(o)) were determined in 144 single skinned fibers from younger (18-33 yr, n = 8) and older (53-77 yr, n = 9) runners. Force-time characteristics of the knee extensors were determined by using isometric contraction. The cross-sectional area of type I fibers was unchanged with age, whereas that of type II fibers was reduced (P < 0.001). With age there was an increased MHC I (P < 0.01) and reduced MHC IIx isoform content (P < 0.05) but no differences in MHC IIa. Specific tension of type I and IIa MHC fibers did not differ between younger and older subjects. V(o) of fibers expressing type I MHC was lower (P < 0.05) in older than in younger subjects, but there was no difference in V(o) of type IIa MHC fibers. An aging-related decline of maximal isometric force (P < 0.001) and normalized rate of force development (P < 0.05) of knee extensors was observed. Normalized rate of force development was positively associated with MHC II (P < 0.05). The sprint-trained athletes experienced the typical aging-related reduction in the size of fast fibers, a shift toward a slower MHC isoform profile, and a lower V(o) of type I MHC fibers, which played a role in the decline in explosive force production. However, the muscle characteristics were preserved at a high level in the oldest runners, underlining the favorable impact of sprint exercise on aging muscle. PMID:16690791

  8. Features of Posttraumatic Distress Among Adolescent Athletes

    PubMed Central

    Perna, Frank M.

    2003-01-01

    Objective: To examine features of posttraumatic distress related to sport injury among healthy and injured adolescent athletes. Design and Setting: Healthy athletes with and without a prior injury history were screened before their competitive season, and injured and matched control athletes were surveyed at 1 week postinjury. Subjects: We screened 283 athletes during the preseason and categorized them by injury history (n = 43) and no injury history (n = 240) groups. Twenty-four athletes (12 injured, 12 matched uninjured controls) were included in the postinjury analysis. Measurements: The Impact of Events Scale, a 15-item self-report questionnaire, was used to measure athletes' frequency of experiencing intrusive thoughts and engaging in avoidance behavior regarding athletic injury. Results: Athletes with a recent injury history exhibited a greater frequency of intrusive thoughts and avoidance behavior than did those without a recent injury history. Although postinjury findings did not reach statistical significance, injured athletes' scores increased by 35% to 49% from preinjury to postinjury, whereas only minimal changes (<1%) occurred in the control group. Conclusions: Younger athletes may be particularly sensitive to injury-related stimuli, which may result in heightened injury-related distress. PMID:12937529

  9. ACVR1B rs2854464 Is Associated with Sprint/Power Athletic Status in a Large Cohort of Europeans but Not Brazilians.

    PubMed

    Voisin, Sarah; Guilherme, João Paulo F L; Yan, Xu; Pushkarev, Vladimir P; Cieszczyk, Pawel; Massidda, Myosotis; Calò, Carla M; Dyatlov, Dmitry A; Kolupaev, Vitaliy A; Pushkareva, Yuliya E; Maciejewska, Agnieszka; Sawczuk, Marek; Lancha, Antonio H; Artioli, Guilherme G; Eynon, Nir

    2016-01-01

    Skeletal muscle strength and mass, major contributors to sprint/power athletic performance, are influenced by genetics. However, to date, only a handful of genetic variants have been associated with sprint/power performance. The ACVR1B A allele (rs rs2854464) has previously been associated with increased muscle-strength in non-athletic cohort. However, no follow-up and/or replications studies have since been conducted. Therefore, the aim of the present study was to compare the genotype distribution of ACVR1B rs2854464 between endurance athletes (E), sprint/power (S/P) athletes, mixed athletes (M), and non-athletic control participants in 1672 athletes (endurance athletes, n = 482; sprint/power athletes, n = 578; mixed athletes, n = 498) and 1089 controls (C) of both European Caucasians (Italian, Polish and Russians) and Brazilians. We have also compared the genotype distribution according to the athlete's level of competition (elite vs. sub-elite). DNA extraction and genotyping were performed using various methods. Fisher's exact test (adjusted for multiple comparisons) was used to test whether the genotype distribution of rs2854464 (AA, AG and GG) differs between groups. The A allele was overrepresented in S/P athletes compared with C in the Caucasian sample (adjusted p = 0.048), whereas there were no differences in genotype distribution between E athletes and C, in neither the Brazilian nor the Caucasian samples (adjusted p > 0.05). When comparing all Caucasian athletes regardless of their sporting discipline to C, we found that the A allele was overrepresented in athletes compared to C (adjusted p = 0.024). This association was even more pronounced when only elite-level athletes were considered (adjusted p = 0.00017). In conclusion, in a relatively large cohort of athletes from Europe and South America we have shown that the ACVR1B rs2854464 A allele is associated with sprint/power performance in Caucasians but not in Brazilian athletes. This reinforces the

  10. Sprint Performance Changes and Determinants in Afro-Caribbean Adolescents Between 13 and 15 Years Old

    PubMed Central

    Copaver, Karine Babel; Hertogh, Claude; Hue, Olivier

    2012-01-01

    Afro-Caribbean sprinters often reach high performance levels at an early age. Adolescence is a time of morphological and physiological changes. This study was designed to analyze the evolution in parameters of short sprint performance during adolescence in Afro-Caribbean boys, especially the stride number/body height ratio (SN/BH), which is at the interface of technical and morphological factors. Seventy-one 13-year-old boys performed vertical jumps and short sprint races. The races were filmed with a view to determine stride variables. Anthropometric parameters were also measured. The same tests were performed two years later. Body height and SN/BH were the main predictors of sprint performance. The delta of performance was principally explained by stride length and stride number. Although deterioration in technical parameters was expected, the parameters related to body size and stride length were the main sprint performance predictors rather than explosive force. These results could be useful in developing tests to detect sprint potential in youth. PMID:23487285

  11. ACVR1B rs2854464 Is Associated with Sprint/Power Athletic Status in a Large Cohort of Europeans but Not Brazilians

    PubMed Central

    Voisin, Sarah; Guilherme, João Paulo F. L.; Yan, Xu; Pushkarev, Vladimir P.; Cieszczyk, Pawel; Massidda, Myosotis; Calò, Carla M.; Dyatlov, Dmitry A.; Kolupaev, Vitaliy A.; Pushkareva, Yuliya E.; Maciejewska, Agnieszka; Sawczuk, Marek; Lancha, Antonio H.; Artioli, Guilherme G.

    2016-01-01

    Skeletal muscle strength and mass, major contributors to sprint/power athletic performance, are influenced by genetics. However, to date, only a handful of genetic variants have been associated with sprint/power performance. The ACVR1B A allele (rs rs2854464) has previously been associated with increased muscle-strength in non-athletic cohort. However, no follow-up and/or replications studies have since been conducted. Therefore, the aim of the present study was to compare the genotype distribution of ACVR1B rs2854464 between endurance athletes (E), sprint/power (S/P) athletes, mixed athletes (M), and non-athletic control participants in 1672 athletes (endurance athletes, n = 482; sprint/power athletes, n = 578; mixed athletes, n = 498) and 1089 controls (C) of both European Caucasians (Italian, Polish and Russians) and Brazilians. We have also compared the genotype distribution according to the athlete’s level of competition (elite vs. sub-elite). DNA extraction and genotyping were performed using various methods. Fisher's exact test (adjusted for multiple comparisons) was used to test whether the genotype distribution of rs2854464 (AA, AG and GG) differs between groups. The A allele was overrepresented in S/P athletes compared with C in the Caucasian sample (adjusted p = 0.048), whereas there were no differences in genotype distribution between E athletes and C, in neither the Brazilian nor the Caucasian samples (adjusted p > 0.05). When comparing all Caucasian athletes regardless of their sporting discipline to C, we found that the A allele was overrepresented in athletes compared to C (adjusted p = 0.024). This association was even more pronounced when only elite-level athletes were considered (adjusted p = 0.00017). In conclusion, in a relatively large cohort of athletes from Europe and South America we have shown that the ACVR1B rs2854464 A allele is associated with sprint/power performance in Caucasians but not in Brazilian athletes. This reinforces the

  12. A group-enhanced sprint interval training program for amateur athletes.

    PubMed

    Martin, Luc J; Anderson, Scott H; Schmale, Matthew S; Hallworth, Jillian R; Hazell, Tom J

    2016-08-01

    Sprint interval training (SIT) can elicit improvements in aerobic and anaerobic capacity. While variations in SIT protocols have been investigated, the influence of social processes cannot be overlooked. As research supports the use of groups to influence individual cognitions and behaviours, the current project assessed the effectiveness of a group-based intervention with participants conducting SIT. Specifically, 53 amateur athletes (age, 21.9 ± 2.9 years; 53% females) took part in a 4-week training program (3 sessions per week, 30-s "all-out" efforts with 4 min active recovery, repeated 4-6 times per session), and were assigned to "true group", aggregate, or individual conditions. Results indicated no significant differences between groups for the physiological measures. With regards to training improvements from baseline for all participants- regardless of condition - significant main effects for time were identified for maximal oxygen uptake (2.5-2.8 mL·kg(-1)·min(-1), p < 0.001, η(2) = 0.03), time-trial performance (14-32 s, p < 0.001, η(2) = 0.37), and anaerobic power (1.1-1.7 k·h(-1), p < 0.001, η(2) = 0.66). With regards to the psychological measures, significant main effects between groups were found for motivation (p = 0.033, η(2) = 0.13), task self-efficacy (p = 0.018, η(2) = 0.15), and scheduling self-efficacy (p = 0.003, η(2) = 0.22). The true group experienced greater improvements in motivation than the individual condition, but the aggregate and individual conditions demonstrated greater increases in task and scheduling self-efficacy. Though the SIT paradigm employed induced training improvements similar to previous work, the group intervention was not able to further these improvements. PMID:27377136

  13. Coping Styles among Adolescent Competitive Athletes.

    ERIC Educational Resources Information Center

    Anshel, Mark

    1996-01-01

    Examines the various coping strategies that competitive adolescent athletes use to deal with errors, penalties, and unpleasant comments from spectators. Identifies and discusses four coping strategies: avoidance, approach, task-focused, and emotion-focused. Briefly reviews the literature on coping and the results of a survey of Australian…

  14. Reliability and Usefulness of Linear Sprint Testing in Adolescent Rugby Union and League Players.

    PubMed

    Darrall-Jones, Joshua D; Jones, Ben; Roe, Gregory; Till, Kevin

    2016-05-01

    Darrall-Jones, JD, Jones, B, Roe, G, and Till, K. Reliability and usefulness of linear sprint testing in adolescent rugby union and league players. J Strength Cond Res 30(5): 1359-1364, 2016-The purpose of this study was to evaluate (a) whether there were differences in sprint times at 5, 10, 20, 30, and 40 m between rugby union and rugby league players, (b) determine the reliability and usefulness of linear sprint testing in adolescent rugby players. Data were collected on 28 rugby union and league academy players over 2 testing sessions, with 3-day rest between sessions. Rugby league players were faster at 5 m than rugby union players, with further difference unclear. Sprint time at 10, 20, 30, and 40 m was all reliable (coefficient of variation [CV] = 3.1, 1.8, 2.0, and 1.3%) but greater than the smallest worthwhile change (SWC [0.2 × between-subject SD]), rating the test as marginal for usefulness. Although the test was incapable of detecting the SWC, we recommend that practitioners and researchers use Hopkins' proposed method; whereby plotting the change score of the individual at each split (±typical error [TE] expressed as a CV) against the SWC and visually inspecting whether the TE crosses into the SWC are capable of identifying whether a change is both real (greater than the noise of the test, i.e., >TE) and of practical significance (>SWC). Researchers and practitioners can use the TE and SWC from this study to assess changes in performance of adolescent rugby players when using single beam timing gates. PMID:26466131

  15. Drugs of abuse and the adolescent athlete

    PubMed Central

    2010-01-01

    Doping with endocrine drugs is quite prevalent in amateur and professional athletes. The World Anti-Doping Agency (WADA) has a list of banned drugs for athletes who compete and a strategy to detect such drugs. Some are relatively easy, anabolic steroids and erythropoietin, and others more difficult, human growth hormone (rhGH) and insulin like growth factor I (IGF-I). The use of such compounds is likely less in adolescent athletes, but the detection that much more difficult given that the baseline secretion of the endogenous hormone is shifting during pubertal development with the greatest rise in testosterone in boys occuring about the time of peak height velocity and maximal secretion of hGH and IGF-I. This review notes the rationale, physiology, performance enhancement, adverse events and the detection of doping with insulin, rhGH, rhIGF-I, erythropoietin, and anabolic-androgenic steroids. PMID:20167068

  16. Rhabdomyolysis in adolescent athletes: review of cases.

    PubMed

    Hummel, Kevin; Gregory, Andrew; Desai, Neerav; Diamond, Alex

    2016-05-01

    Rhabdomyolysis is a syndrome characterized by muscle pain, weakness and myoglobinuria and ranges in severity from asymptomatic to life threatening with acute kidney failure. While a common condition in adult populations, it is understudied in pediatrics and the majority of adolescent cases are likely exercise-induced, caused by strenuous exercise in athletes. Recently, in our pediatric sports medicine practice, we have seen numerous cases of late adolescent high school athletes who present with severe muscle pain and were found to have elevated creatine kinase levels. The cases review potential contributing factors including characteristics of the workout, use of supplements, caffeine, medication, and metabolic or genetic predisposition. Treatment for exercised-induced rhabdomyolysis rarely requires more than rehydration. Return to play should be progressive, individualized, and include acclimatization and monitoring of hydration status, though guidelines require further review. PMID:27031535

  17. Two types of laminolysis in adolescent athletes.

    PubMed

    Miyagi, Ryo; Sairyo, Koichi; Sakai, Toshinori; Yoshioka, Hiroshi; Yasui, Natsuo; Dezawa, Akira

    2012-12-01

    Bony defects in the spine are divided into three main types: spondylolysis, pediculolysis, and laminolysis. Lumbar spondylolysis is a well-known stress fracture that occurs frequently in adolescent athletes. Pediculolysis means stress fracture of the pedicle, which sometimes occurs subsequent to unilateral spondylolysis. Laminolysis is a rarely reported stress fracture similar to spondylolysis and pediculolysis that sometimes causes low back pain (LBP). However, its pathomechanism has not been elucidated. Recently, we encountered four adolescent athletes with symptomatic laminolysis. Mean age was 15.8 (range 15-17) years. All subjects reported severe LBP exacerbated by extension of the lumbar spine, and radiology revealed two types of laminolysis: hemilaminar type and intralaminar type. To elucidate the mechanisms of each type, we reviewed a biomechanical study, and found that the hemilaminar type was thought to be subsequent to contralateral spondylolysis, while the intralaminar type might be a result of a stress fracture due to repetitive extension loading. PMID:22815057

  18. Functional anatomy and muscle moment arms of the pelvic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris).

    PubMed

    Williams, S B; Wilson, A M; Rhodes, L; Andrews, J; Payne, R C

    2008-10-01

    We provide quantitative anatomical data on the muscle-tendon architecture and geometry of the pelvic limb of an elite sprint athlete, the racing greyhound. Specifically, muscle masses, muscle lengths, fascicle lengths, pennation angles and muscle moment arms were measured. Maximum isometric force and power of muscles, the maximum muscle torque at joints and tendon stress and strain were estimated. We compare data with that published for a generalized breed of canid, and other cursorial mammals such as the horse and hare. The pelvic limb of the racing greyhound had a relatively large volume of hip extensor muscle, which is likely to be required for power production. Per unit body mass, some pelvic limb muscles were relatively larger than those in less specialized canines, and many hip extensor muscles had longer fascicle lengths. It was estimated that substantial extensor moments could be created about the tarsus and hip of the greyhound allowing high power output and potential for rapid acceleration. The racing greyhound hence possesses substantial specializations for enhanced sprint performance. PMID:18657259

  19. Relationships between anthropometric measures and athletic performance, with special reference to repeated-sprint ability, in the Qatar national soccer team.

    PubMed

    Brocherie, Franck; Girard, Olivier; Forchino, Fabricio; Al Haddad, Hani; Dos Santos, Gilvan A; Millet, Grégoire P

    2014-01-01

    The aim of this study was to determine potential relationships between anthropometric parameters and athletic performance with special consideration to repeated-sprint ability (RSA). Sixteen players of the senior male Qatar national soccer team performed a series of anthropometric and physical tests including countermovement jumps without (CMJ) and with free arms (CMJwA), straight-line 20 m sprint, RSA (6 × 35 m with 10 s recovery) and incremental field test. Significant (P < 0.05) relationships occurred between muscle-to-bone ratio and both CMJs height (r ranging from 0.56 to 0.69) as well as with all RSA-related variables (r < -0.53 for sprinting times and r = 0.54 for maximal sprinting speed) with the exception of the sprint decrement score (Sdec). The sum of six skinfolds and adipose mass index were largely correlated with Sdec (r = 0.68, P < 0.01 and r = 0.55, P < 0.05, respectively) but not with total time (TT, r = 0.44 and 0.33, P > 0.05, respectively) or any standard athletic tests. Multiple regression analyses indicated that muscular cross-sectional area for mid-thigh, adipose index, straight-line 20 m time, maximal sprinting speed and CMJwA are the strongest predictors of Sdec (r(2) = 0.89) and TT (r(2) = 0.95) during our RSA test. In the Qatar national soccer team, players' power-related qualities and RSA are associated with a high muscular profile and a low adiposity. This supports the relevance of explosive power for the soccer players and the larger importance of neuromuscular qualities determining the RSA. PMID:24742185

  20. Adolescent idiopathic scoliosis in athletes: is there a connection?

    PubMed

    Kenanidis, Eustathios I; Potoupnis, Michael E; Papavasiliou, Kyriakos A; Sayegh, Fares E; Kapetanos, George A

    2010-06-01

    The potential relationship between adolescent idiopathic scoliosis (AIS) and sports is rather vague. Sports have often been considered to be a causative factor of, or a treatment option for the former, particularly among adolescent athletes who are engaged in certain athletic activities. The highly repetitive nature of sports, amenorrhea, exercise-related exerted stress on the immature spine of professional adolescent athletes, and the joint laxity that may coexist during adolescence, have also been associated with an increased incidence of AIS. The purpose of this article is to discuss the potential connection between sports and AIS by reviewing the existing literature. PMID:20631476

  1. Clinical examination, spondylolysis and adolescent athletes.

    PubMed

    Sundell, C-G; Jonsson, H; Ådin, L; Larsén, K H

    2013-03-01

    Symptomatic spondylolysis is a stress reaction caused by microtrauma during physical exercise, an imaging diagnostic subgroup of Adolescent Low Back Pain (ALBP), found in adolescent athletes. Early diagnosis increases the possibility of healing. Thus, it is important to divide ALBP into subgroups. The aim of this study was to evaluate clinical tests that can distinguish symptomatic spondylolysis from other forms of ALBP in order to facilitate early referral for diagnostic imaging. The investigation subjects were a prospective case series with a control group, 25 subjects with ALBP and 13 subjects that had no history of LBP. The 2 groups were examined using the same clinical protocol. MRI of the whole lumbar spine was performed in both the case and control groups and CT investigations of the L4 and L5 vertebrae were performed in the case group. Significant differences between the 2 groups were found in 8 of our clinical tests. No clinical test, alone or in combination, could distinguish between spondylolysis and other forms of ALBP. As 88% of the subjects in the case group had MRI findings and almost 50% had spondylolysis, MRI should be performed at an early age in young athletes with ALBP. PMID:23027361

  2. Rotator cuff injuries in adolescent athletes.

    PubMed

    Weiss, Jennifer M; Arkader, Alexandre; Wells, Lawrence M; Ganley, Theodore J

    2013-03-01

    The cause of rotator cuff injuries in the young athlete has been described as an overuse injury related to internal impingement. Abduction coupled with external rotation is believed to impinge on the rotator cuff, specifically the supraspinatus, and lead to undersurface tears that can progress to full-thickness tears. This impingement is believed to be worsened with increased range of motion and instability in overhead athletes. A retrospective review of seven patients diagnosed with rotator cuff injuries was performed to better understand this shoulder injury pattern. The type of sport played, a history of trauma, diagnosis, treatment method, and outcome were noted. Six patients were male and one was a female. Baseball was the primary sport for four patients, basketball for one, gymnastics for one, and wrestling for one. The following injury patterns were observed: two patients tore their subscapularis tendon, two sustained avulsion fractures of their lesser tuberosity, one tore his rotator interval, one tore his supraspinatus, and one avulsed his greater tuberosity. Only four patients recalled a specific traumatic event. Three patients were treated with arthroscopic rotator cuff repair, three with miniopen repair, and one was treated with rehabilitation. Six of the seven patients returned to their preinjury level of sport after treatment. Rotator cuff tears are rare in the adolescent age group. The injury patterns suggest that acute trauma likely accounts for many rotator cuff tears and their equivalents in the young patient. Adolescents with rotator cuff tears reliably return to sports after treatment. The possibility of rotator cuff tears in skeletally immature athletes should be considered. The prognosis is very good once this injury is identified and treated. PMID:22668571

  3. Accuracy of predictive equations for resting metabolic rate in Korean athletic and non-athletic adolescents

    PubMed Central

    Kim, Jae-Hee; Kim, Myung-Hee; Kim, Gwi-Sun; Park, Ji-Sun

    2015-01-01

    BACKGROUND/OBJECTIVES Athletes generally desire changes in body composition in order to enhance their athletic performance. Often, athletes will practice chronic energy restrictions to attain body composition changes, altering their energy needs. Prediction of resting metabolic rates (RMR) is important in helping to determine an athlete's energy expenditure. This study compared measured RMR of athletic and non-athletic adolescents with predicted RMR from commonly used prediction equations to identify the most accurate equation applicable for adolescent athletes. SUBJECTS/METHODS A total of 50 athletes (mean age of 16.6 ± 1.0 years, 30 males and 20 females) and 50 non-athletes (mean age of 16.5 ± 0.5 years, 30 males and 20 females) were enrolled in the study. The RMR of subjects was measured using indirect calorimetry. The accuracy of 11 RMR prediction equations was evaluated for bias, Pearson's correlation coefficient, and Bland-Altman analysis. RESULTS Until more accurate prediction equations are developed, our findings recommend using the formulas by Cunningham (-29.8 kcal/day, limits of agreement -318.7 and +259.1 kcal/day) and Park (-0.842 kcal/day, limits of agreement -198.9 and +196.9 kcal/day) for prediction of RMR when studying male adolescent athletes. Among the new prediction formulas reviewed, the formula included in the fat-free mass as a variable [RMR = 730.4 + 15 × fat-free mass] is paramount when examining athletes. CONCLUSIONS The RMR prediction equation developed in this study is better in assessing the resting metabolic rate of Korean athletic adolescents. PMID:26244075

  4. Bone Health in Adolescent Athletes with a Focus on Female Athlete Triad

    PubMed Central

    Ackerman, Kathryn E.; Misra, Madhusmita

    2013-01-01

    Peak bone mass (PBM) is a negative predictor of osteoporosis and life-long fracture risk. Because osteoporosis is such a prevalent disease with life-threatening consequences later in life, it is important to try to maximize PBM. Adolescence is a critical time for bone acquisition. This review discusses some of the differences in male and female skeletal development and modifiable factors that enhance bone accrual in this age group, particularly in athletes. Hormonal influences, physical activity effects, and nutritional contributions are presented, with a focus on the adolescent athlete. Emphasis is placed on the importance of appropriate energy availability in this age group. The Female Athlete Triad (the inter-relationship of decreased energy availability, menstrual irregularity, and low bone density) is an important issue for adolescent, athletic women, and is therefore reviewed, including prevention and treatment strategies. Recommendations for maximizing bone density in both male and female adolescents are discussed. PMID:21378496

  5. Effects of acute supplementation of L-arginine and nitrate on endurance and sprint performance in elite athletes.

    PubMed

    Sandbakk, Silvana Bucher; Sandbakk, Øyvind; Peacock, Oliver; James, Philip; Welde, Boye; Stokes, Keith; Böhlke, Nikolai; Tjønna, Arnt Erik

    2015-08-01

    This study examined the effects of acute supplementation with L-arginine and nitrate on running economy, endurance and sprint performance in endurance-trained athletes. In a randomised cross-over, double-blinded design we compared the effects of combined supplementation with 6 g L-arginine and 614 mg nitrate against 614 mg nitrate alone and placebo in nine male elite cross-country skiers (age 18 ± 0 years, VO2max 69.3 ± 5.8 ml ⋅ min(-1) ⋅ kg(-1)). After a 48-hour standardisation of nutrition and exercise the athletes were tested for plasma nitrate and nitrite concentrations, blood pressure, submaximal running economy at 10 km ⋅ h(-1) and 14 km ⋅ h(-1) at 1% incline and 180 m as well as 5-km time-trial running performances. Plasma nitrite concentration following L-arginine + nitrate supplementation (319 ± 54 nmol ⋅ L(-1)) did not differ from nitrate alone (328 ± 107 nmol ⋅ L(-1)), and both were higher than placebo (149 ± 64 nmol ⋅ L(-1), p < 0.01). There were no differences in physiological responses during submaximal running or in 5-km performance between treatments. The plasma nitrite concentrations indicate greater nitric oxide availability both following acute supplementation of L-arginine + nitrate and with nitrate alone compared to placebo, but no additional effect was revealed when L-arginine was added to nitrate. Still, there were no effects of supplementation on exercise economy or endurance running performance in endurance-trained cross-country skiers. PMID:25445632

  6. Predicting the Sprint Performance of Adolescent Track Cyclists Using the 3-Minute All-out Test.

    PubMed

    Waldron, Mark; Gray, Adrian; Furlan, Nicola; Murphy, Aron

    2016-08-01

    Waldron, M, Gray, A, Furlan, N, and Murphy, A. Predicting the sprint performance of adolescent track cyclists using the 3-minute all-out test. J Strength Cond Res 30(8): 2299-2306, 2016-This study aimed to predict 500-m time trial (TT) and 2,000-m pursuit speed of adolescent cyclists (age range = 13-15 years) using mechanical parameters derived from a critical power (CP) test and anthropometric variables. Ten well-trained competitive cyclists were assessed for body composition, body mass, stature, and frontal surface area (FSA), as well as completing the CP test. The personal best speed (km·h) of each rider during competition in 500-m TT and 2,000-m pursuit races was predicted based on the CP test data and anthropometric profiles using multiple regression analysis. A combination of the CP·FSA and internal (predicted) to external work ratio performed by the cyclists (Wint:Wext) predicted 500-m TT speed (R = 0.97; standard error of the estimate (SEE) = 0.82, P ≤ 0.001), whereas a combination of mean power·FSA (mean power) and body fat percentage predicted 2,000-m pursuit speed (R = 0.90; SEE = 1.5, p < 0.001). Between 90 and 97% of the variance in the sprint performance of adolescent cyclists can be explained by mechanical and anthropometric parameters, derived from a single visit to the laboratory. The tests and equations provided can be adopted by coaches to predict performance and set appropriate training intensities. PMID:26694504

  7. URINARY CREATINE AT REST AND AFTER REPEATED SPRINTS IN ATHLETES: A PILOT STUDY

    PubMed Central

    Nasrallah, F.; Feki, M.; Chamari, K.; Omar, S.; Alouane-Trabelsi, L.; Ben Mansour, A.; Kaabachi, N.

    2014-01-01

    Creatine plays a key role in muscle function and its evaluation is important in athletes. In this study, urinary creatine concentration was measured in order to highlight its possible significance in monitoring sprinters. The study included 51 sprinters and 25 age- and sex-matched untrained subjects as a control group. Body composition was measured and dietary intake estimated. Urine samples were collected before and after standardized physical exercise. Creatine was assessed by gas chromatography mass spectrometry. Basal urinary creatine (UC) was significantly lower in sprinters than controls (34±30 vs. 74±3 µmol/mmol creatinine, p < 0.05). UC was inversely correlated with body mass (r = −0.34, p < 0.01) and lean mass (r = −0.30, p < 0.05), and positively correlated with fat mass (r = 0.32, p < 0.05). After acute exercise, urinary creatine significantly decreased in both athletes and controls. UC is low in sprinters at rest and further decreases after exercise, most likely due to a high uptake and use of creatine by muscles, as muscle mass and physical activity are supposed to be greater in athletes than untrained subjects. Further studies are needed to test the value of urinary creatine as a non-invasive marker of physical condition and as a parameter for managing Cr supplementation in athletes. PMID:24917689

  8. Coaching Strategies for Helping Adolescent Athletes Cope with Stress

    ERIC Educational Resources Information Center

    Gilbert, Jenelle N.; Gilbert, Wade; Morawski, Cynthia

    2007-01-01

    This article discusses the various sources of athlete stress and the strategies that coaches can use to help young athletes cope with it. The information is based on a study with a competitive adolescent soccer team and its two coaches, and a review of the coaching and sport psychology literature. The suggested coaching strategies can help to…

  9. Risk Factors for Eating Disorders among Male Adolescent Athletes

    PubMed Central

    PUSTIVŠEK, Suzana; HADŽIĆ, Vedran; DERVIŠEVIĆ, Edvin

    2015-01-01

    Objective Eating disorders (ED) are an important and increasing problem in adolescents. The objective of this study was to examine the risk factors and the prevalence of risk for ED among male adolescent elite athletes and nonathletic controls. Differences between male athletes competing in aerobic, anaerobic and aerobic-anaerobic sports were examined as well. Methods This was a cross-sectional epidemiological study. A cross-sectional questionnaire survey and anthropometric measurements were conducted on 351 adolescents (athletes n = 228; controls n = 123). All participants were aged 15–17 at the time of measuring. Risk for ED was determined using a SCOFF questionnaire. Results The overall prevalence of the risk for ED in male adolescents was 24.8%, with no significant differences among athletes and controls or different subgroups of athletes (p>0.05), although the highest prevalence (37.2%) was registered in aerobic subgroup of athletes. Higher number of attempts to lose weight was associated with increased risk of ED in each group (athletes and controls). Other predictors referred to lack of breakfast and body composition in aerobic subgroup of athletes and number of meals and training frequency in anaerobic subgroup. The most common reasons for dieting were improvement of sport results (19.6–44.2%) and better self-esteem (41.5%) in athletes and controls respectively. Conclusions Participation in the competitive sport itself is not associated with the increased risk for ED. It seems that risk factors for ED for adolescent athletes competing in aerobic and anaerobic sports represent a subject that deserves consideration and further investigation in the future.

  10. Shoulder and elbow injuries in the adolescent athlete.

    PubMed

    Krabak, Brian J; Alexander, Eric; Henning, Troy

    2008-05-01

    The shoulder and elbow represent two of the most commonly injured joints in the adolescent population. Specific injuries vary by sport and can involve various structures, depending on the mechanism of injury. Unlike the adult shoulder, the immature skeletal structure of the adolescent athlete can lead to several unique injuries. By understanding the special demands placed on the immature shoulder, the sports physician can more effectively treat the resultant injury. This article reviews the diagnosis and management of unique injuries to the shoulder and elbow in the adolescent athlete. PMID:18395648

  11. Surgical Treatment of Clavicle Fractures in the Adolescent Athlete

    PubMed Central

    Fanter, Nathan J.; Kenny, Ryan M.; Baker, Champ L.; Baker, Champ L.

    2015-01-01

    Context: Current literature has clearly shown that the indications for surgical treatment of clavicle fractures in adults are expanding. Although clavicle fractures in children and adolescents have traditionally been treated nonoperatively, surgical treatment of displaced clavicle fractures may be indicated for adolescent athletes. Evidence Acquisition: A review of relevant articles published between 1970 and 2013 was completed using MEDLINE and the terms clavicle fracture and adolescent athlete. Study Design: Clinical review. Level of Evidence: Level 3. Results: Excellent outcomes and rapid return to competition can be achieved with surgical management of displaced clavicle fractures in the adolescent athlete with high functional demands similar to those of their adult counterparts. Complications include hardware irritation, screw loosening, pin migration, peri-incisional numbness, and refracture. Athletes and families must be counseled regarding complications and potential need for secondary surgery to remove hardware. Conclusion: The adolescent athlete with a displaced, shortened, or comminuted clavicle fracture presents a unique, controversial dilemma for the surgeon. Earlier return to competition can be achieved with surgical management to restore length and alignment and may prevent malunion, nonunion, and poor outcomes. PMID:25984259

  12. Creatine and the Male Adolescent Athlete

    ERIC Educational Resources Information Center

    Schumaker, Shauna; Eyers, Christina; Cappaert, Thomas

    2012-01-01

    As the level of competition in youth sports increases, so does athletes' vulnerability to experimenting with performance-enhancing aids (PEAs) at alarmingly young ages. One of the more commonly used PEAs is a supplement called creatine, which has the ability to generate muscular energy, allowing athletes to train at higher intensities for longer…

  13. Self-Esteem of Adolescent Athletes.

    ERIC Educational Resources Information Center

    Lee, Annette L.

    While self-esteem develops after life's primary needs have been satisfied, other factors can influence its development. This thesis investigates the self-esteem of high school and college athletes. The independent variables investigated were gender, athletic participation, family structure, and reported grades. The dependent variables were the…

  14. Gratitude and Adolescent Athletes' Well-Being

    ERIC Educational Resources Information Center

    Chen, Lung Hung; Kee, Ying Hwa

    2008-01-01

    Two cross-sectional studies were conducted to examine the relationships between gratitude and athletes' well-being. Study 1 examines the relationship between dispositional gratitude and well-being, while Study 2 investigates the relationship between sport-domain gratitude and well-being. In Study 1, 169 Taiwanese senior high school athletes (M =…

  15. Adolescent aesthetic athletes: a group at risk for eating pathology?

    PubMed

    Van Durme, Kim; Goossens, Lien; Braet, Caroline

    2012-04-01

    Previous research shows that leanness- and weight-dependent sports increase the risk of developing disturbed eating behaviour. This study investigated whether adolescent aesthetic athletes (n=68, M=14.6 years), particularly ballet dancers and figure skaters, exhibit more eating pathology compared to the general population. Furthermore, it was investigated whether sport-related factors have explanatory value for the dieting behaviour of aesthetic athletes. To asses eating pathology, reliable and valid self-report questionnaires were used including the Eating Disorder Inventory-II, the Children's Eating Disorder Examination-Questionnaire and the Dutch Eating Behaviour Questionnaire. Results show that female aesthetic athletes show more drive for thinness, features of bulimia, dieting behaviour and concerns about weight and shape compared to female adolescents from the general population. Concerning the explanation of dieting behaviour in aesthetic athletes, both sport-related factors (competition state anxiety) and general risk factors (eating concern) seem to be relevant. These results suggest that female aesthetic athletes show more disturbed eating behaviour and thoughts than female adolescents from the general population and therefore may have an enhanced risk of developing clinical eating disorders. PMID:22365793

  16. Physiological, biomechanical and anthropometrical predictors of sprint swimming performance in adolescent swimmers.

    PubMed

    Lätt, Evelin; Jürimäe, Jaak; Mäestu, Jarek; Purge, Priit; Rämson, Raul; Haljaste, Kaja; Keskinen, Kari L; Rodriguez, Ferran A; Jürimäe, Toivo

    2010-01-01

    The purpose of this study was to analyze the relationships between 100-m front crawl swimming performance and relevant biomechanical, anthropometrical and physiological parameters in male adolescent swimmers. Twenty five male swimmers (mean ± SD: age 15. 2 ± 1.9 years; height 1.76 ± 0.09 m; body mass 63.3 ± 10.9 kg) performed an all-out 100-m front crawl swimming test in a 25-m pool. A respiratory snorkel and valve system with low hydrodynamic resistance was used to collect expired air. Oxygen uptake was measured breath-by-breath by a portable metabolic cart. Swimming velocity, stroke rate (SR), stroke length and stroke index (SI) were assessed during the test by time video analysis. Blood samples for lactate measurement were taken from the fingertip pre exercise and at the third and fifth minute of recovery to estimate net blood lactate accumulation (ΔLa). The energy cost of swimming was estimated from oxygen uptake and blood lactate energy equivalent values. Basic anthropometry included body height, body mass and arm span. Body composition parameters were measured using dual-energy X-ray absorptiometry (DXA). Results indicate that biomechanical factors (90.3%) explained most of 100-m front crawl swimming performance variability in these adolescent male swimmers, followed by anthropometrical (45.8%) and physiological (45.2%) parameters. SI was the best single predictor of performance, while arm span and ∆La were the best anthropometrical and physiological indicators, respectively. SI and SR alone explained 92.6% of the variance in competitive performance. These results confirm the importance of considering specific stroke technical parameters when predicting success in young swimmers. Key pointsThis study investigated the influence of different anthropometrical, physiological and biomechanical parameters on 100-m swimming performance in adolescent boys.Biomechanical factors contributed most to sprint swimming performance in these young male swimmers (90

  17. Physiological, Biomechanical and Anthropometrical Predictors of Sprint Swimming Performance in Adolescent Swimmers

    PubMed Central

    Lätt, Evelin; Jürimäe, Jaak; Mäestu, Jarek; Purge, Priit; Rämson, Raul; Haljaste, Kaja; Keskinen, Kari L.; Rodriguez, Ferran A.; Jürimäe, Toivo

    2010-01-01

    The purpose of this study was to analyze the relationships between 100-m front crawl swimming performance and relevant biomechanical, anthropometrical and physiological parameters in male adolescent swimmers. Twenty five male swimmers (mean ± SD: age 15. 2 ± 1.9 years; height 1.76 ± 0.09 m; body mass 63.3 ± 10.9 kg) performed an all-out 100-m front crawl swimming test in a 25-m pool. A respiratory snorkel and valve system with low hydrodynamic resistance was used to collect expired air. Oxygen uptake was measured breath-by-breath by a portable metabolic cart. Swimming velocity, stroke rate (SR), stroke length and stroke index (SI) were assessed during the test by time video analysis. Blood samples for lactate measurement were taken from the fingertip pre exercise and at the third and fifth minute of recovery to estimate net blood lactate accumulation (ΔLa). The energy cost of swimming was estimated from oxygen uptake and blood lactate energy equivalent values. Basic anthropometry included body height, body mass and arm span. Body composition parameters were measured using dual-energy X-ray absorptiometry (DXA). Results indicate that biomechanical factors (90.3%) explained most of 100-m front crawl swimming performance variability in these adolescent male swimmers, followed by anthropometrical (45.8%) and physiological (45.2%) parameters. SI was the best single predictor of performance, while arm span and ∆La were the best anthropometrical and physiological indicators, respectively. SI and SR alone explained 92.6% of the variance in competitive performance. These results confirm the importance of considering specific stroke technical parameters when predicting success in young swimmers. Key points This study investigated the influence of different anthropometrical, physiological and biomechanical parameters on 100-m swimming performance in adolescent boys. Biomechanical factors contributed most to sprint swimming performance in these young male swimmers (90

  18. Common medial elbow injuries in the adolescent athlete.

    PubMed

    Leahy, Ian; Schorpion, Melissa; Ganley, Theodore

    2015-01-01

    Recently there has been increased year-round sports participation among children and adolescents with limited to no rest periods. This has led to increases in pediatric repetitive stress injuries, once considered a rarity. Whether in the throwing athlete or in the athlete that experiences repetitive axial loading; increased medial tension and overload syndromes can lead to stress reactions and fractures. This occurs in the developing athlete due to the bone being weaker than the surrounding tendons and ligaments. The medial elbow is a high stress area and is susceptible to many conditions including apophysitis , avulsion fractures and ulnar collateral ligament disruption. Valgus stress can cause injury to the medial elbow which can lead to increased lateral compression, Panner's disease and osteochondral lesions of the capitellum and olecranon. The purpose of this manuscript is to review common elbow disorders in the adolescent population, outline management and highlight important features of rehabilitation. PMID:25840494

  19. Contribution of Athletic Identity to Child and Adolescent Physical Activity

    PubMed Central

    Anderson, Cheryl B.; Mâsse, Louise C.; Zhang, Hong; Coleman, Karen J.; Chang, Shine

    2009-01-01

    Background Identity theorists maintain that domain-specific self-concepts help explain the differential investment of people’s time and effort in various activities. Purpose This study examined the contribution of athletic identity and three key demographic variables to physical activity and sports team participation. Methods Students in Grades 4–5 (n=391, mean age 9.9 years, range 8–13 years, collected in 2003) and Grades 7–8 (n=948, mean age 13.6 years, range 11–15 years, collected in 2002 and 2006) completed the 40-item Athletic Identity Questionnaire, which measures self-perceptions of athletic appearance; competence; importance of physical activity and sports; and encouragement for activity from parents, teachers, and friends. Hierarchic multiple regression analyses in 2008 assessed the effects of athletic identity, race/ethnicity group, gender, and overweight status on 7-day moderate-to-vigorous physical activity (MVPA) and organized sport team participation in each age group. Results In children and adolescents, the global score of athletic identity was independently, positively related to MVPA (p<0.0001, p<0.0001, respectively) and team participation (p<0.0001, p<0.0001, respectively), after controlling for demographic variables. More variance in MVPA was explained in children (23%) than in adolescents (5%), in contrast to team sports (5% in children, 15% in adolescents). In the subscale analyses, positive relationships for appearance, competence, importance, and parental encouragement persisted independent of demographic factors. Conclusions Results support the role of athletic self-concept in promoting physical activity and organized sport participation in children and adolescents. PMID:19595559

  20. Weight cycling in adolescent Taekwondo athletes

    PubMed Central

    Kazemi, Mohsen; Rahman, Alima; De Ciantis, Marco

    2011-01-01

    Background Weight reduction cycles are used by weight classed athletes in Taekwondo to make a weight category. Tension, dizziness, headaches, and confusion have been associated with rapid weight loss (RWL). There is a lack of research in weight cycling and its benefits among Taekwondo athletes. Purpose To investigate the rate of weight cycling in Junior Taekwondo athletes and its effect on performance. Methods Athletes were weighed prior to competition, then again before their first match. Body mass difference in relation to winning was compared. Results A significant increase from weigh-in to pre-match measurements was consistently found in both genders with no significant difference between them. Winners had a mean body mass gain (1.02 kg) which was non-significantly less than the non-winners (1.09 kg). Conclusions RWL practices do not define which athlete will perform better. Negative effects of weight cycling coupled with RWL has unclear performance benefits which indicates a need for further research. PMID:22131569

  1. Ephedra Use in a Select Group of Adolescent Athletes

    PubMed Central

    P. Schaefer, Michael; Smith, Jay; L. Dahm, Diane; C. Sorenson, Matthew

    2006-01-01

    Ephedra-containing dietary supplements are consumed to improve sports performace, but may carry risks of cardiac and neurological adverse events. Little is known of their use by young athletes. Our aim was to determine the prevalence and patterns of ephedra use among high school athletes. An anonymous survey was performed in Rochester, Minnesota on high school athletes who participated in fall sports during 2003-04. Parental consent was obtained for athletes under age 18 years. Surveys were distributed at preparticipation examinations and in- school survey stations. The response rate to the survey was 68.2%, or 311 respondents out of a possible 456 with consent (or 26% of all 1197 athletes eligible prior to the consent process). Seven of 311 (2.3%) respondents used dietary supplements containing ephedra. Only one of seven users (14.3%) knew that the supplements they used contained ephedra. Ephedra use was more common in boys (five) than girls (two). Ephedra use was only found in 17 and 18-year-olds. The most common sports among ephedra users were football, track and field, and weightlifting. This study suggests that Ephedra use was infrequent among the young athletes in this population. However, ephedra users were generally unaware that the dietary supplements they consumed contained ephedra. Users were more likely to participate in football, track and field, and weightlifting. Ephedra users were likely to obtain supplements from their peers, and were largely uninformed of the content of their supplements. Key Points Ephedra is an herbal stimulant used as an ergogenic aide. Adolescent ephedra users most commonly obtain it from their friends. Adolescent athletes are likely to take ephedra unknowningly. PMID:24353458

  2. Adolescent elite athletes' cigarette smoking, use of snus, and alcohol.

    PubMed

    Martinsen, M; Sundgot-Borgen, J

    2014-04-01

    The purpose was to examine cigarette smoking, use of snus, alcohol, and performance-enhancing illicit drugs among adolescent elite athletes and controls, and possible gender and sport group differences. First-year students at 16 Norwegian Elite Sport High Schools (n = 677) and two randomly selected high schools (controls, n = 421) were invited to participate. Totally, 602 athletes (89%) and 354 (84%) controls completed the questionnaire. More controls than athletes were smoking, using snus, and drinking alcohol. Competing in team sports was associated with use of snus [odds ratio = 2.8, 95% confidence interval (CI) 1.6 to 4.7] and a similar percentage of male and female handball (22.2% vs 18.8%) and soccer players (15.7% vs 15.0%) reported using snus. For controls, not participating in organized sport was a predictor for smoking (odds ratio = 4.9, 95% CI 2.2 to 10.9). Female athletes were more prone to drink alcohol than males (46.3% vs 31.0%, P < 0.001). Only, 1.2% athletes and 2.8% controls reported use of performance-enhancing illicit drugs. In conclusion, use of legal drugs is less common among athletes, but this relationship depends on type of sport and competition level. The association between team sports and use of snus suggests that sport subcultures play a role. PMID:22830488

  3. The Athletic Trainer's Role in Modifying Nutritional Behaviors of Adolescent Athletes: Putting Theory into Practice

    PubMed Central

    Hackman, Robert M.; Katra, Jane E.; Geertsen, Susan M.

    1992-01-01

    Nutritional practices influence athletic performance and recovery from injury. The athletic trainer is ideally positioned to effect dietary changes with adolescent athletes—a group at high-risk for nutritional imbalances. Research shows that young adults generally do not change dietary practices when given factual nutrition and health information. This article provides a variety of behavior change strategies, based on models derived from health education and health psychology, which are likely to influence dietary choices. Promoting self-efficacy by enhancing perception of choice and control, peer modeling, cooperative support networks, goal-setting techniques, and behavioral self-monitoring may provide the motivational framework necessary to enhance dietary compliance. Dietary behavior change techniques are a valuable part of an athletic trainer's resources. PMID:16558172

  4. Effects of In-Water Passive Recovery on Sprint Swimming Performance and Heart Rate in Adolescent Swimmers

    PubMed Central

    Casuso, Rafael A.; Martínez-López, Emilio; Hita-Contreras, Fidel; Ruiz-Cazalilla, Irene; Cruz-Díaz, David; Martínez-Amat, Antonio

    2014-01-01

    The aim of the present study is to test the hypothesis that sprint swimming performance is enhanced by in-water passive recovery (IN) after sprint swimming bouts in well-trained adolescent swimmers. Using a randomized crossover study design, twelve well-trained adolescent swimmers performed two tests at the swimming pool after preliminary testing. They performed 5 bouts of 100m all-out swimming separated by 5 minutes of passive rest. Their individual in- or out-of-water passive recovery condition was randomized on the first day. In their second visit to the swimming pool the opposite recovery condition was indicated. More than 60% of the subjects which rested in-water were faster in the 5th bout when compared to the OUT group. However, no significant differences were found in blood lactate when IN and OUT were compared. After the first bout peak heart rate (HR peak) was lower in subsequent bouts for IN recovery when compared with OUT (p < 0.001). Thus, coaches and researchers should take into account that IN passive recovery may decrease loss of performance and diminish HR peak during sprint swimming bouts. This is particularly important given the use that many coaches give to HR as a tool in daily training. Key points In-water passive recovery minimizes the loss of performance during high intensity swimming Maximal HR is significantly reduced by in-water recovery Coaches should take this information into account when using HR to control swimming intensity Future research should study long-term effects induced by in-water passive recovery PMID:25435791

  5. Effect of a carbohydrate-protein multi-ingredient supplement on intermittent sprint performance and muscle damage in recreational athletes.

    PubMed

    Naclerio, Fernando; Larumbe-Zabala, Eneko; Cooper, Robert; Jimenez, Alfonso; Goss-Sampson, Mark

    2014-10-01

    Carbohydrate-protein-based multi-ingredient supplements have been proposed as an effective strategy for limiting the deleterious effects of exercise-induced muscle damage. This study compares the effects of a commercially available carbohydrate-protein supplement enriched with l-glutamine and l-carnitine-l-tartrate to carbohydrate alone or placebo on sprint performance, muscle damage markers, and recovery from intermittent exercise. On 3 occasions, 10 recreationally trained males ingested a multi-ingredient, a carbohydrate supplement, or a placebo before, during, and immediately after a 90-min intermittent repeated sprint test. Fifteen-metre sprint times, creatine kinase, myoglobin, and interleukin-6 were assessed before (pre), immediately after (post), 1 h after (1h), and 24 h after (24h) exercise. Total sprint time measured during the intermittent protocol was not different between conditions. Fifteen-metre sprint time was slower (p < 0.05) at post, 1h and 24h compared with pre without differences between conditions (p > 0.05). Creatine kinase at 24h was lower (p < 0.05) in the multi-ingredient (461.8 ± 271.8 U·L) compared with both carbohydrate and placebo (606 ± 314.5 U·L and 636 ± 344.6 U·L, respectively). Myoglobin increased (p < 0.05) in all 3 conditions at post and 1h compared with pre, showing lower values at 1h (p < 0.05) for the carbohydrate and a trend (p = 0.060) for multi-ingredient compared with the placebo condition (211.4 ± 127.2 ng·mL(-1) and 239.4 ± 103.8 ng·mL(-1) vs. 484.6 ± 200.0 ng·mL(-1), respectively). Interleukin-6 increased at both post and 1h compared with pre (p < 0.05) with no differences between conditions. In conclusion, ingesting a multi-ingredient supplement before, during, and immediately after a 90-min intermittent sprint test resulted in no effects on performance and fatigue while the accumulation of some biomarkers of muscle damage could be attenuated. PMID:25029675

  6. Body Mass-Related Predictors of the Female Athlete Triad Among Adolescent Athletes.

    PubMed

    Thralls, Katie J; Nichols, Jeanne F; Barrack, Michelle T; Kern, Mark; Rauh, Mitchell J

    2016-02-01

    Early detection of the female athlete triad is essential for the long-term health of adolescent female athletes. The purpose of this study was to assess relationships between common anthropometric markers (ideal body weight [IBW] via the Hamwi formula, youth-percentile body mass index [BMI], adult BMI categories, and body fat percentage [BF%]) and triad components, (low energy availability [EA], measured by dietary restraint [DR], menstrual dysfunction [MD], low bone mineral density [BMD]). In the sample (n = 320) of adolescent female athletes (age 15.9± 1.2 y), Spearman's rho correlations and multiple logistic regression analyses evaluated associations between anthropometric clinical cutoffs and triad components. All underweight categories for the anthropometric measures predicted greater likelihood of MD and low BMD. Athletes with an IBW >85% were nearly 4 times more likely to report MD (OR = 3.7, 95% CI [1.8, 7.9]) and had low BMD (OR = 4.1, 95% CI [1.2, 14.2]). Those in <5th percentile for their age-specific BMI were 9 times more likely to report MD (OR 9.1, 95% CI [1.8, 46.9]) and had low BMD than those in the 50th to 85th percentile. Athletes with a high BF% were almost 3 times more likely to report DR (OR = 2.8, 95% CI [1.4, 6.1]). Our study indicates that low age-adjusted BMI and low IBW may serve as evidence-based clinical indicators that may be practically evaluated in the field, predicting MD and low BMD in adolescents. These measures should be tested for their ability as tools to minimize the risk for the triad. PMID:26252427

  7. Tendon Adaptation to Sport-specific Loading in Adolescent Athletes.

    PubMed

    Cassel, M; Carlsohn, A; Fröhlich, K; John, M; Riegels, N; Mayer, F

    2016-02-01

    Tendon adaptation due to mechanical loading is controversially discussed. However, data concerning the development of tendon thickness in adolescent athletes is sparse. The purpose of this study was to examine possible differences in Achilles (AT) and patellar tendon (PT) thickness in adolescent athletes while considering age, gender and sport-specific loading. In 500 adolescent competitive athletes of 16 different sports and 40 recreational controls both ATs and PTs were sonographically measured. Subjects were divided into 2 age groups (< 13; ≥ 13 years) and 6 sport type categories (ball, combat, and water sports, combined disciplines, cycling, controls). In addition, 3 risk groups (low, moderate, high) were created according to the athlete's risk of developing tendinopathy. AT and PT thickness did not significantly differ between age groups (AT/PT:<13: 5.4±0.7 mm/3.6±0.5 mm;≥13: 5.3±0.7 mm/3.6±0.5 mm). In both age groups males presented higher tendon thickness than females (p<0.001). AT thickness was highest in ball sports/cyclists and lowest in controls (p≤0.002). PT thickness was greatest in water sports and lowest in controls (p=0.02). High risk athletes presented slightly higher AT thickness compared to the low risk group (p=0.03). Increased AT and PT thickness in certain sport types compared to controls supports the hypothesis of structural tendon adaptation due to sport-specific loading. PMID:26509367

  8. Rehabilitation programs and prevention strategies in adolescent throwing athletes.

    PubMed

    McFarland, Edward G; Ireland, Mary Lloyd

    2003-01-01

    A specific and early diagnosis must be made in the injured skeletally immature throwing athlete. A well-outlined program of rest, rehabilitation, and proper throwing techniques should be implemented and continued. Overuse injuries are preventable when biomechanics are sound and pitch counts are done with the limits enforced. Guidelines for inning limits, number of pitches, rest intervals, and throwing programs should be followed for adolescent pitchers because adolescents differ from adults. Information is included for specifications of the ball and helmet, as well as chest protective equipment. The goal should be for the Little League players to have fun and be injury free as they are competing, which gives them the best experience and allows continuation of athletic activities for a lifetime. PMID:12690839

  9. Cortical desmoids in adolescent top-level athletes

    PubMed Central

    Biedert, Roland M; Gal, Imre

    2015-01-01

    Two adolescent, highly active athletes are presented with unspecific symptoms of anterior knee pain. Conventional radiographs and magnetic resonance imaging (MRI) showed a suspicious but pathognomonic cortical irregularity of the dorsal, medial femoral condyle. Cortical desmoid is one of the most common incidental osseous findings on conventional radiographs and MRI of the knee. It often needs no follow-up examination in asymptomatic patients. Malignancy needs however to be ruled out. PMID:25992301

  10. Injuries about the hip in the adolescent athlete.

    PubMed

    Kovacevic, David; Mariscalco, Michael; Goodwin, Ryan C

    2011-03-01

    Athletic injuries in or around the hip in the adolescent athlete encompass possible causes such as a single, traumatic event to those of repetitive microtrauma. The injuries may involve the bone or the soft tissues, with former involving the epiphysis, apophysis, metaphysis, or diaphysis, whereas the latter includes muscles and tendons. With the improvements in surgical technique and instrumentation for hip arthroscopy and the development of magnetic resonance arthrography, clinicians have been able to diagnose and treat labral tears, hip instability, snapping hip, loose bodies, chondral injuries, and femoroacetabular impingement. The clinician needs to consider acquired conditions that may have coincidentally become apparent as a result of the adolescent's participation in an organized sports program. These include slipped capital femoral epiphysis, Legg-Calvé-Perthes disease, and pathologic lesions and fractures. This study reviews the more common acute and chronic overuse injuries in or around the hip in the adolescent athlete and discusses hip injury prevention in this active patient population. PMID:21293240

  11. Greater trochanter apophysitis in the adolescent athlete.

    PubMed

    Young, Simon W; Safran, Marc R

    2015-05-01

    Lower limb traction apophysitis is common in young athletes, occurring at sites such as the tibial tubercle (Osgood-Schlatter disease) and distal patella (Sinding-Larsen-Johansson disease). Around the hip, iliac apophysitis is well recognized, but no cases of greater trochanter apophysitis have previously been reported. We describe the case of a 15-year-old male basketball player with a 2-month history of the right hip pain and significant functional limitation. X-rays revealed widening of the greater trochanter apophysis with subchondral sclerosis, consistent with a diagnosis of traction apophysitis. The patient was treated with a period of relative rest and anti-inflammatory medication. He gradually returned to full athletic activity, including basketball, without recurrence of pain or limitation. We describe the first reported case of traction apophysitis of the greater trochanter. The unique muscular anatomy of this apophysis with balanced forces explains the rarity of this condition. If encountered, rest and activity modification is the recommended treatment. PMID:24942622

  12. Assessment of balance among adolescent track and field athletes.

    PubMed

    Knight, Adam C; Holmes, Megan E; Chander, Harish; Kimble, Amari; Stewart, Joshua Ty

    2016-06-01

    Track and field events place different demands on athletes and may have an effect on balance. This study investigated the effects of event specialty, gender, and leg dominance on balance among adolescent track and field athletes. Forty healthy adolescent track and field athletes (male = 23, female = 17) categorised into three different groups (sprinter = 20, distance runners = 13, throwers = 7) had their single leg static balance measured with the eyes open and the eyes closed using an AMTI force platform. Dependent variables included average displacement (cm) of the centre of pressure (COP) in the anterior/posterior direction and medial/lateral directions, the average velocity of the COP (cm/s) and the 95% ellipse area (cm(2)). Variables were analysed using a 3 (event specialty) × 2 (gender) × 2 (leg) ANOVA with repeated measures on the leg variable (p < 0.05). There was a significant difference (p < 0.05) in the average displacement of the COP in the medial/lateral direction for both the eyes open and closed condition, with the non-dominant leg demonstrating greater displacement than the dominant leg. This might increase the risk of injury for the non-dominant leg, but additional data should be collected and analysed on both dynamic balance and performance. PMID:27111401

  13. Factorial and construct validity of the athletic identity questionnaire for adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research describes the development of a measure of the general attribute of "athletic" in adolescents, encompassing exercise, sport, and physical activity. Based on a theoretical model supported in adults, the 40-item Athletic Identity Questionnaire (AIQ) for adolescents assesses four dimensio...

  14. Adaptation and validation of the athletic identity questionnaire-adolescent for use with children

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This article describes the adaptation of the Athletic Identity Questionnaire (AIQ) for Adolescents for use with children and evaluates its construct validity. Based on a theoretical model supported in adults and adolescents, the AIQ-Child measures the general attribute of athletic, which encompasses...

  15. [Banned performance enhancing ergogenic aids in children and adolescent athletes].

    PubMed

    Nemet, Dan; Eliakim, Alon

    2007-10-01

    Ergogenic aids (from the Greek, ergon, meaning work) are ingested to enhance energy utilization in athletes. In recent years there has been an increase in youth participating in competitive sports and, as a consequence, a concomitant increase in the usage of performance enhancing substances. Ergogenic aid usage could influence, or its efficiency could be influenced, during this period of rapid growth and sexual maturation, and by the marked hormonal fluctuations. Ephedra alkaloids; pain relief medications, diuretics, anabolic steroids and protein hormones are among the ergogenic aids used by young athletes. While there is no scientific evidence to support the usage of these agents for enhancing performance in children and adolescents, using supra-physiological doses may be associated with undesired side effects. PMID:17990397

  16. Effect of Different Sprint Training Methods on Sprint Performance Over Various Distances: A Brief Review.

    PubMed

    Rumpf, Michael C; Lockie, Robert G; Cronin, John B; Jalilvand, Farzad

    2016-06-01

    Rumpf, MC, Lockie, RG, Cronin, JB, and Jalilvand, F. Effect of different sprint training methods on sprint performance over various distances: a brief review. J Strength Cond Res 30(6): 1767-1785, 2016-Linear sprinting speed is an essential physical quality for many athletes. There are a number of different training modalities that can be used to improve sprint performance. Strength and conditioning coaches must select the most appropriate modalities for their athletes, taking into consideration the sprint distances that typically occur during competition. The study purpose was to perform a brief review as to the effect of specific (free sprinting; resisted sprinting by sleds, bands, or incline running; assisted sprinting with a towing device or a downhill slope), nonspecific (resistance and plyometric training), and combined (a combination of specific and nonspecific) training methods on different sprint distances (0-10, 0-20, 0-30, and 31+ m). A total of 48 studies fulfilled the inclusion criteria, resulting in 1,485 subjects from a range of athletic backgrounds. The training effects associated with specific sprint training were classified as moderate (effect size [ES] = -1.00; %change = -3.23). Generally, the effect of specific sprint training tended to decrease with distance, although the largest training effects were observed for the 31+ m distance. The greatest training effects (ES = -0.43; %change = -1.65) of nonspecific training were observed for the 31+ m distance. The combined training revealed greatest effects (ES = -0.59; %change = -2.81) for the 0-10 m distance. After this review, specific sprint training methods seem the most beneficial over the investigated distances. However, the implementation of nonspecific training methods (e.g., strength and power training) could also benefit speed and athletic performance. PMID:26492101

  17. Special considerations for adolescent athletic and asthmatic patients.

    PubMed

    Wuestenfeld, Jan C; Wolfarth, Bernd

    2013-01-01

    Asthma is defined as a chronic inflammatory disorder of the airways with bronchial hyperresponsiveness and variable bronchoconstriction, and is one of the most common diseases in childhood and adolescence. Exercise-induced asthma-like symptoms and asthma are also frequently seen in highly trained athletes. Exercise-induced asthma (EIA) and exercise-induced bronchoconstriction (EIB) are found in 8%-10% of healthy school-aged children and in 35% of children with asthma. Highly increased ventilation, inhalation of cold, dry air and air pollutants (eg, chlorine) are thought to be important triggers for EIA and EIB. EIA is often experienced concurrently with vocal cord dysfunction, which needs to be considered during the differential diagnosis. The pharmacological treatment of EIA is similar to the treatment of asthma in nonexercising adolescents. The therapy is based on anti-inflammatory drugs (eg, inhaled glucocorticosteroids) and bronchodilators (eg, β2-agonists). The treatment of EIB is comparable to the treatment of EIA and leukotriene modifiers offer a new and promising treatment option, particularly in EIB. Generally, athletes may not use β2-agonists according to the prohibited list of the World Anti-Doping Agency (WADA). However, the WADA list contains specific β2-agonistic substances that are permitted to be used by inhalation. PMID:24379703

  18. Special considerations for adolescent athletic and asthmatic patients

    PubMed Central

    Wuestenfeld, Jan C; Wolfarth, Bernd

    2013-01-01

    Asthma is defined as a chronic inflammatory disorder of the airways with bronchial hyperresponsiveness and variable bronchoconstriction, and is one of the most common diseases in childhood and adolescence. Exercise-induced asthma-like symptoms and asthma are also frequently seen in highly trained athletes. Exercise-induced asthma (EIA) and exercise-induced bronchoconstriction (EIB) are found in 8%–10% of healthy school-aged children and in 35% of children with asthma. Highly increased ventilation, inhalation of cold, dry air and air pollutants (eg, chlorine) are thought to be important triggers for EIA and EIB. EIA is often experienced concurrently with vocal cord dysfunction, which needs to be considered during the differential diagnosis. The pharmacological treatment of EIA is similar to the treatment of asthma in nonexercising adolescents. The therapy is based on anti-inflammatory drugs (eg, inhaled glucocorticosteroids) and bronchodilators (eg, β2-agonists). The treatment of EIB is comparable to the treatment of EIA and leukotriene modifiers offer a new and promising treatment option, particularly in EIB. Generally, athletes may not use β2-agonists according to the prohibited list of the World Anti-Doping Agency (WADA). However, the WADA list contains specific β2-agonistic substances that are permitted to be used by inhalation. PMID:24379703

  19. Dietary Intakes and Supplement Use in Pre-Adolescent and Adolescent Canadian Athletes.

    PubMed

    Parnell, Jill A; Wiens, Kristin P; Erdman, Kelly A

    2016-01-01

    Young athletes experience numerous dietary challenges including growth, training/competition, unhealthy food environments, and travel. The objective was to determine nutrient intakes and supplement use in pre-adolescent and adolescent Canadian athletes. Athletes (n = 187) aged 11-18 years completed an on-line 24-h food recall and dietary supplement questionnaire. Median energy intake (interquartile range) varied from 2159 kcal/day (1717-2437) in 11-13 years old females to 2905 kcal/day (2291-3483) in 14-18 years old males. Carbohydrate and protein intakes were 8.1 (6.1-10.5); 2.4 (1.6-3.4) in males 11-13 years, 5.7 (4.5-7.9); 2.0 (1.4-2.6) in females 11-13 years, 5.3 (4.3-7.4); 2.0 (1.5-2.4) in males 14-18 y and 4.9 (4.4-6.2); 1.7 (1.3-2.0) in females 14-18 years g/kg of body weight respectively. Median vitamin D intakes were below the recommended dietary allowance (RDA) and potassium was below the adequate intake (AI) for all athlete groups. Females 14-18 years had intakes below the RDA for iron 91% (72-112), folate 89% (61-114) and calcium 84% (48-106). Multivitamin-multiminerals, vitamin C, vitamin D, vitamin-enriched water, protein powder, sport foods, fatty acids, probiotics, and plant extracts were popular supplements. Canadian pre-adolescent and adolescent athletes could improve their dietary intakes by focusing on food sources of calcium, vitamin D, potassium, iron, and folate. With the exceptions of vitamin D and carbohydrates during long exercise sessions, supplementation is generally unnecessary. PMID:27571101

  20. Functional anatomy and muscle moment arms of the thoracic limb of an elite sprinting athlete: the racing greyhound (Canis familiaris).

    PubMed

    Williams, S B; Wilson, A M; Daynes, J; Peckham, K; Payne, R C

    2008-10-01

    We provide quantitative muscle-tendon architecture and geometry data for the racing greyhound thoracic limb. Muscle mass, belly length, fascicle lengths, pennation angles and moment arms were measured, as were tendon masses and lengths. Maximum isometric force and maximum power were estimated for muscles, and maximum stress and strain were estimated for tendons. Results are compared with other fast quadrupedal runners, and to previously published data in mixed-breed dogs. The implications of the functional adaptations of the greyhound thoracic limb for sprinting performance are discussed. The thoracic limb was found to benefit from a similar proportion of locomotor muscle mass to the pelvic limb, suggesting that it may be used to some extent in propulsion, or alternatively that stabilisation is very important in this animal. Extrinsic muscles, especially latissimus dorsi and pectoralis profundus, were predicted to be powerful and important for generating net positive work during accelerations. Proximal biarticular muscles show specialisation toward preventing collapse of the shoulder and elbow joints to enable strut-like limb function, or some form of dynamic control. Distal muscles did not appear specialised for elastic energy storage, a functional difference to pelvic limb muscles, and the equivalents in horse thoracic limbs. The greyhound thoracic limb appears to possess substantial differences from both that of more 'sub-maximal specialist' quadrupeds, and from the greyhound pelvic limb. PMID:19034998

  1. Sports Dietitians Australia position statement: sports nutrition for the adolescent athlete.

    PubMed

    Desbrow, Ben; McCormack, Joanna; Burke, Louise M; Cox, Gregory R; Fallon, Kieran; Hislop, Matthew; Logan, Ruth; Marino, Nello; Sawyer, Susan M; Shaw, Greg; Star, Anita; Vidgen, Helen; Leveritt, Michael

    2014-10-01

    It is the position of Sports Dietitians Australia (SDA) that adolescent athletes have unique nutritional requirements as a consequence of undertaking daily training and competition in addition to the demands of growth and development. As such, SDA established an expert multidisciplinary panel to undertake an independent review of the relevant scientific evidence and consulted with its professional members to develop sports nutrition recommendations for active and competitive adolescent athletes. The position of SDA is that dietary education and recommendations for these adolescent athletes should reinforce eating for long term health. More specifically, the adolescent athlete should be encouraged to moderate eating patterns to reflect daily exercise demands and provide a regular spread of high quality carbohydrate and protein sources over the day, especially in the period immediately after training. SDA recommends that consideration also be given to the dietary calcium, Vitamin D and iron intake of adolescent athletes due to the elevated risk of deficiency of these nutrients. To maintain optimal hydration, adolescent athletes should have access to fluids that are clean, cool and supplied in sufficient quantities before, during and after participation in sport. Finally, it is the position of SDA that nutrient needs should be met by core foods rather than supplements, as the recommendation of dietary supplements to developing athletes over-emphasizes their ability to manipulate performance in comparison with other training and dietary strategies. PMID:24668620

  2. Phase angle and bioelectrical impedance vectors in adolescent and adult male athletes.

    PubMed

    Koury, Josely C; Trugo N, M F; Torres, Alexandre G

    2014-09-01

    The aim of the current study was to assess phase angle (PA) and bioelectrical impedance vectors (BIVA) in adolescent (n = 105, 12-19 y) and adult (n = 90, 20-50 y) male athletes practicing varied sports modalities. Bioelectrical impedance analysis (BIA) was performed with a single-frequency tetrapolar impedance analyzer after the athletes had fasted overnight for 8 h. PA and BIVA were determined from BIA data. PA presented correlations (P < .01) with body-mass index (r = .58) in all athletes and also with age in adolescent (r = .63) and adult (r = -.27) athletes. Compared with adults, adolescent athletes presented lower PA and higher frequency of PA below the 5th percentile of a reference population (P < .001). The adolescents with low PA were mostly football and basketball players. The BIVA confidence ellipses of adult and adolescent athletes were different (P < .001) between them and from their respective reference populations and were closer than those of adult and adolescent nonathletes. About 80% of the athletes were in the 95th percentile of BIVA tolerance ellipses and in quadrants consistent with adequate body cell mass and total body water. The adolescent athletes outside the 95th percentile ellipse were all football and basketball players who showed indications of decreased water retention and body cell mass and of increased water retention, respectively. PA and BIVA ellipses showed that the intense training routine of the athletes changed functional and hydration parameters and that the magnitude of these changes in adolescents may depend on the sport modality practiced. PMID:24414089

  3. Influence of Strength, Sprint Running, and Combined Strength and Sprint Running Training on Short Sprint Performance in Young Adults.

    PubMed

    Marques, M C; Gabbett, T J; Marinho, D A; Blazevich, A J; Sousa, A; van den Tillaar, R; Izquierdo, M

    2015-10-01

    The purpose of this study was to assess the degree of transference of 6 weeks of full squat vs. full squat plus sprint running training to short (ranged from 0-10 to 0-30 m) sprint running performance in non-athletes. We hypothesized that a speed-full-squat training regimen could enhance squat strength and power with simultaneous improvements in short sprint performance. 122 physically active adults (age: 20.5±2.5 years; body mass: 65.8±6.1 kg; height: 1.71±0.08 m) were randomly divided into 4 groups: full squat training (n=36), combined full squat and sprint training (n=32), speed training only (n=34) and non-training control group (n=20). Each training group completed 2 sessions per week over 6 weeks, while the control group performed only their normal physical activity. Sprint performance was improved after sprint running or full squat training alone (1.7% and 1.8% P<0.05, respectively), however larger enhancements (2.3%; P<0.01) were observed after the combined full squat plus sprint training intervention. These results suggest that in recreationally active adults, combined full squat and sprint training provides a greater stimulus for improving sprint performance than either modality alone. PMID:25958946

  4. Sprint interval training (SIT) is an effective method to maintain cardiorespiratory fitness (CRF) and glucose homeostasis in Scottish adolescents

    PubMed Central

    Martin, R; Baker, JS; Young, J; Sculthorpe, N; Grace, FM

    2015-01-01

    The present study examined the physiological impact of a school based sprint interval training (SIT) intervention in replacement of standard physical education (SPE) class on cardio-respiratory fitness (CRF) and glucose homeostasis during the semester following summer vacation. Participants (n=49) were randomly allocated to either intervention (SIT; n=26, aged 16.9 ± 0.3 yrs) or control group who underwent standard physical education (SPE; n=23, aged 16.8 ± 0.6 yrs). CRF (VO2max) and glucose homeostasis were obtained prior-to and following 7 weeks of SIT exercise. Significant group x time interaction was observed for CRF (P < 0.01) with non-significant trends for fasting insulin (P= 0.08), and HOMA-IR (P=0.06). CRF decreased (P < 0.01) in SPE such that POST intervention CRF was significantly lower (P< 0.05) in SPE. Fasting plasma glucose (P < 0.01), insulin (P< 0.01) and HOMA-IR (P< 0.01) increased significantly amongst SPE. The main finding of the present study is that 7-weeks of SIT exercise is an effective method of maintaining (but not improving) CRF and fasting insulin homeostasis amongst school-going adolescents. SIT exercise demonstrates potential as a time efficient physiological adjunct to standard PE class in order to maintain CRF during the school term. PMID:26681833

  5. Motivational Cluster Profiles of Adolescent Athletes: An Examination of Differences in Physical-Self Perception

    PubMed Central

    Çağlar, Emine; Aşçı, F. Hülya

    2010-01-01

    The primary purpose of the present study was to identify motivational profiles of adolescent athletes using cluster analysis in non-Western culture. A second purpose was to examine relationships between physical self-perception differences of adolescent athletes and motivational profiles. One hundred and thirty six male (Mage = 17.46, SD = 1.25 years) and 80 female adolescent athletes (Mage = 17.61, SD = 1.19 years) from a variety of team sports including basketball, soccer, volleyball, and handball volunteered to participate in this study. The Sport Motivation Scale (SMS) and Physical Self-Perception Profile (PSPP) were administered to all participants. Hierarchical cluster analysis revealed a four-cluster solution for this sample: amotivated, low motivated, moderate motivated, and highly motivated. A 4 x 5 (Cluster x PSPP Subscales) MANOVA revealed no significant main effect of motivational clusters on physical self-perception levels (p > 0.05). As a result, findings of the present study showed that motivational types of the adolescent athletes constituted four different motivational clusters. Highly and moderate motivated athletes consistently scored higher than amotivated athletes on the perceived sport competence, physical condition, and physical self-worth subscales of PSPP. This study identified motivational profiles of competitive youth-sport participants. Key points Highly motivated athletes have a tendency to perceive themselves competent in psychomotor domains as compared to the amotivated athletes As the athletes feel more competent in psychomotor domain, they are more intrinsically motivated. The information about motivational profiles of adolescent athletes could be used for developing strategies and interventions designed to improve the strength and quality of sport participants’ motivation. PMID:24149690

  6. Influence of Ghrelin and Adipocytokines on Bone Mineral Density in Adolescent Female Athletes with Amenorrhea and Eumenorrheic Athletes

    PubMed Central

    Russell, Melissa; Misra, Madhusmita

    2013-01-01

    Adolescent female athletes are at increased risk for low bone mineral density (BMD) secondary to exercise-induced hypogonadism. Of particular concern is that the adolescent years are also a critical time for bone accrual, and deficits incurred during this period could lead to suboptimal peak bone mass acquisition and subsequent fracture risk in later life. Although weight bearing exercise is typically associated with an increase in BMD, amenorrheic athletes have lower BMD than eumenorrheic athletes and non-athletic controls as a consequence of low energy availability and subsequent hypogonadism. It is important to recognize that critical interactions exist between net energy availability and the hypothalamo-pituitary-gonadal (H-P-G) axis that are key to the development of a hypogonadal state when energy intake cannot keep pace with expenditure. While the link between energy availability and gonadtotropin pulsatility patterns is well established, the actual metabolic signals that link the two are less clear. Decreased energy availability in athletes is associated with decreases in fat mass, and alterations in adipokines (such as leptin and adiponectin) and fat-regulated hormones (such as ghrelin and peptide YY). These hormones impact the H-P-G axis in animal models, and it is possible that in athletes alterations in fat-related hormones signal the state of energy availability to the hypothalamus and contribute to suppression of gonadotrophin pulsatility, hypothalamic amenorrhea and consequent decreased BMD. A better understanding of pathways linking low energy availability with functional hypothalamic amenorrhea and low BMD is critical for the development of future therapeutic strategies addressing these issues in amenorrheic athletes. PMID:20956863

  7. Solar Sprint

    ERIC Educational Resources Information Center

    Tabor, Richard; Anderson, Stephen

    2007-01-01

    In the "Solar Sprint" activity, students design, test, and race a solar-powered car built with Legos. The use of ratios is incorporated to simulate the actual work of scientists and engineers. This method encourages fourth-grade students to think about multiple variables and stimulates their curiosity when an activity doesn't come out as…

  8. Influence of ghrelin and adipocytokines on bone mineral density in adolescent female athletes with amenorrhea and eumenorrheic athletes.

    PubMed

    Russell, Melissa; Misra, Madhusmita

    2010-01-01

    Adolescent female athletes are at increased risk for low bone mineral density (BMD) secondary to exercise-induced hypogonadism. Of particular concern is that the adolescent years are also a critical time for bone accrual, and deficits incurred during this period could lead to suboptimal peak bone mass acquisition and subsequent fracture risk in later life. Although weight-bearing exercise is typically associated with an increase in BMD, amenorrheic athletes have lower BMD than eumenorrheic athletes and nonathletic controls as a consequence of low energy availability and subsequent hypogonadism. It is important to recognize that critical interactions exist between net energy availability and the hypothalamo-pituitary-gonadal (H-P-G) axis that are key to the development of a hypogonadal state when energy intake cannot keep pace with expenditure. While the link between energy availability and gonadtotropin pulsatility patterns is well established, the actual metabolic signals that link the two are less clear. Decreased energy availability in athletes is associated with decreases in fat mass, and alterations in adipokines (such as leptin and adiponectin) and fat-regulated hormones (such as ghrelin and peptide YY). These hormones impact the H-P-G axis in animal models, and it is possible that in athletes alterations in fat-related hormones signal the state of energy availability to the hypothalamus and contribute to suppression of gonadotropin pulsatility, hypothalamic amenorrhea and consequent decreased BMD. A better understanding of pathways linking low energy availability with functional hypothalamic amenorrhea and low BMD is critical for the development of future therapeutic strategies addressing these issues in amenorrheic athletes. PMID:20956863

  9. Relationship Between Agility Tests and Short Sprints: Reliability and Smallest Worthwhile Difference in National Collegiate Athletic Association Division-I Football Players.

    PubMed

    Mann, J Bryan; Ivey, Pat A; Mayhew, Jerry L; Schumacher, Richard M; Brechue, William F

    2016-04-01

    The Pro-Agility test (I-Test) and 3-cone drill (3-CD) are widely used in football to assess quickness in change of direction. Likewise, the 10-yard (yd) sprint, a test of sprint acceleration, is gaining popularity for testing physical competency in football players. Despite their frequent use, little information exists on the relationship between agility and sprint tests as well the reliability and degree of change necessary to indicate meaningful improvement resulting from training. The purpose of this study was to determine the reliability and smallest worthwhile difference (SWD) of the I-Test and 3-CD and the relationship of sprint acceleration to their performance. Division-I football players (n = 64, age = 20.5 ± 1.2 years, height = 185.2 ± 6.1 cm, body mass = 107.8 ± 20.7 kg) performed duplicate trials in each test during 2 separate weeks at the conclusion of a winter conditioning period. The better time of the 2 trials for each week was used for comparison. The 10-yd sprint was timed electronically, whereas the I-Test and 3-CD were hand timed by experienced testers. Each trial was performed on an indoor synthetic turf, with players wearing multicleated turf shoes. There was no significant difference (p > 0.06) between test weeks for the I-Test (4.53 ± 0.35 vs. 4.54 ± 0.31 seconds), 3-CD (7.45 ± 0.06 vs. 7.49 ± 0.06 seconds), or 10-yd sprint (1.85 ± 0.12 vs. 1.84 ± 0.12 seconds). The intraclass correlation coefficients (ICC) for 3-CD (ICC = 0.962) and 10-yd sprint (ICC = 0.974) were slightly higher than for the I-Test (ICC = 0.914). These values lead to acceptable levels of the coefficient of variation for each test (1.2, 1.2, and 1.9%, respectively). The SWD% indicated that a meaningful improvement due to training would require players to decrease their times by 6.6% for I-Test, 3.7% for 3-CD, and 3.8% for 10-yd sprint. Performance in agility and short sprint tests are highly related and reliable in college football players, providing quantifiable

  10. Prediction of Sport Adherence Through the Influence of Autonomy-Supportive Coaching Among Spanish Adolescent Athletes

    PubMed Central

    Almagro, Bartolomé J.; Sáenz-López, Pedro; Moreno, Juan A.

    2010-01-01

    The purpose of this study was to test a motivational model of the coach-athlete relationship, based on self-determination theory and on the hierarchical model of intrinsic and extrinsic motivation. The sample comprised of 608 athletes (ages of 12-17 years) completed the following measures: interest in athlete's input, praise for autonomous behavior, perceived autonomy, intrinsic motivation, and the intention to be physically active. Structural equation modeling results demonstrated that interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Finally, intrinsic motivation predicted the intention to be physically active in the future. The results are discussed in relation to the importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Further, the results provide information related to the possible objectives of future interventions for the education of coaches, with the goal of providing them with tools and strategies to favor the development of intrinsic motivation among their athletes. In conclusion, the climate of autonomy support created by the coach can predict the autonomy perceived by the athletes which predicts the intrinsic motivation experienced by the athletes, and therefore, their adherence to athletic practice. Key points Importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Intrinsic motivation predicted the intention to be physically active in the future. PMID:24149380

  11. Prediction of sport adherence through the influence of autonomy-supportive coaching among spanish adolescent athletes.

    PubMed

    Almagro, Bartolomé J; Sáenz-López, Pedro; Moreno, Juan A

    2010-01-01

    The purpose of this study was to test a motivational model of the coach-athlete relationship, based on self-determination theory and on the hierarchical model of intrinsic and extrinsic motivation. The sample comprised of 608 athletes (ages of 12-17 years) completed the following measures: interest in athlete's input, praise for autonomous behavior, perceived autonomy, intrinsic motivation, and the intention to be physically active. Structural equation modeling results demonstrated that interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation. Finally, intrinsic motivation predicted the intention to be physically active in the future. The results are discussed in relation to the importance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes. Further, the results provide information related to the possible objectives of future interventions for the education of coaches, with the goal of providing them with tools and strategies to favor the development of intrinsic motivation among their athletes. In conclusion, the climate of autonomy support created by the coach can predict the autonomy perceived by the athletes which predicts the intrinsic motivation experienced by the athletes, and therefore, their adherence to athletic practice. Key pointsImportance of the climate of autonomy support created by the coach on intrinsic motivation and adherence to sport by adolescent athletes.Interest in athletes' input and praise for autonomous behavior predicted perceived autonomy, and perceived autonomy positively predicted intrinsic motivation.Intrinsic motivation predicted the intention to be physically active in the future. PMID:24149380

  12. Prevalence of low back pain in adolescent athletes - an epidemiological investigation.

    PubMed

    Schmidt, C P; Zwingenberger, S; Walther, A; Reuter, U; Kasten, P; Seifert, J; Günther, K-P; Stiehler, M

    2014-07-01

    Low back pain (LBP) is a common symptom in the populations of western countries, and adolescent athletes seem to be prone to LBP. The main objective of this study was to analyze the point (LBP within the last 48 h), 1-year (LBP within the last 12 months) and lifetime (LBP within the entire life) prevalence rates of LBP in adolescent athletes participating in various sports. We also assessed the characteristics of LBP and its association with potential risk factors. To this end, 272 competitive adolescent athletes involved in 31 different sports (158 males, 113 females, 15.4 ± 2.0 years, body mass index [BMI] 20.3 ± 2.4 kg/m(2)) were enrolled in a 10-month prospective clinical trial that included a questionnaire and physical examination. We found a point prevalence of 14%, a 1-year prevalence of 57%, and a lifetime prevalence of 66% for LBP. The mean age of first appearance of LBP was 13.1 ± 2.0 years. The lifetime prevalence was significantly higher in volleyball than in biathletes (74.3 vs. 45.7%, p = 0.015). Our findings confirm that LBP is a common symptom in adolescent athletes; LBP prevalence correlates with sports participation and individual competitive level. Adolescent athletes with LBP should receive a thorough diagnostic work-up and adapt training and technique correspondingly when indicated. PMID:24424960

  13. An Examination of the Dual Model of Perfectionism and Adolescent Athlete Burnout: A Short-Term Longitudinal Research

    ERIC Educational Resources Information Center

    Chen, Lung Hung; Kee, Ying Hwa; Tsai, Ying-Mei

    2009-01-01

    The dual model of perfectionism (Slade and Owens, Behav Modificat 22(3):372-390, 1998) is adopted to examine the influence of adaptive and maladaptive perfectionism on adolescent athlete burnout in Taiwan. Participants were 188 high school adolescent student-athletes (M = 16.48, SD = 0.59). They were administered the Multidimensional Inventory of…

  14. Persistent tight hamstrings following conservative treatment for apophyseal ring fracture in adolescent athletes: critical appraisal.

    PubMed

    Miyagi, Ryo; Sairyo, Koichi; Sakai, Toshinori; Tezuka, Fumitake; Kitagawa, Yasuhiro; Dezawa, Akira

    2014-01-01

    Apophyseal ring fracture is a unique disease in children and adolescents. Its clinical features include low back pain, sciatica, paravertebral muscle spasm and tenderness, restricted back motion, neurological symptoms, and tight hamstrings. For all athletes, body flexibility is one of the most important factors for better performance. Therefore, persistent tight hamstrings has a negative influence on athletic performance. In this report, we present two adolescent athletes with apophyseal ring fracture treated successfully by conservative treatment for severe low back pain (LBP) and leg pain, despite having persistent tight hamstrings for more than one year. Unlike herniated nucleus pulposus, bony fragments in the spinal canal never disappear. Although conservative treatment can alleviate LBP and leg pain, surgical removal of fragments is considered when symptoms such as tight hamstrings and restricted lumbar motion due to canal stenosis are found, particularly in athletes. PMID:25264071

  15. Relation of motivational climate and fear of failure in Taiwanese adolescent athletes.

    PubMed

    Tsai, Ying-Mei; Chen, Lung Hung

    2009-04-01

    In this study, the relationship between motivational climate and fear of failure in sport was examined. 176 adolescent athletes were recruited (M = 16.3 yr., SD = 1.3). Athletes completed the Chinese Perceived Motivational Climate in Sport Questionnaire and the Performance Failure Appraisal Inventory. Results indicated a performance climate was positively related to the fear of failure, while a mastery climate was not. PMID:19610494

  16. HIGH SCHOOL ATHLETIC PARTICIPATION AND ADOLESCENT SUICIDE: A Nationwide US Study.

    PubMed

    Sabo, Don; Miller, Kathleen E; Melnick, Merrill J; Farrell, Michael P; Barnes, Grace M

    2005-01-01

    Suicide is the third leading cause of death among US adolescents aged 15-24, with males incurring higher rates of completion than females. This study used hierarchical logistic regression analysis to test whether athletic participation was associated with lower rates of suicidal ideation and behavior among a nationally representative sample of over 16,000 US public and private high school students. Net of the effects of age, race/ethnicity, parental educational attainment, and urbanicity, high school athletic participation was significantly associated with reduced odds of considering suicide among both females and males, and reduced odds of planning a suicide attempt among females only. Though the results point to favorable health outcomes for athletes, athletic participation was also associated with higher rates of injury to male athletes who actually attempted suicide. PMID:18846245

  17. Effects of Hypohydration on Repeated 40-yd Sprint Performance.

    PubMed

    Gann, Joshua J; Green, James M; OʼNeal, Eric K; Renfroe, Lee G; Andre, Thomas L

    2016-04-01

    This study examined the effects of hypohydration on repeated 40-yd sprint performance. Anaerobically fit current and former Division II male athletes (n = 12) completed 2 bouts of 10 × 40-yd sprints followed by an agility test, dehydrated (∼3% body weight [DT]), or hydrated trial (HT). Statistical analysis of group means indicated that hypohydration had little effect on sprint times for either the first (DT= 5.38 ± 0.37; HT = 5.35 ± 0.34) or second (DT = 5.47 ± 0.39; HT = 5.42 ± 0.39) bout of 10 sprints with only sprint number 2, 5, and 6 of bout 2 reaching statistical significance. However, when individual sprint performance was considered, a greater effect was seen. In all, 83% (10 of 12) of subjects experienced a meaningful change (≥0.1 seconds) (positive or negative) in mean sprint time (DT vs. HT) for one or more bout of 10 sprints. Ratings of perceived exertion was significantly higher (∼1 unit on a 10 point scale) for DT in all sprints during bout 1 and the first 2 sprints of bout 2. These results indicate that the effect of hypohydration on repeated sprint performance varies among individuals. Some improved performance with hypohydration, while others experienced detrimental effects. Hypohydration also resulted in a particularly notable negative impact on perceptual measures of exertion even when performance was similar. PMID:26349041

  18. Physical self-concept and disturbed eating attitudes and behaviors in French athlete and non-athlete adolescent girls: direct and indirect relations.

    PubMed

    Monthuy-Blanc, Johana; Maïano, Christophe; Morin, Alexandre J S; Stephan, Yannick

    2012-06-01

    This study aims to investigate the direct and indirect associations between physical self-subdomains, physical self-worth, global self-worth, and disturbed eating attitudes and behaviors among French non-elite athlete and non-athlete adolescent girls. A sample of adolescent girls including 50 ballet dancers, 41 basketball players, and 47 non-athletes was used in this study. Data obtained from the ballet dancer and basketball player subsamples revealed significant, sample-specific as well as common, direct relations between global and physical self-perceptions and disturbed eating attitudes and behaviors, as well as significant indirect relations (via global self-worth and physical self-worth) between specific physical self-perceptions and disturbed eating attitudes and behaviors. In contrast, no association was found between global and physical self-perceptions in the sample of non-athlete adolescent girls. PMID:22622324

  19. Adolescent Educational Expectations and High School Interscholastic Athletics.

    ERIC Educational Resources Information Center

    Rehberg, Richard A.; Schafer, Walter E.

    Data from 785 male seniors from 6 urban Pennsylvania high schools are used to evaluate the relationship between post high school educational expectations and participation or non-participation in interscholastic athletic activities. A zero-order gamma of .28 indicates that educational expectations and athletic participation are positively…

  20. Development of burnout perceptions during adolescence among high-level athletes: a developmental and gendered perspective.

    PubMed

    Isoard-Gautheur, Sandrine; Guillet-Descas, Emma; Gaudreau, Patrick; Chanal, Julien

    2015-08-01

    This study examined (a) the developmental trajectories of athlete burnout perceptions, (b) the gender differences on these trajectories, and (c) the interactions in the developmental trajectories of the three burnout dimensions. A five-wave longitudinal study was conducted with 895 athletes (47.6% female; Mage = .67). Results of multilevel growth models revealed that during adolescence, "reduced sense of accomplishment" linearly decreased and was higher for girls than boys. Moreover, "emotional/physical exhaustion" increased then decreased, and seemed to have been attenuated at time points in which athletes also had higher levels of "sport devaluation." Finally, "sport devaluation" increased over time with higher increases for girls than boys. Results of our study depicted the general and the gendered shape of the trajectory of burnout perceptions during adolescence, and underlined the advantages of considering the multifaceted nature of burnout to enable a deeper examination of the within-person synergies in the development of the three dimensions. PMID:26442773

  1. Sports and Athletics: Issues for Adolescents with Chronic Illnesses and Disabilities. CYDLINE Reviews.

    ERIC Educational Resources Information Center

    Minnesota Univ., Minneapolis. National Center for Youth with Disabilities.

    This annotated bibliography focuses on issues in sports and athletics for adolescents and young adults with chronic illnesses and disabilities. The listings are drawn from the National Resource Library of the National Center for Youth with Disabilities, which includes journals, books, and non-published materials. The section on bibliographic…

  2. Isokinetic Leg Flexion and Extension Strength of Elite Adolescent Female Track and Field Athletes.

    ERIC Educational Resources Information Center

    Housh, Terry J.; And Others

    1984-01-01

    Adolescent female track-and-field athletes were measured to compare isokinetic strength of leg flexion and extension movements. Throwers, jumpers, middle-distance runners, and sprinters participated in the study. Throwers were found to be stronger in absolute strength, but there were no significant differences in relative strength. Results are…

  3. Prevalence of Achilles and patellar tendinopathy and their association to intratendinous changes in adolescent athletes.

    PubMed

    Cassel, M; Baur, H; Hirschmüller, A; Carlsohn, A; Fröhlich, K; Mayer, F

    2015-06-01

    Achilles (AT) and patellar tendons (PT) are commonly affected by tendinopathy in adult athletes but prevalence of symptoms and morphological changes in adolescents is unclear. The study aimed to determine prevalence of tendinopathy and intratendinous changes in ATs and PTs of adolescent athletes. A total of 760 adolescent athletes (13.0 ± 1.9 years; 160 ± 13 cm; 50 ± 14 kg) were examined. History, local clinical examination, and longitudinal Doppler ultrasound analysis for both ATs and PTs were performed including identification of intratendinous echoic changes and vascularization. Diagnosis of tendinopathy was complied clinically in case of positive history of tendon pain and tendon pain on palpation. Achilles tendinopathy was diagnosed in 1.8% and patellar tendinopathy in 5.8%. Vascularizations were visible in 3.0% of ATs and 11.4% of PTs, hypoechogenicities in 0.7% and 3.2% as well as hyperechogenicities in 0% and 0.3%, respectively. Vascularizations and hypoechogenicities were statistically significantly more often in males than in females (P ≤ 0.02). Subjects with patellar tendinopathy had higher prevalence of structural intratendinous changes than those without PT symptoms (P ≤ 0.001). In adolescent athletes, patellar tendinopathy is three times more frequent compared with Achilles tendinopathy. Longitudinal studies are necessary to investigate physiological or pathological origin of vascularizations and its predictive value in development of tendinopathy. PMID:25212527

  4. Racial/ethnic, gender, and BMI differences in athletic identity in children and adolescents

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this study was to examine differences in athletic self-concept, a hypothesized mediator of physical activity and sedentary behavior, by gender, racial/ethnic, and overweight status in elementary and middle school children. Children (Grades 4-5, n=936) and adolescents (Grades 7-8, n=1...

  5. Adolescent Siblings' Daily Discussions: Connections to Perceived Academic, Athletic, and Peer Competency

    ERIC Educational Resources Information Center

    Tucker, Corinna Jenkins; Winzeler, Abby

    2007-01-01

    First- and second-born adolescent siblings from 21 families completed a daily diary on each of 7 days. The frequency and content of siblings' conversations are described and the relationship between the content of siblings' discussion and their perceived academic, athletic, and peer competency is explored. Siblings most often talked about…

  6. Sex Objects, Athletes, and Sexy Athletes: How Media Representations of Women Athletes Can Impact Adolescent Girls and College Women

    ERIC Educational Resources Information Center

    Daniels, Elizabeth A.

    2009-01-01

    In contrast to the large body of research examining the negative effects of idealized media images on girls' and women's body image, little research has investigated whether media images can positively impact body concept among females. Using a between-participants experimental design, this study examined how images of performance athletes,…

  7. Toward an integrative model of doping use: an empirical study with adolescent athletes.

    PubMed

    Lazuras, Lambros; Barkoukis, Vassileios; Tsorbatzoudis, Haralambos

    2015-02-01

    The present study assessed adolescent athletes' intentions toward doping by using an integrative theoretical model. Overall, 650 adolescent athletes from team and individual sports completed an anonymous structured questionnaire including demographic information, social desirability, achievement goals, motivational regulations, sportspersonship orientations, social cognitive variables, and anticipated regret. Hierarchical regression analysis showed that the integrative model predicted 57.2% of the variance in doping intentions. Social cognitive variables and anticipated regret directly predicted doping intentions. Anticipated regret added 3% incremental variance on top of other predictors. Multiple mediation analyses showed that the effects of achievement goals on intentions were mediated by self-efficacy beliefs, whereas the effects of sportspersonship were mediated by attitudes and anticipated regret. The present study confirmed the dual structure of an integrative model of doping intentions and further highlighted the role of anticipated regret in the study of adolescent doping use. PMID:25730890

  8. Sprint performance under heat stress: A review.

    PubMed

    Girard, O; Brocherie, F; Bishop, D J

    2015-06-01

    Training and competition in major track-and-field events, and for many team or racquet sports, often require the completion of maximal sprints in hot (>30 °C) ambient conditions. Enhanced short-term (<30 s) power output or single-sprint performance, resulting from transient heat exposure (muscle temperature rise), can be attributed to improved muscle contractility. Under heat stress, elevations in skin/core temperatures are associated with increased cardiovascular and metabolic loads in addition to decreasing voluntary muscle activation; there is also compelling evidence to suggest that large performance decrements occur when repeated-sprint exercise (consisting of brief recovery periods between sprints, usually <60 s) is performed in hot compared with cool conditions. Conversely, poorer intermittent-sprint performance (recovery periods long enough to allow near complete recovery, usually 60-300 s) in hotter conditions is solely observed when exercise induces marked hyperthermia (core temperature >39 °C). Here we also discuss strategies (heat acclimatization, precooling, hydration strategies) employed by "sprint" athletes to mitigate the negative influence of higher environmental temperatures. PMID:25943658

  9. Incidence of exercise-induced asthma in adolescent athletes under different training and environmental conditions.

    PubMed

    Sidiropoulou, Maria P; Kokaridas, Dimitrios G; Giagazoglou, Paraskevi F; Karadonas, Michalis I; Fotiadou, Eleni G

    2012-06-01

    The aim of this study was to establish if there were differences in the incidence of exercise-induced bronchospasm between athletes in different sports, which take place under different environmental conditions such as open places, closed courses, and swimming pools with similar exercise intensity (football, basketball, water polo) using the free running test. The study included 90 adolescents (3 groups of 30) aged 14-18 years recruited from academies in northern Greece. All the participants were initially subjected to (a) a clinical examination and cardiorespiratory assessment by a physician and (b) free running test of a 6-minute duration and measurement with a microspirometer of the forced expiratory volume in 1 second (FEV₁). Only the participants who had measured a decrease in FEV₁ ≥ 10% were reevaluated with the microspirometer during a training session. The examination of all the participants during the free running test showed that 22 athletes, that is, 9, 8, and 5 of football, basketball, and water polo athletes, respectively, demonstrated an FEV₁ ≥ 10 drop. Reevaluation of the 22 participants during training showed that 5 out 9 (55%) football athletes, 4 out of 8 basketball athletes (50%), and none of the 5 athletes of the water polo team displayed a drop of FEV₁ ≥ 10%. Despite the absence of any significant statistical differences between the 3 groups, the analysis of variances did show a trend of a lower incidence of EIA in the water polo athletes. It was found that a football or basketball game can induce EIA in young athletes but to a lesser degree than the free running test can induce. The water polo can be a safer sport even for participants with a medical history of asthma or allergies. PMID:21912293

  10. Additional Post-Concussion Impact Exposure May Affect Recovery in Adolescent Athletes.

    PubMed

    Terwilliger, Virginia K; Pratson, Lincoln; Vaughan, Christopher G; Gioia, Gerard A

    2016-04-15

    Repeat concussion has been associated with risk for prolonged and pronounced clinical recovery in athletes. In this study of adolescent athletes, we examined whether an additional head impact within 24 h of a sports-related concussion (SRC) is associated with higher symptom burden and prolonged clinical recovery compared with a single-injury group. Forty-two student-athletes (52% male, mean age = 14.9 years) diagnosed with an SRC in a concussion clinic were selected for this study: (1) 21 athletes who sustained an additional significant head impact within 24 h of the initial injury (additional-impact group); (2) 21 single-injury athletes, age and gender matched, who sustained only one discrete concussive blow to the head (single-injury group). Groups did not differ on initial injury characteristics or pre-injury risk factors. The effect of injury status (single- vs. additional-impact) was examined on athlete- and parent-reported symptom burden (at first clinic visit) and length of recovery (LOR). Higher symptom burden was reported by the athletes and parents in the additional-impact group at the time of first visit. The additional-impact group also had a significantly longer LOR compared with the single-injury group. These findings provide preliminary, hypothesis-generating evidence for the importance of immediate removal from play following an SRC to protect athletes from re-injury, which may worsen symptoms and prolong recovery. The retrospective study design from a specialized clinical sample points to the need for future prospective studies of the relationship between single- and additional-impact injuries on symptom burden and LOR. PMID:26421452

  11. Adolescent Athletes and the Demand and Supply of Drugs to Improve Their Performance

    PubMed Central

    Laure, Patrick; Binsinger, Caroline

    2005-01-01

    The aim of this study was to gather information into the principal methods and means employed to supply adolescents with doping agents and others substances used to improve their sporting performance. We conducted a nation wide study in France among adolescent athletes, using a self-completed questionnaire. Exploitable questionnaires (n = 6402) were returned, corresponding to 48.9% for the girls and 51.1% for the boys, both aged on average from 16.1 ± 2.2 years. These adolescents practise on average 10.0 ± 5.2 hours of sport per week. 21.9% participate on a national or international competition level. Of our respondents, 4.0% (95% confidence interval: 3.5% - 4.5%) say they have been enticed into using products which are prohibited for athletes. 10.3% of the adolescents say that they have received substances to improve their performance at least once from an average of two different people. It was mostly a friend, their parents and the family doctor. On average, in 33.2% of the cases, the adolescent received the product without asking for it, and in nearly half the cases (46.6%), the adolescent paid for the product. We feel that it is necessary to better understand the ways in which this black market functions: for example; the initial sources of the products sold, the number and the ‘profiles’ of the dealers, the general organisation of the market and the sums of money involved. Key Points This study confirms the existence of a ‘black market’ for products to improve performance, which is directed at adolescent athletes engaged in high-level competitions. This market is characterized by its ease of accessibility and also the diversity of its ‘suppliers’, the two main sources being friends and parents. PMID:24453531

  12. Exercise Fatigue in Adolescents: Diagnosis of Athlete Burnout.

    ERIC Educational Resources Information Center

    Rowland, Thomas W.

    1986-01-01

    Chronic fatigue, declining performance, and mental lassitude, all symptoms of athlete burnout syndrome, require a comprehensive diagnostic approach. Many factors which can interfere with normal exercise capacity are easily treatable so a careful search is important. Three case studies are presented. (Author/MT)

  13. Contributions of athletic identity to child and adolescent physical activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Identity theorists maintain that domain-specific self-concepts help explain the differential investment of people's time and effort in various activities. This study examined the contribution of athletic identity and three key demographic variables to physical activity and sports team participation...

  14. The role and development of sprinting speed in soccer.

    PubMed

    Haugen, Thomas; Tønnessen, Espen; Hisdal, Jonny; Seiler, Stephen

    2014-05-01

    The overall objective of this review was to investigate the role and development of sprinting speed in soccer. Time-motion analyses show that short sprints occur frequently during soccer games. Straight sprinting is the most frequent action before goals, both for the scoring and assisting player. Straight-line sprinting velocity (both acceleration and maximal sprinting speed), certain agility skills, and repeated-sprint ability are shown to distinguish groups from different performance levels. Professional players have become faster over time, indicating that sprinting skills are becoming more and more important in modern soccer. In research literature, the majority of soccer-related training interventions have provided positive effects on sprinting capabilities, leading to the assumption that all kinds of training can be performed with success. However, most successful intervention studies are time consuming and challenging to incorporate into the overall soccer training program. Even though the principle of specificity is clearly present, several questions remain regarding the optimal training methods within the larger context of the team-sport setting. Considering time-efficiency effects, soccer players may benefit more by performing sprint-training regimens similar to the progression model used in strength training and by world-leading athletics practitioners, compared with the majority of guidelines that traditionally have been presented in research literature. PMID:23982902

  15. Combat sports practice favors bone mineral density among adolescent male athletes.

    PubMed

    Nasri, Raouf; Hassen Zrour, Saoussen; Rebai, Haithem; Neffeti, Fadoua; Najjar, Mohamed Fadhel; Bergaoui, Naceur; Mejdoub, Hafedh; Tabka, Zouhair

    2015-01-01

    The aim of this study was to determine the impact of combat sports practice on bone mineral density (BMD) and to analyze the relationship between bone parameters and anthropometric measurements, bone markers, and activity index (AI). In other words, to detect the most important determinant of BMD in the adolescent period among combat sports athletes. Fifty athletes engaged in combat sports, mean age 17.1±0.2 yr, were compared with 30 sedentary subjects who were matched for age, height, and pubertal stage. For all subjects, the whole-body BMD, lumbar spine BMD (L2-L4), and BMD in the pelvis, arms, and legs was measured by dual-energy X-ray absorptiometry, and anthropometric measurements were evaluated. Daily calcium intake, bone resorption, and formation markers were measured. BMD measurements were greater in the combat sports athletes than in the sedentary group (p<0.01). Weight, body mass index, and lean body mass were significantly correlated with BMD in different sites. Daily calcium consumption lower than daily calcium intake recommended in both athletes and sedentary group. AI was strongly correlated with all BMD measurements particularly with the whole body, legs, and arms. Negative correlations were observed between bone markers and BMD in different sites. The common major predictor of BMD measurements was AI (p<0.0001). AI associated to lean body mass determined whole-body BMD until 74%. AI explained both BMD in arms and L2-L4 at 25%. AI associated to height can account for 63% of the variance in BMD legs. These observations suggested that the best model predicting BMD in different sites among adolescent combat sports athletes was the AI. Children and adolescents should be encouraged to participate in combat sports to maximize their bone accrual. PMID:24176431

  16. Single-leg postural stability deficits following anterior cruciate ligament reconstruction in pediatric and adolescent athletes.

    PubMed

    Sugimoto, Dai; Howell, David R; Micheli, Lyle J; Meehan, William P

    2016-07-01

    The objective of this study was to compare the postural stability of pediatric and adolescent athletes without anterior cruciate ligament injury with those who underwent anterior cruciate reconstruction (ACLR). Postural stability ratings derived from a video-force plate system during the three stances of the modified Balance Error Scoring System were collected from pediatric and adolescent athletes who underwent ACLR (N=24; mean 1.2 years after surgery) and from uninjured controls (N=479). The postural control rating was calculated as the mean of the displacement and variance of the torso and center of pressure data, normalized on a scale from 0 to 100. A higher rating indicates greater postural stability. Participants who underwent ACLR showed lower postural stability ratings during single-leg stance compared with uninjured controls (40.0 vs. 48.7; P=0.037). ACLR is associated with deficits in postural stability. PMID:26863483

  17. The Relationship between Selected Motor Ability Determinants and Anthropometric Characteristics in Adolescent Athletes from Various Sport.

    PubMed

    Maćkala, Krzysztof; Michalski, Ryszard; Stodólka, Jacek; Rausavljević, Nikola; Čoh, Milan

    2015-07-01

    The main purpose of this study was to examine the relationship between speed, lower extremities explosive power, simple, and complex responses in adolescent athletes from various disciplines. Thirty nine athletes of 16.5 years old, N = 13 sprinters and jumpers, N = 13 soccer players, and N = 13 judokas participated in the experiment. Pearson correlations, a one-way ANOVA and an independent t-test for establishing differences between those three groups of athletes was applied. Additionally the Ward method of hierarchical cluster analysis also was applied. The strong correlation occurred between complex responses and speed; 20 m from standing and 20 m flying start (r = 0.62 and r = 0.65 respectively). In other cases, no strong association was found. The substantial differences between groups occurred in the 20 m run from flying start (t = 5.92) and standing triple jump (t = 4.16). The study indicates that adolescent athletes may need to be assessed differently to a certain extent, including sport specialization. PMID:26434022

  18. Longitudinal study of repeated sprint performance in youth soccer players of contrasting skeletal maturity status.

    PubMed

    Valente-Dos-Santos, João; Coelho-E-Silva, Manuel J; Severino, Vítor; Duarte, João; Martins, Raúl S; Figueiredo, António J; Seabra, André T; Philippaerts, Renaat M; Cumming, Sean P; Elferink-Gemser, Marije; Malina, Robert M

    2012-01-01

    The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11-13 years at baseline was assessed annually. Stature, body mass, 7x34.2-m sprint protocol (25-s active recovery), 20-m multi-stage continuous shuttle endurance run and counter-movement jump (CMJ) without the use of the arms were measured. Fat-free mass (FFM) was determined by age and gender-specific formulas. Developmental changes in total sprint time across ages were predicted using multilevel modeling. Corresponding measurements were performed on an independent cross-sectional subsample of 52 youth soccer players 11-17 years to evaluate the predictive model. CA, CA(2), maturational status (SA-CA), body size (mass and stature), FFM, aerobic endurance, lower limb explosive strength and annual volume training significantly improved the statistical fit of the RSA multilevel model. In 'late' maturing athletes, the best model for predicting change in RSA was expressed by the following equation: 86.54 - 2.87 x CA + 0.05 x CA(2) - 0.25 x FFM + 0.15 x body mass + 0.05 x stature - 0.05 x aerobic endurance - 0.09 x lower limb explosive strength - 0.01 x annual volume training. The best fitting models for players who were 'on time' and 'early' maturing were identical to the best model for late maturing players, less 0.64 seconds and 1.74 seconds, respectively. Multilevel modeling provided performance curves that permitted the prediction of individual RSA performance across adolescent years in regional level soccer players. Key pointsRepeated-sprint ability tests are a valuable sport-specific field test of sprint performance in youth soccer players. Here, the test had reasonable reliability and can be useful to trainers and coaches in the assessment of young athletes and in monitoring changes over time.The total sprint time of youth

  19. Longitudinal Study of Repeated Sprint Performance in Youth Soccer Players of Contrasting Skeletal Maturity Status

    PubMed Central

    Valente-dos-Santos, João; Coelho-e-Silva, Manuel J.; Severino, Vítor; Duarte, João; Martins, Raúl S.; Figueiredo, António J.; Seabra, André T.; Philippaerts, Renaat M.; Cumming, Sean P; Elferink-Gemser, Marije; Malina, Robert M.

    2012-01-01

    The purpose of the study was to evaluate the developmental changes in performance in a repeated-sprint ability (RSA) test in young soccer players of contrasting maturity status. A total of 83 regional level Portuguese youth soccer players, aged 11-13 years at baseline was assessed annually. Stature, body mass, 7x34.2-m sprint protocol (25-s active recovery), 20-m multi-stage continuous shuttle endurance run and counter-movement jump (CMJ) without the use of the arms were measured. Fat-free mass (FFM) was determined by age and gender-specific formulas. Developmental changes in total sprint time across ages were predicted using multilevel modeling. Corresponding measurements were performed on an independent cross-sectional subsample of 52 youth soccer players 11-17 years to evaluate the predictive model. CA, CA2, maturational status (SA-CA), body size (mass and stature), FFM, aerobic endurance, lower limb explosive strength and annual volume training significantly improved the statistical fit of the RSA multilevel model. In ‘late’ maturing athletes, the best model for predicting change in RSA was expressed by the following equation: 86.54 - 2.87 x CA + 0.05 x CA2 - 0.25 x FFM + 0.15 x body mass + 0.05 x stature - 0.05 x aerobic endurance - 0.09 x lower limb explosive strength - 0.01 x annual volume training. The best fitting models for players who were ‘on time’ and ‘early’ maturing were identical to the best model for late maturing players, less 0.64 seconds and 1.74 seconds, respectively. Multilevel modeling provided performance curves that permitted the prediction of individual RSA performance across adolescent years in regional level soccer players. Key pointsRepeated-sprint ability tests are a valuable sport-specific field test of sprint performance in youth soccer players. Here, the test had reasonable reliability and can be useful to trainers and coaches in the assessment of young athletes and in monitoring changes over time.The total sprint time

  20. Comparison of posture among adolescent male volleyball players and non-athletes

    PubMed Central

    2014-01-01

    Due to high training loads and frequently repeated unilateral exercises, several types of sports training can have an impact on the process of posture development in young athletes. The objective of the study was to assess and compare the postures of adolescent male volleyball players and their non-training peers. The study group comprised 104 volleyball players while the control group consisted of 114 non-training individuals aged 14-16 years. Body posture was assessed by the Moiré method. The volleyball players were significantly taller, and had greater body weight and fat-free mass. The analysis of posture relative to symmetry in the frontal and transverse planes did not show any significant differences between the volleyball players and non-athletes. Postural asymmetries were observed in both the volleyball players and the control participants. Lumbar lordosis was significantly less defined in the volleyball players compared to non-training individuals while no difference was observed in thoracic kyphosis. All athletes demonstrated a loss of lumbar lordosis and an increase in thoracic kyphosis. Significant differences in anteroposterior curvature of the spine between the volleyball players and the non-athletes might be associated with both training and body height. Considering the asymmetric spine overloads which frequently occur in sports training, meticulous posture assessment in young athletes seems well justified. PMID:25729154

  1. Sleep and circadian rhythms in children and adolescents: relevance for athletic performance of young people.

    PubMed

    Carskadon, Mary A

    2005-04-01

    The amount and timing of sleep play significant roles in forming a solid foundation for competitive performance in young athletes. As children mature into and through adolescence, their need for sleep does not decline substantially, although the opportunity to sleep is limited by lifestyle choices, academic and practice schedules, and compelling changes in the biological processes. The biological changes include a more "permissive" pace for the accumulation of sleep pressure across the day in older adolescents and a longer day length in the more mature. These factors all favor later bedtimes and rising times as children pass into adolescence, and a concomitant delay in the optimal timing for waking activities. Among the important threats to athletic performance are insufficient sleep during training and competition and poor appreciation for the best time of day for competitive activities. The specific consequences of these issues for individual athletes are not clear, though when considering young people as a group, support for adequate sleep is a rational intervention to maximize performance. PMID:15892926

  2. Arm-cycling sprints induce neuromuscular fatigue of the elbow flexors and alter corticospinal excitability of the biceps brachii.

    PubMed

    Pearcey, Gregory E P; Bradbury-Squires, David J; Monks, Michael; Philpott, Devin; Power, Kevin E; Button, Duane C

    2016-02-01

    We examined the effects of arm-cycling sprints on maximal voluntary elbow flexion and corticospinal excitability of the biceps brachii. Recreationally trained athletes performed ten 10-s arm-cycling sprints interspersed with 150 s of rest in 2 separate experiments. In experiment A (n = 12), maximal voluntary contraction (MVC) force of the elbow flexors was measured at pre-sprint 1, post-sprint 5, and post-sprint 10. Participants received electrical motor point stimulation during and following the elbow flexor MVCs to estimate voluntary activation (VA). In experiment B (n = 7 participants from experiment A), supraspinal and spinal excitability of the biceps brachii were measured via transcranial magnetic and transmastoid electrical stimulation that produced motor evoked potentials (MEPs) and cervicomedullary motor evoked potentials (CMEPs), respectively, during a 5% isometric MVC at pre-sprint 1, post-sprint 1, post-sprint 5, and post-sprint 10. In experiment A, mean power output, MVC force, potentiated twitch force, and VA decreased 13.1% (p < 0.001), 8.7% (p = 0.036), 27.6% (p = 0.003), and 5.6% (p = 0.037), respectively, from pre-sprint 1 to post-sprint 10. In experiment B, (i) MEPs decreased 42.1% (p = 0.002) from pre-sprint 1 to post-sprint 5 and increased 40.1% (p = 0.038) from post-sprint 5 to post-sprint 10 and (ii) CMEPs increased 28.5% (p = 0.045) from post-sprint 1 to post-sprint 10. Overall, arm-cycling sprints caused neuromuscular fatigue of the elbow flexors, which corresponded with decreased supraspinal and increased spinal excitability of the biceps brachii. The different post-sprint effects on supraspinal and spinal excitability may illustrate an inhibitory effect on supraspinal drive that reduces motor output and, therefore, decreases arm-cycling sprint performance. PMID:26799694

  3. The Influence of Significant Others on Attitudes, Subjective Norms and Intentions Regarding Dietary Supplement Use among Adolescent Athletes.

    ERIC Educational Resources Information Center

    Dunn, Michael S.; Eddy, James M.; Qi Wang, Min; Nagy, Steve; Perko, Michael A.; Bartee, R. Todd

    2001-01-01

    The purpose of this study was: (1) to determine whether attitudes are a better predictor of adolescents' intentions to use dietary supplements than are subjective norms, and (2) to assess the influence of significant others on attitudes, subjective norms, and intentions among adolescent athletes. Results indicated that attitudes were a better…

  4. Relationship between sprint ability and loaded/unloaded jump tests in elite sprinters.

    PubMed

    Loturco, Irineu; DʼAngelo, Ricardo A; Fernandes, Victor; Gil, Saulo; Kobal, Ronaldo; Cal Abad, Cesar C; Kitamura, Katia; Nakamura, Fabio Y

    2015-03-01

    The neuromechanical determinants of sprint running performance have been investigated in team sports athletes and non-elite sprinters. The aim of this study was to quantify the relationships between kinetic and performance parameters, obtained in loaded and unloaded vertical and horizontal jumps, and sprinting in elite athletes. Twenty-two sprinters performed squat jumps, countermovement jumps, horizontal jumps, and jump squats with different loads on a force platform, in addition to a 50-m sprint. Results indicated that jumping height and distance in vertical and horizontal jumps are more strongly correlated (R ≈ 0.81) to sprinting speed than the respective peak forces (R ≈ 0.36). Furthermore, the optimum load generating the maximum power in the jump squat is also highly correlated to sprint performance (R ≈ 0.72). These results reveal that vertical and horizontal jump tests may be used by coaches for assessing and monitoring qualities related to sprinting performance in elite sprinters. PMID:25162648

  5. Cold applications for recovery in adolescent athletes: a systematic review and meta analysis.

    PubMed

    Murray, Andrew; Cardinale, Marco

    2015-01-01

    Recovery and regeneration modalities have been developed empirically over the years to help and support training programmes aimed at maximizing athletic performance. Professional athletes undergo numerous training sessions, characterized by differing modalities of varying volumes and intensities, with the aim of physiological adaptation leading to improved performance. Scientific support to athletes focuses on improving the chances of a training programme producing the largest adaptive response. In competition it is mainly targeted at maximizing the chances of optimal performance and recovery when high performance levels are required repeatedly in quick succession (e.g. heats/finals). In recent years, a lot of emphasis has been put on recovery modalities. In particular, emphasis has been placed on the need to reduce the delayed onset of muscle soreness (DOMS) typically evident following training and competitive activities inducing a certain degree of muscle damage. One of the most used recovery modalities consists of cold-water immersion and/or ice/cold applications to muscles affected by DOMS. While the scientific literature has provided a rationale for such modalities to reduce pain in athletes and recreationally active adults, it is doubtful if this rationale is appropriate to aid training with adolescent athletes. In particular, since these methods have been suggested to potentially impair the muscle remodeling process leading to muscle hypertrophy. While this debate is still active in the literature, many coaches adopt such practices in youth populations, simply transferring what they see in elite sportspeople directly; without questioning the rationale, safety or effectiveness as well as the potential for such activity to reduce the adaptive potential of skeletal muscle remodeling in adolescent athletes. The aim of this review was to assess the current knowledge base on the use of ice/cold applications for recovery purposes in adolescent athletes in order to

  6. Effect of a Nutritional Intervention in Athlete's Body Composition, Eating Behaviour and Nutritional Knowledge: A Comparison between Adults and Adolescents.

    PubMed

    Nascimento, Marcus; Silva, Danielle; Ribeiro, Sandra; Nunes, Marco; Almeida, Marcos; Mendes-Netto, Raquel

    2016-01-01

    The objective of the present study is to evaluate and compare the effect of a nutritional intervention between adolescent and adult. In a before and after quasi-experimental clinical study, 32 athletes (21 adults, age range 20-32 years; 11 adolescents, age range: 12-19 years) participated in a nutritional counselling consisting of four consultations separated by an interval of 45 to 60 days. The athlete's eating behaviour, body composition and nutrition knowledge were evaluated at the beginning and at the end of the protocol. Both groups increased lean body mass and nutritional knowledge. Adolescents increased their mid-arm muscle circumference and improved meal frequency, and daily water intake. Athletes of both groups improved their ingestion of vegetables and fruits and decreased the ingestion of sweets and oils. Adolescents showed a higher prevalence of individuals that remained within or approached to the recommendations of sweets. This is the first study to evaluate and compare the effect of a nutritional intervention between adolescent and adult athletes body composition, eating behaviour and nutritional knowledge. The nutritional counselling has been effective in promoting beneficial changes on the athlete's eating behaviour, nutritional knowledge and body composition, however, some healthy changes were only experienced by adolescents, especially in the frequency of meals and the intake of sweets. PMID:27618088

  7. Ankle moment generation and maximum-effort curved sprinting performance.

    PubMed

    Luo, Geng; Stefanyshyn, Darren

    2012-11-15

    Turning at high speed along acute curves is crucial for athletic performance. One determinant of curved sprinting speed is the ground reaction force that can be created by the supporting limb; the moment generated at the ankle joint may influence such force generation. Body lean associated with curved sprints positions the ankle joints in extreme in-/eversion, and may hinder the ankle moment generation. To examine the influence of ankle moment generation on curved sprinting performance, 17 male subjects performed maximum-effort curved sprints in footwear with and without a wedge. The wedged footwear was constructed with the intention to align the ankle joints closer to their neutral frontal-plane configuration during counter-clockwise curved sprints so greater joint moments might be generated. We found, with the wedged footwear, the average eversion angle of the inside leg ankle was reduced, and the plantarflexion moment generation increased significantly. Meanwhile, the knee extension moment remained unchanged. With the wedged footwear, stance-average centripetal ground reaction force increased significantly while no difference in the vertical ground reaction force was detected. The subjects created a greater centripetal ground reaction impulse in the wedged footwear despite a shortened stance phase when compared to the control. Stance-average curved sprinting speed improved by 4.3% with the wedged footwear. The changes in ankle moment and curved sprinting speed observed in the current study supports the notion that the moment generation at the ankle joint may be a performance constraint for curved sprinting. PMID:23022207

  8. Dispositional coping, coping effectiveness, and cognitive social maturity among adolescent athletes.

    PubMed

    Nicholls, Adam R; Perry, John L; Jones, Leigh; Morley, Dave; Carson, Fraser

    2013-06-01

    It is accepted among scholars that coping changes as people mature during adolescence, but little is known about the relationship between maturity and coping. The purpose of this paper was to assess a model, which included dispositional coping, coping effectiveness, and cognitive social maturity. We predicted that cognitive social maturity would have a direct effect on coping effectiveness, and also an indirect impact via dispositional coping. Two hundred forty-five adolescent athletes completed measures of dispositional coping, coping effectiveness, and cognitive social maturity, which has three dimensions: conscientiousness, peer influence on behavior, and rule following. Using structural equation modeling, we found support for our model, suggesting that coping is related to cognitive social maturity. This information can be used to influence the content of coping interventions for adolescents of different maturational levels. PMID:23798586

  9. Analysis of Consumption of Energy Drinks by a Group of Adolescent Athletes

    PubMed Central

    Nowak, Dariusz; Jasionowski, Artur

    2016-01-01

    Background: Energy drinks (EDs) have become widely popular among young adults and, even more so, among adolescents. Increasingly, they are consumed by athletes, particularly those who have just begun their sporting career. Uncontrolled and high consumption of EDs, in addition to other sources of caffeine, may pose a threat to the health of young people. Hence, our objective was to analyze the consumption of EDs among teenagers engaged in sports, including quantity consumed, identification of factors influencing consumption, and risks associated with EDs and EDs mixed with alcohol (AmEDs). Methods: The study involved a specially designed questionnaire, which was completed by 707 students, 14.3 years of age on average, attending secondary sports schools. Results: EDs were consumed by 69% of the young athletes, 17% of whom drank EDs quite often: every day or 1–3 times a week. Most respondents felt no effects after drinking EDs, but some reported symptoms, including insomnia, anxiety, tachycardia, nervousness and irritability. The major determinant of the choice of EDs was taste (47%), followed by price (21%). One in ten respondents admitted to consumption of AmEDs. Among the consequences reported were: abdominal pains, nausea, vomiting, amnesia, headache, and hangover. Conclusions: EDs consumption among adolescent athletes was relatively high. Considering the habit of AmEDs and literature data, it is worth emphasizing that it may lead to health problems in the near future, alcohol- or drug-dependence, as well as other types of risk behaviour. PMID:27483299

  10. Sclerostin and Pref-1 have differential effects on bone mineral density and strength parameters in adolescent athletes compared with non-athletes

    PubMed Central

    Fazeli, Pouneh K.; Ackerman, Kathryn E.; Pierce, Lisa; Guereca, Gabriela; Bouxsein, Mary; Misra, Madhusmita

    2013-01-01

    Purpose Exercise activity is common in female adolescents, however, excessive exercise can have detrimental effects on bone mineral density (BMD). Mechanisms underlying this decrease in bone mass are not well understood. We investigated the effects of sclerostin, a potent inhibitor of bone formation via WNT signaling inhibition, and pre-adipocyte factor (Pref)-1, a suppressor of osteoblast differentiation, on BMD, bone turnover markers and bone strength in adolescent athletes. Methods We studied 50 adolescents between 15-21 years of age: 17 amenorrheic athletes (AA), 17 eumenorrheic athletes (EA) and 16 nonathletic controls (NA). We measured spine and hip BMD by dual energy x-ray absorptiometry and estimated failure load and stiffness at the distal radius and tibia using micro-finite element analysis. We also measured fasting sclerostin, Pref-1, N-terminal propeptide of type 1 procollagen (P1NP) and C-terminal collagen crosslinks (CTX) levels. Results Sclerostin levels were higher in AA and EA compared with NA (AA: 0.42 ± 0.15 ng/mL, EA: 0.44 ± 0.09 ng/mL, NA: 0.33 ± 0.14 ng/mL; p=0.047). In EA, sclerostin was positively associated with lumbar spine (LS) BMD and its Z-score (R=0.52, p=0.03 and R=0.55, p=0.02, respectively) whereas in NA, sclerostin was inversely associated with LS BMD (R=−0.61, p=0.01). Pref-1 levels were similar in all three groups and there were significant inverse associations between Pref-1, BMD and estimated bone strength in NA. Conclusions Sclerostin and Pref-1 may have differential effects on bone in adolescent athletes compared to non-athletes. PMID:23579340

  11. Recovery of Psychological Readiness May Differ Between Genders Following ACL Reconstruction in Adolescent Athletes

    PubMed Central

    Milewski, Matthew David; Kostyun, Regina; Iannicelli, Julie P.; Kostyun, Kyle J.; Solomito, Matthew; Nissen, Carl W.

    2016-01-01

    Objectives: Injury to the anterior cruciate ligament (ACL) is a traumatic and emotional event for adolescent athletes. Preparation to return to play (RTP) and the potential risk of re-injury are often equally as emotional as the injury, and have been identified as possible limiting factors to a successful rehabilitation and RTP. In order to create a comprehensive rehabilitation model, further understanding of psychological readiness following surgical intervention is needed. The purpose of this study was to determine if clinical outcomes of subjective knee function and psychological readiness differ between genders following ACL reconstruction surgery in adolescent athletes, and if higher knee function and physiological readiness was associated with an earlier to RTP. Methods: Athletes who underwent ACL reconstruction surgery and were successfully returned back to unrestricted sport were included in the analysis. At approximately six months post surgery, knee function was assessed using the validated International Knee Documentation Committee (IKDC) Subjective Form, and psychological readiness was assessed using the validated ACL-Return to Sport after Injury (ACL-RSI) scale. Formal clearance to resume unrestricted sport was obtained from clinic notes. A T-test was used to determine if demographics, IKDC and ACL-RSI scores between genders. A mixed effects random intercept regression model was used to determine the association of time to RTP with IKDC and ACL-RSI scores. Results: A total of 45 adolescent athletes (23 females) were included in this analysis. No significant differences were found between males and females for age (16.2±1.5 years, 16.3±2.2 years) and average time to RTP (7.3±2.0 months, 7.3±1.8 months). No significant differences in IKDC scores were found between males and females (88±10%, 87±10%). A trend was identified that males demonstrated higher ACL-RSI scores at six month post surgery than females (81±14%, 72±17%, p = 0.063). In females

  12. Repetitive Concussions in Adolescent Athletes – Translating Clinical and Experimental Research into Perspectives on Rehabilitation Strategies

    PubMed Central

    Semple, Bridgette D.; Lee, Sangmi; Sadjadi, Raha; Fritz, Nora; Carlson, Jaclyn; Griep, Carrie; Ho, Vanessa; Jang, Patrice; Lamb, Annick; Popolizio, Beth; Saini, Sonia; Bazarian, Jeffrey J.; Prins, Mayumi L.; Ferriero, Donna M.; Basso, D. Michele; Noble-Haeusslein, Linda J.

    2015-01-01

    Sports-related concussions are particularly common during adolescence, a time when even mild brain injuries may disrupt ongoing brain maturation and result in long-term complications. A recent focus on the consequences of repetitive concussions among professional athletes has prompted the development of several new experimental models in rodents, as well as the revision of guidelines for best management of sports concussions. Here, we consider the utility of rodent models to understand the functional consequences and pathobiology of concussions in the developing brain, identifying the unique behavioral and pathological signatures of concussive brain injuries. The impact of repetitive concussions on behavioral consequences and injury progression is also addressed. In particular, we focus on the epidemiological, clinical, and experimental evidence underlying current recommendations for physical and cognitive rest after concussion, and highlight key areas in which further research is needed. Lastly, we consider how best to promote recovery after injury, recognizing that optimally timed, activity-based rehabilitative strategies may hold promise for the adolescent athlete who has sustained single or repetitive concussions. The purpose of this review is to inform the clinical research community as it strives to develop and optimize evidence-based guidelines for the concussed adolescent, in terms of both acute and long-term management. PMID:25883586

  13. Consequences of single sport specialization in the pediatric and adolescent athlete.

    PubMed

    Smucny, Mia; Parikh, Shital N; Pandya, Nirav K

    2015-04-01

    Pediatric and adolescent sports participation has increased with a concomitant increase in injuries. Sports have transitioned from recreational to deliberate, structured activities wherein success is determined by achievement of 'elite' status. This has led to specialization in a single sport with intensive, repetitive activity at younger ages causing physical and emotional consequences, particularly true for the growing athlete who is particularly susceptible to injury. Clinicians caring for this population must understand the epidemiology of youth sports specialization, the unique physiology/structure of this age group, and the potential physical and emotional consequences. PMID:25771319

  14. ACTN3 Genotype, Athletic Status, and Life Course Physical Capability: Meta-Analysis of the Published Literature and Findings from Nine Studies

    PubMed Central

    Alfred, Tamuno; Ben-Shlomo, Yoav; Cooper, Rachel; Hardy, Rebecca; Cooper, Cyrus; Deary, Ian J; Gunnell, David; Harris, Sarah E; Kumari, Meena; Martin, Richard M; Moran, Colin N; Pitsiladis, Yannis P; Ring, Susan M; Sayer, Avan Aihie; Smith, George Davey; Starr, John M; Kuh, Diana; Day, Ian NM

    2011-01-01

    The ACTN3 R577X (rs1815739) genotype has been associated with athletic status and muscle phenotypes, although not consistently. Our objective was to conduct a meta-analysis of the published literature on athletic status and investigate its associations with physical capability in several new population-based studies. Relevant data were extracted from studies in the literature, comparing genotype frequencies between controls and sprint/power and endurance athletes. For life course physical capability, data were used from two studies of adolescents and seven studies in the Healthy Ageing across the Life Course (HALCyon) collaborative research program, involving individuals aged between 53 and 90+ years. We found evidence from the published literature to support the hypothesis that in Europeans the RR genotype is more common among sprint/power athletes compared with their controls. There is currently no evidence that the X allele is advantageous to endurance athleticism. We found no association between R577X and grip strength (P = 0.09, n = 7,672 in males; P = 0.90, n = 7,839 in females), standing balance, timed get up and go, or chair rises in our studies of physical capability. The ACTN3 R577X genotype is associated with sprint/power athletic status in Europeans, but does not appear to be associated with objective measures of physical capability in the general population. Hum Mutat 32:1–11, 2011. © 2011 Wiley-Liss, Inc. PMID:21542061

  15. Sex steroid and growth hormone supplementation to enhance performance in adolescent athletes.

    PubMed

    Rogol, A D

    2000-08-01

    Ergogenic aids are taken to enhance energy utilization by producing more, controlling its use, or increasing mechanical efficiency. Most athletes are looking toward enhancing performance by proper training modalities and methods; however, some look to the biochemical route for a "quick fix." Thus, the use of chemical agents is on the rise. Herein is provided information on the anabolic-androgenic agents androstenedione, dehydroepiandrosterone, and the "parent" compound, testosterone. The former two, at best, have equivocal activity, but testosterone is both anabolic and androgenic in doses that adolescents might receive. Growth hormone and insulin-like growth factor-1 are anabolic, nonandrogenic compounds with undoubted effects on the lean body mass compartment. Both are expensive, not readily available, and subject to the art of counterfeiting. Thus, very few data are available in non-growth hormone-deficient adolescents. The discussion of these agents ends with issues of fairness, ethics, and the message we attempt to project to our teenagers, whether athletes or not. PMID:10943821

  16. Coaching the Vegetarian Athlete

    ERIC Educational Resources Information Center

    Mandali, Swarna L.

    2011-01-01

    Good nutrition is important for optimal athletic performance. Adolescent athletes often depend on their coaches for nutritional information on weight management, dietary supplements, and dietary practices. Some dietary practices, such as vegetarianism, have the potential to be harmful to the adolescent athlete if not followed with careful…

  17. Sports Specialization is Associated with An Increased Risk of Developing Anterior Knee Pain in Adolescent Female Athletes

    PubMed Central

    Hall, Randon; Foss, Kim Barber; Hewett, Timothy E.; Myer, Gregory D.

    2014-01-01

    Objectives This study sought to determine if sport specialization increases the risk of anterior knee pain in adolescent female athletes. Design Retrospective cohort epidemiology study. Methods Female basketball, soccer and volleyball players (N=546) were recruited from a single county public school district in Kentucky consisting of five middle schools and four high schools. A total of 357 multi-sport, and 189 single sport (66 basketball, 57 soccer and 66 volleyball) athlete subjects were included due to their diagnosis of patellofemoral pain on physical exam. Testing consisted of completion of a standardized history and physician-administered physical examination to determine the presence of patellofemoral pain (PFP). This study compared self-reported multi-sport athletes with sport specialized athletes participating in only one sport. The sports participation data was normalized by sport season with each sport accounting for one season of exposure. Incidence rate ratios (IRR) and 95% confidence intervals (CI) were calculated and used to determine significant differences between athletes who specialized in sport in early youth and multi-sport athletes. Results Specialization in a single sport increased the relative risk of PFP incidence by 1.5 fold (95% CI 1.0 to 2.2; p=0.038) for cumulative PFP diagnoses. Specific diagnoses such as Sinding Larsen Johansson/patellar tendinopathy (95% CI 1.5 to 10.1; p=0.005) and Osgood Schlatter Disease (95% CI 1.5 to 10.1; p=0.005) demonstrated a four-fold greater relative risk in single sport compared to multiple sport athletes. Other specific PFP diagnoses such as Fat Pad, Plica, Trauma, Pes Anserine Bursitis and IT Band Tendonitis incidence were not different between single sport and multiple sport participants (p>0.05). Conclusion Early sport specialization in female adolescents is associated with increased risk of anterior knee pain disorders including PFP, Osgood Schlatter, Sinding Larsen-Johansson compared to multi

  18. Reliability of the one-repetition-maximum power clean test in adolescent athletes.

    PubMed

    Faigenbaum, Avery D; McFarland, James E; Herman, Robert E; Naclerio, Fernando; Ratamess, Nicholas A; Kang, Jie; Myer, Gregory D

    2012-02-01

    Although the power clean test is routinely used to assess strength and power performance in adult athletes, the reliability of this measure in younger populations has not been examined. Therefore, the purpose of this study was to determine the reliability of the 1-repetition maximum (1RM) power clean in adolescent athletes. Thirty-six male athletes (age 15.9 ± 1.1 years, body mass 79.1 ± 20.3 kg, height 175.1 ±7.4 cm) who had >1 year of training experience in weightlifting exercises performed a 1RM power clean on 2 nonconsecutive days in the afternoon following standardized procedures. All test procedures were supervised by a senior level weightlifting coach and consisted of a systematic progression in test load until the maximum resistance that could be lifted for 1 repetition using proper exercise technique was determined. Data were analyzed using an intraclass correlation coefficient (ICC[2,k]), Pearson correlation coefficient (r), repeated measures analysis of variance, Bland-Altman plot, and typical error analyses. Analysis of the data revealed that the test measures were highly reliable demonstrating a test-retest ICC of 0.98 (95% confidence interval = 0.96-0.99). Testing also demonstrated a strong relationship between 1RM measures in trials 1 and 2 (r = 0.98, p < 0.0001) with no significant difference in power clean performance between trials (70.6 ± 19.8 vs. 69.8 ± 19.8 kg). Bland-Altman plots confirmed no systematic shift in 1RM between trials 1 and 2. The typical error to be expected between 1RM power clean trials is 2.9 kg, and a change of at least 8.0 kg is indicated to determine a real change in lifting performance between tests in young lifters. No injuries occurred during the study period, and the testing protocol was well tolerated by all the subjects. These findings indicate that 1RM power clean testing has a high degree of reproducibility in trained male adolescent athletes when standardized testing procedures are followed and qualified

  19. Relationships between strength, sprint, and jump performance in well-trained youth soccer players.

    PubMed

    Comfort, Paul; Stewart, Al; Bloom, Laurence; Clarkson, Ben

    2014-01-01

    Research has demonstrated a clear relationship between absolute and relative strength and sprint and jump performance in adult athletes; however, this relationship in younger athletes has been less extensively studied. The aim of this study, therefore, was to determine the relationships between strength, sprint, and jump performances in well-trained youth soccer players. Thirty-four young male soccer players (17.2 ± 0.6 years; body mass, 72.62 ± 7.42 kg; height, 179.27 ± 6.58 cm) performed a predicted maximal squat test, 20-m sprints, squat jumps (SJs), and countermovement jumps (CMJs). Absolute strength showed the strongest correlations with 5-m sprint times (r = -0.596, p < 0.001, power = 0.99), SJ height (r = 0.762, p < 0.001, power = 1.00), and CMJ height (r = 0.760, p < 0.001, power = 1.00), whereas relative strength demonstrated the strongest correlation with 20-m sprint times (r = -0.672, p < 0.001, power = 0.99). The results of this study illustrate the importance of developing high levels of lower-body strength to enhance sprint and jump performance in youth soccer players, with stronger athletes demonstrating superior sprint and jump performances. PMID:23542878

  20. Acute plasma volume change with high-intensity sprint exercise.

    PubMed

    Bloomer, Richard J; Farney, Tyler M

    2013-10-01

    When exercise is of long duration or of moderate to high intensity, a decrease in plasma volume can be observed. This has been noted for both aerobic and resistance exercise, but few data are available with regard to high-intensity sprint exercise. We measured plasma volume before and after 3 different bouts of acute exercise, of varying intensity, and/or duration. On different days, men (n = 12; 21-35 years) performed aerobic cycle exercise (60 minutes at 70% heart rate reserve) and 2 different bouts of cycle sprints (five 60-second sprints at 100% maximum wattage obtained during graded exercise testing (GXT) and ten 15-second sprints at 200% maximum wattage obtained during GXT). Blood was collected before and 0, 30, and 60 minutes postexercise and analyzed for hematocrit and hemoglobin and plasma volume was calculated. Plasma volume decreased significantly for all exercise bouts (p < 0.05), with the greatest decrease noted 0 minute postexercise for both sprint bouts (∼19%) compared with aerobic exercise bouts (∼11%). By 30 minutes postexercise, plasma volume approached pre-exercise values. We conclude that acute bouts of exercise, in particular high-intensity sprint exercise, significantly decrease plasma volume during the immediate postexercise period. It is unknown what, if any negative implications these transient changes may have on exercise performance. Strength and conditioning professionals may aim to rehydrate athletes appropriately after high-intensity exercise bouts. PMID:23302756

  1. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability.

    PubMed

    Goods, Paul S R; Dawson, Brian; Landers, Grant J; Gore, Christopher J; Peeling, Peter

    2015-09-01

    To assess the impact of 'top-up' normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, 'top-up' training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this 'top-up' training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the 'top-up' training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points'Top-up' repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players.The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.'Top-up' cycling repeat-sprint training

  2. No Additional Benefit of Repeat-Sprint Training in Hypoxia than in Normoxia on Sea-Level Repeat-Sprint Ability

    PubMed Central

    Goods, Paul S.R.; Dawson, Brian; Landers, Grant J.; Gore, Christopher J.; Peeling, Peter

    2015-01-01

    To assess the impact of ‘top-up’ normoxic or hypoxic repeat-sprint training on sea-level repeat-sprint ability, thirty team sport athletes were randomly split into three groups, which were matched in running repeat-sprint ability (RSA), cycling RSA and 20 m shuttle run performance. Two groups then performed 15 maximal cycling repeat-sprint training sessions over 5 weeks, in either normoxia (NORM) or hypoxia (HYP), while a third group acted as a control (CON). In the post-training cycling RSA test, both NORM (13.6%; p = 0.0001, and 8.6%; p = 0.001) and HYP (10.3%; p = 0.007, and 4.7%; p = 0.046) significantly improved overall mean and peak power output, respectively, whereas CON did not change (1.4%; p = 0.528, and -1.1%; p = 0.571, respectively); with only NORM demonstrating a moderate effect for improved mean and peak power output compared to CON. Running RSA demonstrated no significant between group differences; however, the mean sprint times improved significantly from pre- to post-training for CON (1.1%), NORM (1.8%), and HYP (2.3%). Finally, there were no group differences in 20 m shuttle run performance. In conclusion, ‘top-up’ training improved performance in a task-specific activity (i.e. cycling); however, there was no additional benefit of conducting this ‘top-up’ training in hypoxia, since cycle RSA improved similarly in both HYP and NORM conditions. Regardless, the ‘top-up’ training had no significant impact on running RSA, therefore the use of cycle repeat-sprint training should be discouraged for team sport athletes due to limitations in specificity. Key points ‘Top-up’ repeat-sprint training performed on a cycle ergometer enhances cycle repeat-sprint ability compared to team sport training only in football players. The addition of moderate hypoxia to repeat-sprint training provides no additional performance benefits to sea-level repeat-sprint ability or endurance performance than normoxic repeat-sprint training.

  3. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating.

    PubMed

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K

    2016-03-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key pointsIn addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  4. Effects of Cycling Versus Running Training on Sprint and Endurance Capacity in Inline Speed Skating

    PubMed Central

    Stangier, Carolin; Abel, Thomas; Mierau, Julia; Hollmann, Wildor; Strüder, Heiko K.

    2016-01-01

    The purpose of this study was to compare the effects of running versus cycling training on sprint and endurance capacity in inline speed skating. Sixteen elite athletes (8 male, 8 female, 24 ± 8 yrs) were randomly assigned into 2 training groups performing either 2 session per week of treadmill running or ergometer cycling in addition to 3 skating specific sessions (technique, plyometrics, parkour) for 8 weeks. Training intensity was determined within non-specific (cycling or running) and effects on specific endurance capacity within a specific incremental exercise test. Before and after the intervention all athletes performed a specific (300m) and one non-specific (30s cycling or 200m running) all-out sprint test according to the group affiliation. To determine the accumulation of blood lactate (BLa) and glucose (BGL) 20 μl arterialized blood was drawn at rest, as well as in 1 min intervals for 10 min after the sprint test. The sport-specific peak oxygen uptake (VO2 peak) was significantly increased (+17%; p = 0.01) in both groups and highly correlated with the sprint performance (r = -0.71). BLa values decreased significantly (-18%, p = 0.02) after the specific sprint test from pre to post-testing without any group effect. However, BGL values only showed a significant decrease (-2%, p = 0.04) in the running group. The close relationship between aerobic capacity and sprint performance in inline speed skating highlights the positive effects of endurance training. Although both training programs were equally effective in improving endurance and sprint capacities, the metabolic results indicate a faster recovery after high intensity efforts for all athletes, as well as a higher reliance on the fat metabolism for athletes who trained in the running group. Key points In addition to a highly developed aerobic performance inline speed skaters also require a highly trained anaerobic capacity to be effective in the sprint sections such as the mass start, tactical attacks

  5. Effect of the coefficient of friction of a running surface on sprint time in a sled-towing exercise.

    PubMed

    Linthorne, Nicholas P; Cooper, James E

    2013-06-01

    This study investigated the effect of the coefficient of friction of a running surface on an athlete's sprint time in a sled-towing exercise. The coefficients of friction of four common sports surfaces (a synthetic athletics track, a natural grass rugby pitch, a 3G football pitch, and an artificial grass hockey pitch) were determined from the force required to tow a weighted sled across the surface. Timing gates were then used to measure the 30-m sprint time for six rugby players when towing a sled of varied weight across the surfaces. There were substantial differences between the coefficients of friction for the four surfaces (micro = 0.21-0.58), and in the sled-towing exercise the athlete's 30-m sprint time increased linearly with increasing sled weight. The hockey pitch (which had the lowest coefficient of friction) produced a substantially lower rate of increase in 30-m sprint time, but there were no significant differences between the other surfaces. The results indicate that although an athlete's sprint time in a sled-towing exercise is affected by the coefficient offriction of the surface, the relationship relationship between the athlete's rate of increase in 30-m sprint time and the coefficient of friction is more complex than expected. PMID:23898689

  6. Physics of sprinting

    NASA Astrophysics Data System (ADS)

    Alexandrov, Igor; Lucht, Philip

    1981-03-01

    Sprinting is described by a simple physical model. The model is used to predict the differences between the recorded times for races on a straight track and on a curve. It is shown that the choice of the running lane makes a non-negligible difference.

  7. Physics of Sprinting.

    ERIC Educational Resources Information Center

    Alexandrov, Igor; Lucht, Phillip

    1981-01-01

    Sprinting is described by a simple physical model. The model is used to predict the differences between the recorded times for races on a straight track and on a curve. It is shown that the choice of the running lane makes a nonnegligible difference. (Author/SK)

  8. Functional Connectivity Is Altered in Concussed Adolescent Athletes Despite Medical Clearance to Return to Play: A Preliminary Report.

    PubMed

    Newsome, Mary R; Li, Xiaoqi; Lin, Xiaodi; Wilde, Elisabeth A; Ott, Summer; Biekman, Brian; Hunter, Jill V; Dash, Pramod K; Taylor, Brian A; Levin, Harvey S

    2016-01-01

    Recovery following sports-related concussion (SRC) is slower and often more complicated in young adolescent athletes than in collegiate players. Further, the clinical decision to return to play is currently based on symptoms and cognitive performance without direct knowledge of brain function. We tested the hypothesis that brain functional connectivity (FC) would be aberrant in recently concussed, asymptomatic athletes who had been cleared to return to play. A seed-based FC analysis measured the FC of the default mode network (DMN) (seeds = anterior cingulate cortex, posterior cingulate cortex (PCC), right lateral parietal cortex, and left lateral parietal cortex) 30 days after SRC in asymptomatic high school athletes cleared to return to play (n = 13) and was compared to the FC of high school athletes with orthopedic injury (OI) (n = 13). The SRC group demonstrated greater FC than the OI group between the PCC and the ventral lateral prefrontal cortex, as well as between the right lateral parietal cortex and lateral temporal cortex (with regions both outside of and within the DMN). Additionally, the OI group demonstrated greater FC than the SRC group between right lateral parietal cortex and supramarginal gyrus. When relating the FC results to verbal memory performance approximately 1 week and 1 month after injury, significantly different between-group relations were found for the posterior cingulate and right lateral parietal cortex seeds. However, the groups did not differ in verbal memory at 1 month. We suggest that changes in FC are apparent 1-month post-SRC despite resolution of post-concussion symptoms and recovery of cognitive performance in adolescent athletes cleared to return to play. PMID:27504104

  9. Functional Connectivity Is Altered in Concussed Adolescent Athletes Despite Medical Clearance to Return to Play: A Preliminary Report

    PubMed Central

    Newsome, Mary R.; Li, Xiaoqi; Lin, Xiaodi; Wilde, Elisabeth A.; Ott, Summer; Biekman, Brian; Hunter, Jill V.; Dash, Pramod K.; Taylor, Brian A.; Levin, Harvey S.

    2016-01-01

    Recovery following sports-related concussion (SRC) is slower and often more complicated in young adolescent athletes than in collegiate players. Further, the clinical decision to return to play is currently based on symptoms and cognitive performance without direct knowledge of brain function. We tested the hypothesis that brain functional connectivity (FC) would be aberrant in recently concussed, asymptomatic athletes who had been cleared to return to play. A seed-based FC analysis measured the FC of the default mode network (DMN) (seeds = anterior cingulate cortex, posterior cingulate cortex (PCC), right lateral parietal cortex, and left lateral parietal cortex) 30 days after SRC in asymptomatic high school athletes cleared to return to play (n = 13) and was compared to the FC of high school athletes with orthopedic injury (OI) (n = 13). The SRC group demonstrated greater FC than the OI group between the PCC and the ventral lateral prefrontal cortex, as well as between the right lateral parietal cortex and lateral temporal cortex (with regions both outside of and within the DMN). Additionally, the OI group demonstrated greater FC than the SRC group between right lateral parietal cortex and supramarginal gyrus. When relating the FC results to verbal memory performance approximately 1 week and 1 month after injury, significantly different between-group relations were found for the posterior cingulate and right lateral parietal cortex seeds. However, the groups did not differ in verbal memory at 1 month. We suggest that changes in FC are apparent 1-month post-SRC despite resolution of post-concussion symptoms and recovery of cognitive performance in adolescent athletes cleared to return to play. PMID:27504104

  10. Usefulness of combined history, physical examination, electrocardiogram, and limited echocardiogram in screening adolescent athletes for risk for sudden cardiac death.

    PubMed

    Anderson, Jeffrey B; Grenier, Michelle; Edwards, Nicholas M; Madsen, Nicolas L; Czosek, Richard J; Spar, David S; Barnes, Allison; Pratt, Jesse; King, Eileen; Knilans, Timothy K

    2014-12-01

    Sudden cardiac death in the young (SCDY) is the leading cause of death in young athletes during sport. Screening young athletes for high-risk cardiac defects is controversial. The purpose of this study was to assess the utility and feasibility of a comprehensive cardiac screening protocol in an adolescent population. Adolescent athletes were recruited from local schools and/or sports teams. Each subject underwent a history and/or physical examination, an electrocardiography (ECG), and a limited echocardiography (ECHO). The primary outcome measure was identification of cardiac abnormalities associated with an elevated risk for sudden death. We secondarily identified cardiac abnormalities not typically associated with a short-term risk of sudden death. A total of 659 adolescent athletes were evaluated; 64% men. Five subjects had cardiac findings associated with an elevated risk for sudden death: prolonged QTc >500 ms (n = 2) and type I Brugada pattern (n = 1), identified with ECG; dilated cardiomyopathy (n = 1) and significant aortic root dilation; and z-score = +5.5 (n = 1). History and physical examination alone identified 76 (11.5%) subjects with any cardiac findings. ECG identified 76 (11.5%) subjects in which a follow-up ECHO or cardiology visit was recommended. Left ventricular mass was normal by ECHO in all but 1 patient with LVH on ECG. ECHO identified 34 (5.1%) subjects in whom a follow-up ECHO or cardiology visit was recommended. In conclusion, physical examination alone was ineffective in identification of subjects at elevated risk for SCDY. Screening ECHO identified patients with underlying cardiac disease not associated with immediate risk for SCDY. Cost of comprehensive cardiac screening is high. PMID:25307198

  11. Sprinting performance and resistance-based training interventions: a systematic review.

    PubMed

    Bolger, Richard; Lyons, Mark; Harrison, Andrew J; Kenny, Ian C

    2015-04-01

    The purpose of this systematic review was to search the scientific literature for original research, addressing the effects different forms of resistance-based training have on sprinting performance in competitive sprinters. Specific key words (Sprinters OR Sprint) NOT (Rugby, Soccer, Cycling, Swimming, Paralympic, and Nutrition) were used to search relevant databases through November 2013 for related literature. Original research was reviewed using the Physiotherapy Evidence Database scale. Five studies met the inclusion criteria: actively competitive adult male sprinters who participated in a resistance-based intervention (>4 weeks), with outcome measures in the form of 10- to 100-m sprint times. Exclusion criteria included acute studies (<4 weeks), nonsprinting populations, and studies with no performance outcome measures (10- to 100-m sprint times). Three of the 5 studies used both locomotor resistance and fixed plane resistance, whereas the remaining 2 studies used more fixed plane resistance, for example, squat and leg extension. Three of the studies showed a statistical improvement in sprinting performance measures, for example, a decrease in 30-m sprint time (p = 0.044), whereas 1 study showed a decrease in sprinting performance. The analysis concluded that resistance-based training has a positive effect on sprinting performance. Varied input of locomotor resistance and fixed plane resistance has resulted in similar percentage change for sprinting performance. This review adds to the body of knowledge by strongly highlighting the dearth of literature exploring the effects of resistance-based training on sprinting performance in competitive sprinters. The short duration and wide range of exercises implemented in studies to date are of concern, but coaches should not hesitate to implement well-planned resistance programs for their sprint athletes. PMID:25268287

  12. [A pilot study on adolescents of both sexes. Correlation between phenotype, athletic performances and family history to type 2 diabetes].

    PubMed

    Pomara, F; Grosso, F; Basile, D; Polizzi, V; Marcianò, C; Adamo, V; De Vita, A; Petrucci, M

    2010-10-01

    The authors have studied the influence of family history of type 2 diabetes on the physical phenotype of 47 health adolescents. In both sexes groups with positive family history (FH+) had the highest values of stature and body weight (P<0.05 for males, not significant for females), waist circumference (P<0.05 for males, not significant for females), and wrist circumference (P=0.05 for males, not significant for females). Considering athletic performance, FH+ males showed a significant higher performance in power exercises than FH- males; no significant differences were found between FH+ and FH- female groups. The study confirms that family history of type 2 diabetes can induce in both sexes precocious phenotype and athletic performances linked-related variations; larger studies are necessary to confirm these data and to verify preventive interventions promoting significant life-style changes. PMID:20940677

  13. A displaced stress fracture of the femoral neck in an adolescent female distance runner with female athlete triad: A case report.

    PubMed

    Okamoto, Shinichi; Arai, Yuji; Hara, Kunio; Tsuzihara, Takashi; Kubo, Toshikazu

    2010-01-01

    This report presents a case of a displaced stress fracture of the femoral neck in an adolescent female distance runner with amenorrhea. Both reduction and internal fixation were performed early after the injury. At 24 months postoperatively, magnetic resonance imaging and bone scintigraphy showed no positive signs of femoral head necrosis and bone union was confirmed on plain X-ray. A medical examination for the presence of the signs of the female athlete triad by checking weight, calorie intake and menstrual cycles is most important to prevent such stress fractures. Athletes as well as their coaches or parents therefore need to understand female athlete triad. PMID:20205723

  14. Comparing sports vision among three groups of soft tennis adolescent athletes: Normal vision, refractive errors with and without correction

    PubMed Central

    Chang, Shih-Tsun; Liu, Yen-Hsiu; Lee, Jiahn-Shing; See, Lai-Chu

    2015-01-01

    Background: The effect of correcting static vision on sports vision is still not clear. Aim: To examine whether sports vision (depth perception [DP], dynamic visual acuity [DVA], eye movement [EM], peripheral vision [PV], and momentary vision [MV],) were different among soft tennis adolescent athletes with normal vision (Group A), with refractive error and corrected with (Group B) and without eyeglasses (Group C). Setting and Design: A cross-section study was conducted. Soft tennis athletes aged 10–13 who played softball tennis for 2–5 years, and who were without any ocular diseases and without visual training for the past 3 months were recruited. Materials and Methods: DPs were measured in an absolute deviation (mm) between a moving rod and fixing rod (approaching at 25 mm/s, receding at 25 mm/s, approaching at 50 mm/s, receding at 50 mm/s) using electric DP tester. A smaller deviation represented better DP. DVA, EM, PV, and MV were measured on a scale from 1 (worse) to 10 (best) using ATHLEVISION software. Statistical Analysis: Chi-square test and Kruskal–Wallis test was used to compare the data among the three study groups. Results: A total of 73 athletes (37 in Group A, 8 in Group B, 28 in Group C) were enrolled in this study. All four items of DP showed significant difference among the three study groups (P = 0.0051, 0.0004, 0.0095, 0.0021). PV displayed significant difference among the three study groups (P = 0.0044). There was no significant difference in DVA, EM, and MV among the three study groups. Conclusions: Significant better DP and PV were seen among soft tennis adolescent athletes with normal vision than those with refractive error regardless whether they had eyeglasses corrected. On the other hand, DVA, EM, and MV were similar among the three study groups. PMID:26632127

  15. Relationships Between Lower-Body Muscle Structure and, Lower-Body Strength, Explosiveness and Eccentric Leg Stiffness in Adolescent Athletes

    PubMed Central

    Secomb, Josh L.; Nimphius, Sophia; Farley, Oliver R.L.; Lundgren, Lina E.; Tran, Tai T.; Sheppard, Jeremy M.

    2015-01-01

    The purpose of the present study was to determine whether any relationships were present between lower-body muscle structure and, lower-body strength, variables measured during a countermovement jump (CMJ) and squat jump (SJ), and eccentric leg stiffness, in adolescent athletes. Thirty junior male (n = 23) and female (n = 7) surfing athletes (14.8 ± 1.7 y; 1.63 ± 0.09 m; 54.8 ± 12.1 kg) undertook lower-body muscle structure assessment with ultrasonography and performed a; CMJ, SJ and an isometric mid-thigh pull (IMTP). In addition, eccentric leg stiffness was calculated from variables of the CMJ and IMTP. Moderate to very large relationships (r = 0.46-0.73) were identified between the thickness of the vastus lateralis (VL) and lateral gastrocnemius (LG) muscles, and VL pennation angle and; peak force (PF) in the CMJ, SJ and IMTP. Additionally, moderate to large relationships (r = 0.37-0.59) were found between eccentric leg stiffness and; VL and LG thickness, VL pennation angle, and LG fascicle length, with a large relationship (r = 0.59) also present with IMTP PF. These results suggest that greater thickness of the VL and LG were related to improved maximal dynamic and isometric strength, likely due to increased hypertrophy of the extensor muscles. Furthermore, this increased thickness was related to greater eccentric leg stiffness, as the associated enhanced lower-body strength likely allowed for greater neuromuscular activation, and hence less compliance, during a stretch-shortening cycle. Key points Greater thickness of the VL and LG muscles were significantly related to an enhanced ability to express higher levels of isometric and dynamic strength, and explosiveness in adolescent athletes. Isometric strength underpinned performance in the CMJ and SJ in these athletes. Greater lower-body isometric strength was significantly related to eccentric leg stiffness, which is potentially the result of greater neuromuscular activation in the muscle-tendon unit. PMID

  16. TEST‐RETEST CONSISTENCY OF A POSTURAL SWAY ASSESSMENT PROTOCOL FOR ADOLESCENT ATHLETES MEASURED WITH A FORCE PLATE

    PubMed Central

    Lee, Aaron; Hugentobler, Jason A.; Kurowski, Brad G.; Myer, Gregory D.; Riley, Michael A.

    2013-01-01

    Purpose/Background: Postural control assessments can provide a powerful means of detecting concussion‐related neurophysiological abnormalities and are considered an important part of the concussion management processes. Studies with college athletes indicate that postural sway analyzed using complexity metrics may provide a sensitive and novel way to detect post‐concussion postural control impairments. The purpose of this study was to determine if a postural sway assessment protocol (PSAP) measured using a force plate system can serve as a reliable assessment tool for adolescent athletes. Methods: The short‐term and long‐term test‐retest reliability of the PSAP was examined in a group of adolescent female athletes under eyes open and eyes closed conditions. Detrended fluctuation analysis was used to evaluate the complexity of the times series data (i.e., degree of self‐similarity across time scales). Conventional measures of standard deviation and total path length (distance traveled by the center‐of‐pressure) were also assessed. Results: The complexity and conventional measures generally demonstrated good reliability coefficients for short‐term and long‐term test‐retest reliability with both eyes open and eyes closed conditions. Intra‐class Correlation Coefficient (ICC) values ranged from .38‐.90 The highest ICC values corresponded with the short‐term reliability for the eyes open condition, while the lower ICC values corresponded with the long‐term reliability for the eyes closed condition. Conclusions: The results of this study indicate that the PSAP demonstrated good short‐term and long‐term test‐retest reliability. In addition, no evidence of learning effects was elicited through this study. Future studies should further explore the validity and feasibility of the use of this protocol for different age groups, different types of athletes, and longitudinal evaluations of post‐concussion impairments. Clinical Relevance: This

  17. Appropriate Loads for Peak-Power During Resisted Sprinting on a Non-Motorized Treadmill

    PubMed Central

    Andre, Matthew J.; Fry, Andrew C.; Lane, Michael T.

    2013-01-01

    The purpose of this study was to determine the load which allows the highest peak power for resisted sprinting on a non-motorized treadmill and to determine if other variables are related to individual differences. Thirty college students were tested for vertical jump, vertical jump peak and mean power, 10 m sprint, 20 m sprint, leg press 1 RM, leg press 1 RM relative to body weight, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM. Participants performed eight resisted sprints on a non-motorized treadmill, with increasing relative loads expressed as percent of body weight. Sprint peak power was measured for each load. Pearson correlations were used to determine if relationships between the sprint peak power load and the other variables were significant. The sprint peak power load had a mode of 35% with 73% of all participants having a relative sprint peak power load between 25–35%. Significant correlations occurred between sprint peak power load and body weight, lean body mass, vertical jump peak and mean power, leg press 1 RM, leg press 1 RM relative to lean body mass, leg press 1 RM power, and leg press power at 80% of 1 RM (r = 0.44, 0.43, 0.39, 0.37, 0.47, 0.39, 0.46, and 0.47, respectively). Larger, stronger, more powerful athletes produced peak power at a higher relative load during resisted sprinting on a non-motorized treadmill. PMID:24233103

  18. Sprint Running Performance Monitoring: Methodological and Practical Considerations.

    PubMed

    Haugen, Thomas; Buchheit, Martin

    2016-05-01

    The aim of this review is to investigate methodological concerns associated with sprint performance monitoring, more specifically the influence and magnitude of varying external conditions, technology and monitoring methodologies not directly related to human physiology. The combination of different starting procedures and triggering devices can cause up to very large time differences, which may be many times greater than performance changes caused by years of conditioning. Wind, altitude, temperature, barometric pressure and humidity can all combine to yield moderate time differences over short sprints. Sprint performance can also be affected by the athlete's clothing, principally by its weight rather than its aerodynamic properties. On level surfaces, the track compliance must change dramatically before performance changes larger than typical variation can be detected. An optimal shoe bending stiffness can enhance performance by a small margin. Fully automatic timing systems, dual-beamed photocells, laser guns and high-speed video are the most accurate tools for sprint performance monitoring. Manual timing and single-beamed photocells should be avoided over short sprint distances (10-20 m) because of large absolute errors. The validity of today's global positioning systems (GPS) technology is satisfactory for long distances (>30 m) and maximal velocity in team sports, but multiple observations are still needed as reliability is questionable. Based on different approaches used to estimate the smallest worthwhile performance change and the typical error of sprint measures, we have provided an assessment of the usefulness of speed evaluation from 5 to 40 m. Finally, we provide statistical guidelines to accurately assess changes in individual performance; i.e. considering both the smallest worthwhile change in performance and the typical error of measurement, which can be reduced while repeating the number of trials. PMID:26660758

  19. Selected Determinants of Acceleration in the 100m Sprint

    PubMed Central

    Maćkała, Krzysztof; Fostiak, Marek; Kowalski, Kacper

    2015-01-01

    The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1-repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01). PMID:25964817

  20. Selected determinants of acceleration in the 100m sprint.

    PubMed

    Maćkała, Krzysztof; Fostiak, Marek; Kowalski, Kacper

    2015-03-29

    The goal of this study was to examine the relationship between kinematics, motor abilities, anthropometric characteristics, and the initial (10 m) and secondary (30 m) acceleration phases of the 100 m sprint among athletes of different sprinting performances. Eleven competitive male sprinters (10.96 s ± 0.36 for 100 with 10.50 s fastest time) and 11 active students (12.20 s ± 0.39 for 100 m with 11.80 s fastest time) volunteered to participate in this study. Sprinting performance (10 m, 30 m, and 100 m from the block start), strength (back squat, back extension), and jumping ability (standing long jump, standing five-jumps, and standing ten-jumps) were tested. An independent t-test for establishing differences between two groups of athletes was used. The Spearman ranking correlation coefficient was computed to verify the association between variables. Additionally, the Ward method of hierarchical cluster analysis was applied. The recorded times of the 10 and 30 m indicated that the strongest correlations were found between a 1-repetition maximum back squat, a standing long jump, standing five jumps, standing ten jumps (r = 0.66, r = 0.72, r = 0.66, and r = 0.72), and speed in the 10 m sprint in competitive athletes. A strong correlation was also found between a 1-repetition maximum back squat and a standing long jump, standing five jumps, and standing ten jumps (r = 0.88, r = 0.87 and r = 0.85), but again only for sprinters. The most important factor for differences in maximum speed development during both the initial and secondary acceleration phase among the two sub-groups was the stride frequency (p<0.01). PMID:25964817

  1. Individual and relational risk factors for the development of eating disorders in adolescent aesthetic athletes and general adolescents.

    PubMed

    Francisco, Rita; Narciso, Isabel; Alarcão, Madalena

    2013-12-01

    This study compared potential risk and protective factors, levels of disordered eating (DE), and their relationship among young aesthetic athletes (elite and non-elite) and controls (N = 725; 62.5 % females; mean age = 15.3, SD = 2.1). The participants completed self-report measures (McKnight Risk Factor Survey-IV, Contour Drawing Rating Scale and Eating Disorder Examination-Questionnaire). Female elite athletes showed a greater risk of developing eating disorders than non-elite athletes and controls, with no difference between the three groups of males. Multiple group analyses revealed important differences in DE predictors. Although social pressure is the strongest DE predictor in non-elite athletes and controls, in elite athletes, the strongest DE predictor is body image dissatisfaction. Parental influences, rather than self-esteem, are predictors of DE in elite athletes, unlike the other two groups. These results show that the risk and protective factors involved in the development of DE are not universally valid. The results highlight the importance of studying specific characteristics associated with DE in aesthetic athletes. Some implications for ED risk assessment and prevention are discussed. PMID:23943379

  2. Ethnicity and spatiotemporal parameters of bilateral and unilateral transtibial amputees in a 100-m sprint.

    PubMed

    Hobara, Hiroaki; Hashizume, Satoru; Kobayashi, Yoshiyuki; Usami, Yuko; Mochimaru, Masaaki

    2016-01-01

    Similar to able-bodied sprinters, most of the medals for the 100-m sprint in past Paralympic Games and IPC Athletics World Championships were dominated by West African (WA) and Caucasian (CC) amputee sprinters, not Asian (AS) sprinters. Although these results indicate differences in sprint performance due to ethnicity, little is known about the ethnicity and spatiotemporal parameters of the 100-m sprint for amputee sprinters. The purpose of this study was to investigate the differences in the spatiotemporal parameters of WA, CC and AS sprinters with bilateral and unilateral transtibial amputations during a 100-m sprint. We analyzed 6 WA, 28 CC, and 10 AS amputee sprinters from publicly available Internet broadcasts. For each sprinter's run, the average speed, average step length, and step frequency were calculated by using the number of steps in conjunction with the official race time. No significant differences were found in the spatiotemporal parameters of the 100-m sprint for the WA and CC groups. On the other hand, the average speed of the AS group was significantly lower because of its shorter step length during the 100-m sprint. The results suggest that WA and CC sprinters would perform similarly during a 100-m sprint, but AS sprinters would not. PMID:27066362

  3. The importance of isometric maximum strength and peak rate-of-force development in sprint cycling.

    PubMed

    Stone, Michael H; Sands, William A; Carlock, Jon; Callan, Sam; Dickie, Des; Daigle, Karen; Cotton, John; Smith, Sarah L; Hartman, Michael

    2004-11-01

    This study was designed to investigate the relationship of whole-body maximum strength to variables potentially associated with track sprint-cycling success. These variables included body composition, power measures, coach's rank, and sprint-cycling times. The study was carried out in 2 parts. The first part (n = 30) served as a pilot for the second part (n = 20). Subjects for both parts ranged from international-caliber sprint cyclists to local-level cyclists. Maximum strength was measured using an isometric midthigh pull (IPF). Explosive strength was measured as the peak rate-of-force development (IPRFD) from the isometric force-time curve. Peak power was estimated from countermovement (CMJPP) and static vertical jumps (SJPP) and measured by modified Wingate tests. Athletes were ranked by the U.S. national cycling coach (part 1). Sprint times (from a standing start) were measured using timing gates placed at 25, 82.5, 165, 247.5, and 330 m of an outdoor velodrome (part 2). Maximum strength (both absolute and body-mass corrected) and explosive strength were shown to be strongly correlated with jump and Wingate power. Additionally, maximum strength was strongly correlated with both coach's rank (parts 1 and 2) and sprint cycling times (part 2). The results suggest that larger, stronger sprint cyclists have an advantage in producing power and are generally faster sprint cyclists. PMID:15574097

  4. Effects of isometric and dynamic postactivation potentiation protocols on maximal sprint performance.

    PubMed

    Lim, Julian J H; Kong, Pui W

    2013-10-01

    This study examined the effects of 3 types of postactivation potentiation (PAP) protocols (single-joint isometric, multijoint isometric, and multijoint dynamic) on subsequent 10-m, 20-m and 30-m sprint performance in 12 well-trained male track athletes (mean ± SD age = 22.4 ± 3.2 years). The subjects performed 4 protocols in a randomized order on different days as follows: control (4 minutes of passive rest), maximum voluntary isometric knee extension (3 repetitions of 3-second isometric knee extension), maximum voluntary isometric back squat (3 repetitions of 3-second isometric squat), and dynamic back squat (3 repetitions of back squats at 90% 1 repetition maximum). After each protocol, a 4-minute recovery period was incorporated before a 30-m maximal sprint assessment. Maximal sprint times at 10 m, 20 m, and 30 m were measured using timing gates to reflect sprint performance. One-way repeated measures analyses of variance revealed no differences in sprint performance among the 4 protocols at 10-m, 20-m, or 30-m intervals. There were, however, large individual variations in the response to the PAP protocols with some athletes benefiting from the PAP effect and others not. In summary, this study showed no enhancement of short-distance sprint performance after PAP protocols with a 4-minute recovery period, regardless of isometric or dynamics, single-joint or multijoint. Coaches considering the use of PAP protocols to improve sprinting performance of their athletes should exploit the effectiveness of different PAP protocols on an individual basis. PMID:23302751

  5. Asymmetry in Determinants of Running Speed During Curved Sprinting.

    PubMed

    Ishimura, Kazuhiro; Sakurai, Shinji

    2016-08-01

    This study investigates the potential asymmetries between inside and outside legs in determinants of curved running speed. To test these asymmetries, a deterministic model of curved running speed was constructed based on components of step length and frequency, including the distances and times of different step phases, takeoff speed and angle, velocities in different directions, and relative height of the runner's center of gravity. Eighteen athletes sprinted 60 m on the curved path of a 400-m track; trials were recorded using a motion-capture system. The variables were calculated following the deterministic model. The average speeds were identical between the 2 sides; however, the step length and frequency were asymmetric. In straight sprinting, there is a trade-off relationship between the step length and frequency; however, such a trade-off relationship was not observed in each step of curved sprinting in this study. Asymmetric vertical velocity at takeoff resulted in an asymmetric flight distance and time. The runners changed the running direction significantly during the outside foot stance because of the asymmetric centripetal force. Moreover, the outside leg had a larger tangential force and shorter stance time. These asymmetries between legs indicated the outside leg plays an important role in curved sprinting. PMID:27046932

  6. Total haemoglobin mass and red blood cell profile in endurance-trained and non-endurance-trained adolescent athletes.

    PubMed

    Ulrich, Gert; Bärtsch, Peter; Friedmann-Bette, Birgit

    2011-11-01

    To evaluate differences in total haemoglobin mass (tHb mass) and in red blood cell profile between elite endurance-trained (END) and non-endurance-trained (nEND) male and female adolescent athletes, tHb mass (CO rebreathing) and specific variables of red blood cell profile (haemoglobin concentration, haematocrit, erythrocyte indices) were determined in 59 elite junior athletes (29 END, 30 nEND). We hypothesized that at the age of 15-17 years, regular endurance training might induce a significant increase in tHb mass and changes in red blood cell profile. Therefore, all parameters were again determined after 6, 12 and 18 months in a subset of 27 subjects (17 END, 10 nEND). In END, tHb mass related to body weight was ~15% greater than in nEND (11.2 ± 1.6  vs. 9.7 ± 1.3 g kg(-1), P < 0.001), whereas no significant differences were observed for the red blood cell profile. In both groups, tHb mass related to body weight and the variables of red blood cell profile had not changed significantly after 6, 12 and 18 months of regular training. In conclusion, in elite junior athletes, differences in tHb mass between END and nEND were similar, however, smaller compared with previously in adult athletes reported values. At the age of 15-17 years, 18 months of regular training did not induce significant changes in tHb mass beyond alterations explained by physical growth and also variables of red blood cell profile did not change significantly. PMID:21431423

  7. Baseline strength can influence the ability of salivary free testosterone to predict squat and sprinting performance.

    PubMed

    Crewther, Blair T; Cook, Christian J; Gaviglio, Chris M; Kilduff, Liam P; Drawer, Scott

    2012-01-01

    The objective of this study was to determine if salivary free testosterone can predict an athlete's performance during back squats and sprints over time and the influence baseline strength on this relationship. Ten weight-trained male athletes were divided into 2 groups based on their 1 repetition maximum (1RM) squats, good squatters (1RM > 2.0 × body weight, n = 5) and average squatters (1RM < 1.9 × body weight, n = 5). The good squatters were stronger than the average squatters (p < 0.05). Each subject was assessed for squat 1RM and 10-m sprint times on 10 separate occasions over a 40-day period. A saliva sample was collected before testing and assayed for free testosterone and cortisol. The pooled testosterone correlations were strong and significant in the good squatters (r = 0.92 for squats, r = -0.87 for sprints, p < 0.01), but not significant for the average squatters (r = 0.35 for squats, r = -0.18 for sprints). Cortisol showed no significant correlations with 1RM squat and 10-m sprint performance, and no differences were identified between the 2 squatting groups. In summary, these results suggest that free testosterone is a strong individual predictor of squat and sprinting performance in individuals with relatively high strength levels but a poor predictor in less strong individuals. This information can assist coaches, trainers, and performance scientists working with stronger weight-trained athletes, for example, the preworkout measurement of free testosterone could indicate likely training outcomes or a readiness to train at a certain intensity level, especially if real-time measurements are made. Our results also highlight the need to separate group and individual hormonal data during the repeated testing of athletes with variable strength levels. PMID:22201698

  8. Accounting for elite indoor 200 m sprint results.

    PubMed

    Usherwood, James R; Wilson, Alan M

    2006-03-22

    Times for indoor 200 m sprint races are notably worse than those for outdoor races. In addition, there is a considerable bias against competitors drawn in inside lanes (with smaller bend radii). Centripetal acceleration requirements increase average forces during sprinting around bends. These increased forces can be modulated by changes in duty factor (the proportion of stride the limb is in contact with the ground). If duty factor is increased to keep limb forces constant, and protraction time and distance travelled during stance are unchanging, bend-running speeds are reduced. Here, we use results from the 2004 Olympics and World Indoor Championships to show quantitatively that the decreased performances in indoor competition, and the bias by lane number, are consistent with this 'constant limb force' hypothesis. Even elite athletes appear constrained by limb forces. PMID:17148323

  9. ISS Update: SPRINT Exercise Program

    NASA Video Gallery

    NASA Public Affairs Officer Amiko Kauderer interviews Lori Ploutz-Snyder, Ph.D., NASA Lead Exercise Physiology Scientist, about the SPRINT exercise program used by the crew members aboard the Inter...

  10. Heat illness. Fluid and electrolyte issues for pediatric and adolescent athletes.

    PubMed

    Squire, D L

    1990-10-01

    The primary mechanism for maintaining normal body temperature during physical exercise in the heat is the evaporation of sweat. With profuse sweating, water loss far exceeds electrolyte loss. Rigorous exercise in the heat places the athlete at risk for thermoregulatory dysfunction from dehydration. Because children are inherently less efficient thermoregulators than adults, they are at even greater risk for heat illness. The three primary syndromes of heat illness are heat cramps, heat exhaustion, and heat stroke. Treatment of heat illness is based on reduction of body temperature and rehydration. Heat stroke is a true medical emergency with a high mortality rate; immediate reduction of body temperature is critical to the survival of these patients. Prevention of heat illness is based on reducing known risk factors. Physical activity should be modified in the face of high ambient temperature and humidity. The athlete should begin exercise well hydrated; frequent consumption of cold water during exercise decreases likelihood of significant dehydration. After exercise, the athlete should continue drinking to replace fluid losses. Clothing should be lightweight; the more skin exposed, the greater the available evaporative surface. A preseason conditioning program, when combined with an 8- to 14-day period of acclimatization, further reduces the risk of heat injury. Although athletes engaged in endurance sports may benefit from drinking carbohydrate/electrolyte-containing solutions, for the majority of young athletes, cold water remains the preferred choice for fluid replacement during exercise. The relatively greater body surface area of young athletes also places them at risk for hypothermia. Special attention should be given when these athletes are competing under cold environmental conditions. PMID:2216556

  11. Hyperventilation as a strategy for improved repeated sprint performance.

    PubMed

    Sakamoto, Akihiro; Naito, Hisashi; Chow, Chin-Moi

    2014-04-01

    Repeated high-intensity sprints incur substantial anaerobic metabolic challenges and create an acidic muscle milieu that is unfavorable for subsequent performance. Hyperventilation, resulting in respiratory alkalosis, acts as a compensatory mechanism for metabolic acidosis. This study tested the hypothesis that hyperventilation performed during recovery intervals would attenuate performance decrement in repeated sprint pedaling. Thirteen male university athletes performed 10 sets of 10-second maximal pedaling on a cycle ergometer with a 60-second recovery between sets under control (spontaneous breathing) and hyperventilation conditions in a crossover counter-balanced manner. Pedaling load was set at 0.075 × body mass. Peak and mean power outputs were documented for each set to compare performance decrements for 10 sets between conditions. Hyperventilation (60 breaths per minute and end-tidal partial pressure of CO2 maintained at 20-25 mm Hg) was performed 30 seconds before each sprint set. This intervention successfully increased blood pH by 0.03-0.07 but lowered P(CO2) by 1.2-8.4 mm Hg throughout exercise (p < 0.001). The peak and mean power outputs, and blood [La] accumulation were not significantly different between the conditions. However, a significant condition × time interaction existed for peak power (p = 0.035) and mean power (p = 0.023), demonstrating an attenuation in power decrement in later sprint sets with hyperventilation. In conclusion, hyperventilation implemented during recovery intervals of repeated sprint pedaling attenuated performance decrements in later exercise bouts that was associated with substantial metabolic acidosis. The practical implication is that hyperventilation may have a strategic role for enhancing training effectiveness and may give an edge in performance outcomes. PMID:23838981

  12. Female Athlete Triad

    MedlinePlus

    ... pediatricians and adolescent medicine specialists, sports medicine doctors, nutritionists and dietitians, and mental health specialists can all ... granola bars, and fruit. Visit a dietitian or nutritionist who works with teen athletes. He or she ...

  13. High performance image processing of SPRINT

    SciTech Connect

    DeGroot, T.

    1994-11-15

    This talk will describe computed tomography (CT) reconstruction using filtered back-projection on SPRINT parallel computers. CT is a computationally intensive task, typically requiring several minutes to reconstruct a 512x512 image. SPRINT and other parallel computers can be applied to CT reconstruction to reduce computation time from minutes to seconds. SPRINT is a family of massively parallel computers developed at LLNL. SPRINT-2.5 is a 128-node multiprocessor whose performance can exceed twice that of a Cray-Y/MP. SPRINT-3 will be 10 times faster. Described will be the parallel algorithms for filtered back-projection and their execution on SPRINT parallel computers.

  14. Acute effects of a caffeine-taurine energy drink on repeated sprint performance of American college football players.

    PubMed

    Gwacham, Nnamdi; Wagner, Dale R

    2012-04-01

    Consumption of energy drinks is common among athletes; however, there is a lack of research on the efficacy of these beverages for short-duration, intense exercise. The purpose of this research was to investigate the acute effects of a low-calorie caffeine-taurine energy drink (AdvoCare Spark) on repeated sprint performance and anaerobic power in National Collegiate Athletic Association Division I football players. Twenty football players (age 19.7 ± 1.8 yr, height 184.9 ± 5.3 cm, weight 100.3 ± 21.7 kg) participated in a double-blind, randomized crossover study in which they received the energy drink or an isoenergetic, isovolumetric, non-caffeinated placebo in 2 trials separated by 7 days. The Running Based Anaerobic Sprint Test, consisting of six 35-m sprints with 10 s of rest between sprints, was used to assess anaerobic power. Sprint times were recorded with an automatic electronic timer. The beverage treatment did not significantly affect power (F = 3.84, p = .066) or sprint time (F = 3.06, p = .097). However, there was a significant interaction effect between caffeine use and the beverage for sprint times (F = 4.62, p = .045), as well as for anaerobic power (F = 5.40, p = .032), indicating a confounding effect. In conclusion, a caffeine-taurine energy drink did not improve the sprint performance or anaerobic power of college football players, but the level of caffeine use by the athletes likely influenced the effect of the drink. PMID:22349209

  15. A Commentary on Real-Time Biofeedback to Augment Neuromuscular Training for ACL Injury Prevention in Adolescent Athletes

    PubMed Central

    Kiefer, Adam W.; Kushner, Adam M.; Groene, John; Williams, Christopher; Riley, Michael A.; Myer, Gregory D.

    2015-01-01

    Anterior cruciate ligament injury and the associated long-term sequelae, such as immediate reductions in physical inactivity, increased adiposity and increased risk of osteoarthritis throughout adulthood, are a major health concern for adolescent athletes. Current interventions for injury prevention may have limited effectiveness, are susceptible to issues of compliance and have not achieved the widespread acceptance necessary to promote full adoption. Neuromuscular training (NMT) is a well-established training intervention introduced to affect change in modifiable biomechanical risk factors to reduce the risk of injury in these athletes. Despite moderate success, neuromuscular training is still limited by its reliance on subjective feedback and after the fact (i.e., offline) objective feedback techniques. The purpose of this commentary is to discuss technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement NMT. Electromyography, force plates, motion sensors, and camera-based motion capture systems are innovative tools that may have realistic feasibility for integration as biofeedback into NMT programs to improve training outcomes. Improved functional deficit identification and corrective analysis may further improve and optimize athletic performance, and decrease the risk of sports-related injury during sport performance. Key points Specific, targeted interventions that isolate injury risk factors and can help correct modifiable neuromuscular deficits are essential. Current training interventions for anterior cruciate ligament (ACL) injury prevention have only demonstrated limited effectiveness and have not achieved the widespread acceptance necessary to promote full adoption to reduce ACL injury rates. The paper provides an overview of innovative strategies and technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement neuromuscular training (NMT

  16. Athlete's Foot

    MedlinePlus

    ... Homework? Here's Help White House Lunch Recipes Athlete's Foot KidsHealth > For Kids > Athlete's Foot Print A A ... a public shower. Why Is It Called Athlete's Foot? Athlete's foot gets its name because athletes often ...

  17. Alterations in resting-state brain networks in concussed adolescent athletes.

    PubMed

    Borich, Michael; Babul, Aliya-Nur; Yuan, Po Hsiang; Boyd, Lara; Virji-Babul, Naznin

    2015-02-15

    Sports-related concussion in adolescents is a major public health issue; however, little is known about the underlying changes in functional brain connectivity. We evaluated connectivity of resting-state brain networks to determine whether alterations in specific networks distinguish adolescents with sports-related concussion from a group of healthy, active control adolescents. Twelve adolescents with a clinical diagnosis of subacute concussion and ten healthy adolescents matched for age, gender, and physical activity completed functional magnetic resonance imaging (fMRI) scanning. Functional connectivity of resting-state brain networks was evaluated in both groups using probabilistic independent component analysis (ICA). Altered functional connectivity was found within three resting-state networks in adolescents with concussion. Specifically, we noted: a) alterations within the default mode network; b) increased connectivity in the right frontal pole in the executive function network; and c) increased connectivity in the left frontal operculum cortex associated with the ventral attention network. This preliminary report shows that whole-brain functional connectivity is altered in networks related to cognition and attention in adolescents in the subacute phase following sports-related concussion. This first report in adolescents should be used to inform future studies in larger cohorts of adolescents with sports-related concussion. Increased knowledge of these changes may lead to improvements in clinical management and help to develop rehabilitation programs. PMID:25010041

  18. A Qualitative Exploration of Adolescents' Commitment to Athletics and the Arts.

    ERIC Educational Resources Information Center

    Fredricks, Jennifer A.; Alfred-Liro, Corinne J.; Hruda, Ludmila Z.; Eccles, Jacquelynne S.; Patrick, Helen; Ruan, Allison M.

    2002-01-01

    Examined factors that influence adolescents' commitments to extracurricular activities over time. Found that psychological factors of perceived competence and peer relationships, as well as contextual factors of perceived challenge, cost, benefits, and emerging identity, were decisive in adolescents' choice to remain involved in activities or…

  19. Disordered Eating and Weight Control among Adolescent Female Athletes and Performance Squad Members.

    ERIC Educational Resources Information Center

    Taub, Diane E.; Blinde, Elaine M.

    1994-01-01

    Adolescents and individuals participating in activities that emphasize body shape and control have been identified as risk groups for eating disorders. A study sought to determine whether certain groups of adolescent females are more vulnerable to disordered eating patterns or usage of pathogenic weight control techniques. Involvement in organized…

  20. The approach to elbow pain in the pediatric and adolescent throwing athlete.

    PubMed

    Hammoud, Sommer; Sgromolo, Nicole; Atanda, Alfred

    2014-02-01

    Elbow pain in pediatric throwing athletes can be very concerning and challenging to diagnose. Diagnosis involves determining whether the injury is chronic or acute in nature and the anatomical location of the pain. Physicians should be aware of the sport-specific forces that predispose athletes with immature skeletons to injury and should be familiar with the common presentations of these injuries. In order to narrow the diagnosis, physicians should gather a detailed history of how and when the pain occurred in addition to performing a thorough physical exam that includes tests, such as the modified milking maneuver and the moving valgus stress test. Appropriate imaging helps physicians to confirm the diagnosis and elucidates any associated pathology in patients. In most cases, the treatment given to patients is conservative and involves rest, ice, non-steroidal anti-inflammatory drugs for pain, and an appropriate physical therapy regimen with a progressive return to play when symptoms have resolved. When patients fail to respond to conservative treatment, surgical intervention may be needed. Knowing when to refer patients for orthopedic evaluation helps athletes return to play quickly and safely. PMID:24565822

  1. The impact of the achievement motive on athletic performance in adolescent football players.

    PubMed

    Zuber, Claudia; Conzelmann, Achim

    2014-01-01

    Researchers largely agree that there is a positive relationship between achievement motivation and athletic performance, which is why the achievement motive is viewed as a potential criterion for talent. However, the underlying mechanism behind this relationship remains unclear. In talent and performance models, main effect, mediator and moderator models have been suggested. A longitudinal study was carried out among 140 13-year-old football talents, using structural equation modelling to determine which model best explains how hope for success (HS) and fear of failure (FF), which are the aspects of the achievement motive, motor skills and abilities that affect performance. Over a period of half a year, HS can to some extent explain athletic performance, but this relationship is not mediated by the volume of training, sport-specific skills or abilities, nor is the achievement motive a moderating variable. Contrary to expectations, FF does not explain any part of performance. Aside from HS, however, motor abilities and in particular skills also predict a significant part of performance. The study confirms the widespread assumption that the development of athletic performance in football depends on multiple factors, and in particular that HS is worth watching in the medium term as a predictor of talent. PMID:24041313

  2. CNTFR Genotype and Sprint/power Performance: Case-control Association and Functional Studies.

    PubMed

    Miyamoto-Mikami, E; Fujita, Y; Murakami, H; Ito, M; Miyachi, M; Kawahara, T; Fuku, N

    2016-05-01

    The aim of this study was to investigate whether rs41274853 in the 3'-untranslated region of the ciliary neurotrophic factor receptor gene (CNTFR) is associated with elite sprint/power athletic status and assess its functional significance. A total of 211 Japanese sprint/power track and field athletes (62 international, 72 national, and 77 regional athletes) and 814 Japanese controls were genotyped at rs41274853. Luciferase reporter assay was conducted to investigate whether this C-to-T polymorphism affects binding of microRNA miR-675-5p to this region. The TT genotype was significantly more frequent among international sprint/power athletes (19.4%) than in the controls after Bonferroni correction (7.9%, P=0.036, OR=2.81 [95% CI: 1.43-5.55]). Furthermore, in non-athletic young/middle-aged men (n=132), TT genotype carriers exhibited significantly greater leg extension power (26.6±5.4 vs. 24.0±5.4 W/kg BW, P=0.019) and vertical jump performance (50.1±6.9 vs. 47.9±7.5 cm, P=0.047) than the CC+CT genotype carriers. Reporter assays revealed that the miR-675-5p binds to this polymorphic region within the CNTFR mRNA, irrespective of the rs41274853 allele present. Although the functional significance of the rs41274853 polymorphism remains unclear, the CNTFR is one of the candidate genes contributing to sprint/power performance. PMID:26837930

  3. Interaction Between Leg Muscle Performance and Sprint Acceleration Kinematics

    PubMed Central

    Lockie, Robert G.; Jalilvand, Farzad; Callaghan, Samuel J.; Jeffriess, Matthew D.; Murphy, Aron J.

    2015-01-01

    This study investigated relationships between 10 m sprint acceleration, step kinematics (step length and frequency, contact and flight time), and leg muscle performance (power, stiffness, strength). Twenty-eight field sport athletes completed 10 m sprints that were timed and filmed. Velocity and step kinematics were measured for the 0–5, 5–10, and 0–10 m intervals to assess acceleration. Leg power was measured via countermovement jumps (CMJ), a five-bound test (5BT), and the reactive strength index (RSI) defined by 40 cm drop jumps. Leg stiffness was measured by bilateral and unilateral hopping. A three-repetition maximum squat determined strength. Pearson’s correlations and stepwise regression (p ≤ 0.05) determined velocity, step kinematics, and leg muscle performance relationships. CMJ height correlated with and predicted velocity in all intervals (r = 0.40–0.54). The 5BT (5–10 and 0–10 m intervals) and RSI (5–10 m interval) also related to velocity (r = 0.37–0.47). Leg stiffness did not correlate with acceleration kinematics. Greater leg strength related to and predicted lower 0–5 m flight times (r = −0.46 to −0.51), and a longer 0–10 m step length (r = 0.38). Although results supported research emphasizing the value of leg power and strength for acceleration, the correlations and predictive relationships (r2 = 0.14–0.29) tended to be low, which highlights the complex interaction between sprint technique and leg muscle performance. Nonetheless, given the established relationships between speed, leg power and strength, strength and conditioning coaches should ensure these qualities are expressed during acceleration in field sport athletes. PMID:26839607

  4. A Commentary on Real-Time Biofeedback to Augment Neuromuscular Training for ACL Injury Prevention in Adolescent Athletes.

    PubMed

    Kiefer, Adam W; Kushner, Adam M; Groene, John; Williams, Christopher; Riley, Michael A; Myer, Gregory D

    2015-03-01

    Anterior cruciate ligament injury and the associated long-term sequelae, such as immediate reductions in physical inactivity, increased adiposity and increased risk of osteoarthritis throughout adulthood, are a major health concern for adolescent athletes. Current interventions for injury prevention may have limited effectiveness, are susceptible to issues of compliance and have not achieved the widespread acceptance necessary to promote full adoption. Neuromuscular training (NMT) is a well-established training intervention introduced to affect change in modifiable biomechanical risk factors to reduce the risk of injury in these athletes. Despite moderate success, neuromuscular training is still limited by its reliance on subjective feedback and after the fact (i.e., offline) objective feedback techniques. The purpose of this commentary is to discuss technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement NMT. Electromyography, force plates, motion sensors, and camera-based motion capture systems are innovative tools that may have realistic feasibility for integration as biofeedback into NMT programs to improve training outcomes. Improved functional deficit identification and corrective analysis may further improve and optimize athletic performance, and decrease the risk of sports-related injury during sport performance. Key pointsSpecific, targeted interventions that isolate injury risk factors and can help correct modifiable neuromuscular deficits are essential.Current training interventions for anterior cruciate ligament (ACL) injury prevention have only demonstrated limited effectiveness and have not achieved the widespread acceptance necessary to promote full adoption to reduce ACL injury rates.The paper provides an overview of innovative strategies and technological tools that could be used to enhance and objectify targeted biofeedback interventions to complement neuromuscular training (NMT) including

  5. Supplement use by Young Athletes

    PubMed Central

    McDowall, Jill Anne

    2007-01-01

    This paper reviews studies of supplement use among child and adolescent athletes, focusing on prevalence and type of supplement use, as well as gender comparisons. Supplement use among adult athletes has been well documented however there are a limited number of studies investigating supplement use by child and adolescent athletes. A trend in the current literature revealed that the most frequently used supplements are in the form of vitamin and minerals. While health and illness prevention are the main reasons for taking supplements, enhanced athletic performance was also reported as a strong motivating factor. Generally, females are found to use supplements more frequently and are associated with reasons of health, recovery, and replacing an inadequate diet. Males are more likely to report taking supplements for enhanced performance. Both genders equally rated increased energy as another reason for engaging in supplement use. Many dietary supplements are highly accessible to young athletes and they are particularly vulnerable to pressures from the media and the prospect of playing sport at increasingly elite levels. Future research should provide more direct evidence regarding any physiological side effects of taking supplements, as well as the exact vitamin and mineral requirements for child and adolescent athletes. Increased education for young athletes regarding supplement use, parents and coaches should to be targeted to help the athletes make the appropriate choices. Key pointsSupplement use among the child and adolescent athlete population is widespread with the most frequently used supplement being a form of vitamin/mineral supplement.The effects of supplement use on the growth and development of children and adolescents remain unclear and thus use of supplements by this population should be discouraged.It is likely that there is a misunderstanding as to the role of vitamins and minerals in the diet, their function in maintaining overall health, their role

  6. Basal Metabolic Rate of Adolescent Modern Pentathlon Athletes: Agreement between Indirect Calorimetry and Predictive Equations and the Correlation with Body Parameters

    PubMed Central

    Loureiro, Luiz Lannes; Fonseca, Sidnei; Castro, Natalia Gomes Casanova de Oliveira e; dos Passos, Renata Baratta; Porto, Cristiana Pedrosa Melo; Pierucci, Anna Paola Trindade Rocha

    2015-01-01

    Purpose The accurate estimative of energy needs is crucial for an optimal physical performance among athletes and the basal metabolic rate (BMR) equations often are not well adjusted for adolescent athletes requiring the use of specific methods, such as the golden standard indirect calorimetry (IC). Therefore, we had the aim to analyse the agreement between the BMR of adolescents pentathletes measured by IC and estimated by commonly used predictive equations. Methods Twenty-eight athletes (17 males and 11 females) were evaluated for BMR, using IC and the predictive equations Harris and Benedict (HB), Cunningham (CUN), Henry and Rees (HR) and FAO/WHO/UNU (FAO). Body composition was obtained using DXA and sexual maturity data were retrieved through validated questionnaires. The correlations among anthropometric variables an IC were analysed by T-student test and ICC, while the agreement between IC and the predictive equations was analysed according to Bland and Altman and by survival-agreement plotting. Results The whole sample average BMR measured by IC was significantly different from the estimated by FAO (p<0.05). Adjusting data by gender FAO and HR equations were statistically different from IC (p <0.05) among males, while female differed only for the HR equation (p <0.05). Conclusion The FAO equation underestimated athletes’ BMR when compared with IC (T Test). When compared to the golden standard IC, using Bland and Altman, ICC and Survival-Agreement, the equations underestimated the energy needs of adolescent pentathlon athletes up to 300kcal/day. Therefore, they should be used with caution when estimating individual energy requirements in such populations. PMID:26569101

  7. Influence of cerebral and muscle oxygenation on repeated-sprint ability.

    PubMed

    Smith, Kurt J; Billaut, François

    2010-07-01

    The study examined the influence of cerebral (prefrontal cortex) and muscle (vastus lateralis) oxygenation on the ability to perform repeated, cycling sprints. Thirteen team-sport athletes performed ten, 10-s sprints (with 30 s of rest) under normoxic (F(I)O(2) 0.21) and acute hypoxic (F(I)O(2) 0.13) conditions in a randomised, single-blind fashion and crossover design. Mechanical work was calculated and arterial O(2) saturation (S(p)O(2)) was estimated via pulse oximetry for every sprint. Cerebral and muscle oxy-(O(2)Hb), deoxy-(HHb), and total haemoglobin (THb) were monitored continuously by near-infrared spectroscopy. Compared with normoxia, hypoxia induced larger decrements in S(p)O(2) and work (11.6 and 7.6%, respectively; P < 0.05). In the muscle, we observed a fairly constant level of deoxygenation across sprints, with no effect of the condition. In normoxia, regional cerebral oxygenation increased during the first two sprints and slightly fluctuated thereafter. In contrast, this initial cerebral hyper-oxygenation was attenuated in hypoxia. Changes in [O(2)Hb] and [HHb] occurred earlier and were larger in hypoxia compared with normoxia (P < 0.05), while regional blood volume (Delta[THb]) remained unaffected by the condition. Changes in cerebral [HHb] and mechanical work were strongly correlated in normoxia and hypoxia (R(2) = 0.81 and R(2) = 0.85, respectively; P < 0.05), although the slope of this relationship differed (normoxia, -351.3 +/- 183.3 vs. hypoxia, -442.4 +/- 227.2; P < 0.05). The results of this NIRS study show that O(2) availability influences prefrontal cortex, but not muscle, oxygenation during repeated, short sprints. By using a hypoxia paradigm, the study suggests that cerebral oxygenation contributes to the impairment of repeated-sprint ability. PMID:20354718

  8. Passive Recovery Promotes Superior Performance and Reduced Physiological Stress Across Different Phases of Short-Distance Repeated Sprints.

    PubMed

    Scanlan, Aaron T; Madueno, Maria C

    2016-09-01

    Scanlan, AT and Madueno, MC. Passive recovery promotes superior performance and reduced physiological stress across different phases of short-distance repeated sprints. J Strength Cond Res 30(9): 2540-2549, 2016-Limited research has examined the influence of recovery modalities on run-based repeated-sprint (RS) performance with no data available relative to the sprint phase. This study compared run-based RS performance across various sprint phases and underlying physiological responses between active and passive recoveries. Nine students (21.8 ± 3.6 years; 171.3 ± 6.4 cm; 72.8 ± 12.2 kg) completed 2 bouts (active and passive recoveries) of 10 × 20 m sprints interspersed with 30 s recoveries in a randomized crossover fashion. Sprint times and decrements were calculated for each split (0-5, 5-15, 15-20, and 0-20 m) across each sprint. Blood lactate concentration ([BLa]), heart rate (HR), and rating of perceived exertion (RPE) were measured at various time-points. Passive recovery promoted improved performance times (p ≤ 0.005) and decrements (p ≤ 0.045) across all splits, and lower post-test [BLa] (p ≤ 0.005), HR (bout 3 onwards) (p ≤ 0.014), and RPE (bout 4 onwards) when compared with active recovery. Performance differences between recoveries were less pronounced across the 0-5 m split. Temporal analyses showed significant (p ≤ 0.05) increases in sprint times and decrements primarily with active recovery. The present data indicate that passive recovery promoted superior performance across run-based RS, with earlier performance deterioration and greater physiological load evident during active recovery. These findings can aid the manipulation of interbout activity across RS drills to promote physiological overload and adaptation during training. Further, coaches may develop tactical strategies to overcome the detrimental effects of active recovery and optimize sprint performance in athletes during game-play. PMID:26808862

  9. Effects of a Body-Weight Supporting Kite on Sprint Running Kinematics in Well-Trained Sprinters.

    PubMed

    Kratky, Sascha; Buchecker, Michael; Pfusterschmied, Jürgen; Szekely, Csaba; Müller, Erich

    2016-01-01

    Data of elite sprinters indicate that faster athletes realize shorter ground contact times compared with slower individuals. Furthermore, the importance of the so-called "front side mechanics" for elite sprint performance is frequently emphasized by researchers and coaches. Recently, it was demonstrated that using a body-weight supporting kite during full-effort sprints in highly trained sprinters leads to a reduction in ground contact time. The aim of this study was to investigate possible negative effects of this body-weight supporting device on sprint running kinematics, which was not clarified in previous studies. Eleven well-trained Austrian sprinters performed flying 20-m sprints under 2 conditions: (a) free sprint (FS); and (b) body-weight supported sprint (BWS). Sprint cycle characteristics were recorded during the high-speed phase by a 16 camera 3D-system (Vicon), an optical acquisition system (Optojump-next), and a high-speed camera. Paired sample t-tests and Cohen's d effect size were used to determine differences between sprinting conditions. Compared with FS, BWS caused a decrease in ground contact time by 5.6% and an increase in air time by 5.5% (both p < 0.001), whereas stride length and rate remained unchanged. Furthermore, a reduced hip joint extension at and after take-off, an increased maximal hip joint flexion (i.e., high knee position), and a smaller horizontal distance of the touchdown to the center of gravity could be observed (all p < 0.01). These results indicate no negative effects on front side mechanics during BWS and that sprinting with a body-weight supporting kite seems to be a highly specific method to reduce ground contact time in well-trained sprinters. PMID:26270692

  10. Faster Futsal Players Perceive Higher Training Loads and Present Greater Decreases in Sprinting Speed During the Preseason.

    PubMed

    Nakamura, Fábio Y; Pereira, Lucas A; Rabelo, Felipe N; Ramirez-Campillo, Rodrigo; Loturco, Irineu

    2016-06-01

    Nakamura, FY, Pereira, LA, Rabelo, FN, Ramirez-Campillo, R, and Loturco, I. Faster futsal players perceive higher training loads and present greater decreases in sprinting speed during the preseason. J Strength Cond Res 30(6): 1553-1562, 2016-The aims of this study were to assess the speed-power characteristics of professional futsal players before and after a 9-week preseason and to explore possible relationships with internal training loads. Ten under-20 professional Brazilian futsal players performed unloaded (squat jump [SJ] and countermovement jump [CMJ]) and loaded (jump squat [JS]) jumps and a 20-m sprint test before and after the preseason. Weekly training loads as measured by session rating of perceived exertion (s-RPE) varied between 2,179 and 5,519 a.u. The magnitude-based inference statistics revealed that performance in the SJ, CMJ, and 20-m sprint very likely decreased (effect size [ES] = -0.64, -0.49, and -0.92, respectively), whereas mean propulsive power in the JS likely increased (ES = 0.42) in response to the preseason. The Pearson coefficient of correlation between velocity in the 20 m sprint test and s-RPE during the first 2 weeks of training was 0.66 (p ≤ 0.05) while no significant correlation was detected between total s-RPE (i.e., 9 weeks) and changes in the power-speed tests. The baseline 20-m sprint velocity was very largely and inversely (r = -0.90) correlated with the change in the 20-m sprint performance. In conclusion, futsal preseason training leads to impaired unloaded vertical jump and sprint test performance, with speed decreasing more in faster than slower players. In addition, because of the large correlation between baseline sprint ability and s-RPE, coaches are advised to assess sprinting performance at the beginning of the preseason to finely adjust the training stimuli to each athlete. PMID:26562717

  11. The Influence of Serial Carbohydrate Mouth Rinsing on Power Output during a Cycle Sprint

    PubMed Central

    Phillips, Shaun M.; Findlay, Scott; Kavaliauskas, Mykolas; Grant, Marie Clare

    2014-01-01

    output with the carbohydrate mouth rinse may come at a relative cost for the remainder of the sprint, evidenced by non-significantly lower mean power output and a greater fatigue index in the carbohydrate vs. placebo trial. Serial administration of a carbohydrate mouth rinse may be beneficial for sprint athletes as a method of performance enhancement that minimizes the risk of performance decrement through body mass increase and gastrointestinal disturbances associated with ingesting carbohydrate solutions. PMID:24790476

  12. Extracurricular Activities, Athletic Participation, and Adolescent Alcohol Use: Gender-Differentiated and School-Contextual Effects

    ERIC Educational Resources Information Center

    Hoffmann, John P.

    2006-01-01

    This research investigates the effects of extracurricular activities on alcohol use among male (n = 4,495) and female (n = 5,398) adolescents who participated in the 1990-92 National Education Longitudinal Study. Previous studies have assessed the association between extracurricular activities and alcohol use, but none have explored whether the…

  13. Evaluation and Management of Patellar Instability in Pediatric and Adolescent Athletes

    PubMed Central

    Khormaee, Sariah; Kramer, Dennis E.; Yen, Yi-Meng; Heyworth, Benton E.

    2015-01-01

    Context: The rising popularity and intensity of youth sports has increased the incidence of patellar dislocation. These sports-related injuries may be associated with significant morbidity in the pediatric population. Treatment requires understanding and attention to the unique challenges in the skeletally immature patient. Evidence Acquisition: PubMed searches spanning 1970-2013. Study Design: Clinical review. Level of Evidence: Level 5. Results: Although nonoperative approaches are most often suitable for first-time patellar dislocations, surgical treatment is recommended for acute fixation of displaced osteochondral fractures sustained during primary instability and for patellar realignment in the setting of recurrent instability. While a variety of procedures can prevent recurrence, the risk of complications is not minimal. Conclusion: Patellar stabilization and realignment procedures in skeletally immature patients with recurrent patellar dislocation can effectively treat patellar instability without untoward effects on growth if careful surgical planning incorporates protection of growth parameters in the skeletally immature athlete. PMID:25984256

  14. Repeated Sprints: An Independent Not Dependent Variable.

    PubMed

    Taylor, Jonathan M; Macpherson, Tom W; Spears, Iain R; Weston, Matthew

    2016-07-01

    The ability to repeatedly perform sprints has traditionally been viewed as a key performance measure in team sports, and the relationship between repeated-sprint ability (RSA) and performance has been explored extensively. However, when reviewing the repeated-sprint profile of team-sports match play it appears that the occurrence of repeated-sprint bouts is sparse, indicating that RSA is not as important to performance as commonly believed. Repeated sprints are, however, a potent and time-efficient training strategy, effective in developing acceleration, speed, explosive leg power, aerobic power, and high-intensity-running performance--all of which are crucial to team-sport performance. As such, we propose that repeated-sprint exercise in team sports should be viewed as an independent variable (eg, a means of developing fitness) as opposed to a dependent variable (eg, a means of assessing fitness/performance). PMID:27197118

  15. Injuries to the Young Athlete.

    ERIC Educational Resources Information Center

    Sandusky, Jane C.

    A review of literature on the incidence and nature of injuries to young athletes is presented on the topics of: (1) physiological characteristics of preadolescents, adolescents, and young adults; (2) musculo-skeletal changes in the growing athlete; (3) epiphyseal injuries and their potential for resulting in temporary or permanent impairment; (4)…

  16. Human torque velocity adaptations to sprint, endurance, or combined modes of training

    NASA Technical Reports Server (NTRS)

    Shealy, M. J.; Callister, R.; Dudley, G. A.; Fleck, S. J.

    1992-01-01

    We had groups of athletes perform sprint and endurance run training independently or concurrently for 8 weeks to examine the voluntary in vivo mechanical responses to each type of training. Pre- and posttraining angle-specific peak torque during knee extension and flexion were determined at 0, 0.84, 1.65, 2.51, 3.35, 4.19, and 5.03 radian.sec-1 and normalized for lean body mass. Knee extension torque in the sprint-trained group increased across all test velocities, the endurance-trained group increased at 2.51, 3.34, 4.19, and 5.03 radian.sec-1, and the group performing the combined training showed no change at any velocity. Knee flexion torque of the sprint and combined groups decreased at 0.84, 1.65, and 2.51 radian.sec-1. Knee flexion torque in the sprint-trained group also decreased at 0 radian.sec-1 and in the combined group at 3.34 radian.sec-1. Knee flexion torque in the endurance-trained group showed no change at any velocity of contraction. Mean knee flexion:extension ratios across the test velocities significantly decreased in the sprint-trained group. Knee extension endurance during 30 seconds of maximal contractions significantly increased in all groups. Only the sprint-trained group showed a significant increase in endurance of the knee flexors. These data suggest that changes in the voluntary in vivo mechanical characteristics of knee extensor and flexor skeletal muscles are specific to the type of run training performed.

  17. Voluntary fluid intake, hydration status, and aerobic performance of adolescent athletes in the heat.

    PubMed

    Wilk, Boguslaw; Timmons, Brian W; Bar-Or, Oded

    2010-12-01

    We determined whether beverage flavoring and composition would stimulate voluntary drink intake, prevent dehydration, and maintain exercise performance in heat-acclimated adolescent males running in the heat. Eight adolescent (age, 13.7 ± 1.1 years) runners (peak oxygen uptake, 59.5 ± 4.0 mL·kg-1·min-1) underwent at least four 80-min exercise heat-acclimation sessions before completing 3 experimental sessions. All sessions were performed at 30 °C and 60%-65% relative humidity. Each experimental session consisted of five 15-min treadmill runs at a speed eliciting 65% peak oxygen uptake, with a 5 min rest prior to each run. Ten minutes after the final run, a time to exhaustion test was performed at a speed eliciting 90% peak oxygen uptake. Counterbalanced experimental sessions were identical, except for fluid intake, which consisted of tap water (W), flavored water (FW), and FW with 6% carbohydrate and 18 mmol·L-1 NaCl (CNa) consumed ad libitum. Fluid intake and body weight were monitored to calculate dehydration. Voluntary fluid intake was similar to fluid losses in W (1032 ± 130 vs. 1340 ± 246 g), FW (1086 ± 86 vs. 1451 ± 253 g), and CNa (1259 ± 119 vs. 1358 ± 234 g). As a result, significant dehydration was avoided in all trials (-0.45% ± 0.68% body weight in W, -0.66% ± 0.50% body weight in FW, and -0.13% ± 0.71% body weight in CNa). Core temperature increased by ~1 °C during exercise, but was not different between trials. Time to exhaustion was not different between trials and averaged 8.8 ± 1.7 min. Under exercise conditions more closely reflecting real-life situations, heat-acclimatized adolescent male runners can appropriately gauge fluid intake regardless of the type of beverage made available, resulting in consistency in exercise performance. PMID:21164555

  18. The child and adolescent athlete: a review of three potentially serious injuries

    PubMed Central

    2014-01-01

    The increased participation of children and adolescents in organized sports worldwide is a welcome trend given evidence of lower physical fitness and increased prevalence of overweight in this population. However, the increased sports activity of children from an early age and continued through the years of growth, against a background of their unique vulnerability to injury, gives rise to concern about the risk and severity of injury. Three types of injury–anterior cruciate ligament (ACL) injury, concussion, and physeal injury – are considered potentially serious given their frequency, potential for adverse long-term health outcomes, and escalating healthcare costs. Concussion is probably the hottest topic in sports injury currently with voracious media coverage and exploding research interest. Given the negative cognitive effects of concussion, it has the potential to have a great impact on children and adolescents during their formative years and potentially impair school achievement and, if concussion management is not managed appropriately, there can be long term negative impact on cognitive development and ability to resume sports participation. Sudden and gradual onset physeal injury is a unique injury to the pediatric population which can adversely affect growth if not managed correctly. Although data are lacking, the frequency of stress-related physeal injury appears to be increasing. If mismanaged, physeal injuries can also lead to long-term complications which could negatively affect ability to participate in sports. Management of ACL injuries is an area of controversy and if not managed appropriately, can affect long-term growth and recovery as well as the ability to participate in sports. This article considers the young athlete’s vulnerability to injury, with special reference to ACL injury, concussion, and physeal injury, and reviews current research on epidemiology, diagnosis, treatment, and prevention of these injury types. This article is

  19. Muscle coordination changes during intermittent cycling sprints.

    PubMed

    Billaut, François; Basset, Fabien A; Falgairette, Guy

    2005-06-01

    Maximal muscle power is reported to decrease during explosive cyclical exercises owing to metabolic disturbances, muscle damage, and adjustments in the efferent neural command. The aim of the present study was to analyze the influence of inter-muscle coordination in fatigue occurrence during 10 intermittent 6-s cycling sprints, with 30-s recovery through electromyographic activity (EMG). Results showed a decrease in peak power output with sprint repetitions (sprint 1 versus sprint 10: -11%, P<0.01) without any significant modifications in the integrated EMG. The timing between the knee extensor and the flexor EMG activation onsets was reduced in sprint 10 (sprint 1 versus sprint 10: -90.2 ms, P<0.05), owing to an earlier antagonist activation with fatigue occurrence. In conclusion, the maximal power output, developed during intermittent cycling sprints of short duration, decreased possibly due to the inability of muscles to maintain maximal force. This reduction in maximal power output occurred in parallel to changes in the muscle coordination pattern after fatigue. PMID:15862899

  20. What Research Tells the Coach About Sprinting.

    ERIC Educational Resources Information Center

    Dintiman, George B.

    This booklet on sprinting is divided into four chapters. Chapter 1 "Introduction," provides an analysis of the 100-meter dash, summarizes world records, and discusses the reliability of timing the sprint race. Chapter 2, "Describing the Sprinter," discusses the following topics: anatomical characteristics, flexibility, reaction, strength/power,…

  1. The force, power, and energy of the 100 meter sprint

    NASA Astrophysics Data System (ADS)

    Helene, O.; Yamashita, M. T.

    2010-03-01

    At the 2008 Summer Olympics in Beijing, Usain Bolt broke the world record for the 100 m sprint. Just one year later, at the 2009 World Championships in Athletics in Berlin he broke it again. A few months after Beijing, Eriksen et al. [Am. J. Phys. 77, 224-228 (2009)] studied Bolt's performance and predicted that Bolt could have run about one-tenth of a second faster, which was confirmed in Berlin. In this paper we extend the analysis of Eriksen et al. to model Bolt's velocity time dependence for the Beijing 2008 and Berlin 2009 records. We deduce the maximum force, the maximum power, and the total mechanical energy produced by Bolt in both races. Surprisingly, we conclude that all of these values were smaller in 2009 than in 2008.

  2. Comparison of Effect of Regular Unstructured Physical Training and Athletic Level Training on Body Composition and Cardio Respiratory Fitness in Adolescents

    PubMed Central

    Subramanian, Senthil Kumar; Sharma, Vivek Kumar; A, Vinayathan

    2013-01-01

    Background: Childhood obesity and hypertension are global problems that are on the rise in India. Improving physical activity is an accepted main line of strategy for overcoming poor body composition, hypertension and reduced cardio respiratory fitness (CRF) all of which are considered as independent risk factors for the development of future cardiovascular complications. Aim: Present study was conducted to evaluate the effect of regular unstructured physical training and athletic level training on anthropometric measures, body composition, blood pressure and cardio respiratory fitness in adolescents. Settings and Design: This is a collaborative study between the Department of physiology, Jawaharlal Institute of Postgraduate Medical Education and Research and Residential school, Jawahar Navodhya Vidyalaya, Puducherry, India. Method and Material: Student volunteers in the age group of 12–17 years were classified into athletes (group 1) and physically active non-athletes (group 2). Parameters measured and calculated were weight, height, body mass index, waist and hip circumference, body fat percentage (BF%), fat free mass (FFM), Systolic (SBP) & Diastolic blood pressure (DBP), Mean arterial pressure (MAP), Rate pressure product (RPP) and Predicted VO2 max. Statistical Analysis used: Mean difference between the groups was analysed using unpaired Student’s t–test. All statistical analysis was carried out for two-tailed significance at the 5 % level using SPSS version 19 (SPSSInc, USA). Results: Anthropometric measures, body composition measures and blood pressure values of both the group students were within the normal limits. There was no significant difference in anthropometric and body composition parameters between the group 1 and group 2 students. DBP, MAP and RPP were significantly lower in group 1 students when compared to group 2 students. VO2 max values were more in group 1 girls as compared to group 2 girls while the values of boys were comparable

  3. Metatarsophalangeal joint function during sprinting: a comparison of barefoot and sprint spike shod foot conditions.

    PubMed

    Smith, Grace; Lake, Mark; Lees, Adrian

    2014-04-01

    The metatarsophalangeal joint is an important contributor to lower limb energetics during sprint running. This study compared the kinematics, kinetics and energetics of the metatarsophalangeal joint during sprinting barefoot and wearing standardized sprint spikes. The aim of this investigation was to determine whether standard sprinting footwear alters the natural motion and function of the metatarsophalangeal joint exhibited during barefoot sprint running. Eight trained sprinters performed maximal sprints along a runway, four sprints in each condition. Three-dimensional high-speed (1000 Hz) kinematic and kinetic data were collected at the 20 m point. Joint angle, angular velocity, moment, power and energy were calculated for the metatarsophalangeal joint. Sprint spikes significantly increase sprinting velocity (0.3 m/s average increase), yet limit the range of motion about the metatarsophalangeal joint (17.9% average reduction) and reduce peak dorsiflexion velocity (25.5% average reduction), thus exhibiting a controlling affect over the natural behavior of the foot. However, sprint spikes improve metatarsophalangeal joint kinetics by significantly increasing the peak metatarsophalangeal joint moment (15% average increase) and total energy generated during the important push-off phase (0.5 J to 1.4 J). The results demonstrate substantial changes in metatarsophalangeal function and potential improvements in performance-related parameters due to footwear. PMID:24042098

  4. Approach to the Underperforming Athlete.

    PubMed

    Solomon, Mary L; Weiss Kelly, Amanda K

    2016-03-01

    Children and adolescents who participate in intense sports training may face physical and psychologic stresses. The pediatric health care provider can play an important role in monitoring an athlete's preparation by obtaining a proper sports history, assessing sleep hygiene, discussing nutrition and hydration guidelines, and evaluating physiologic causes of fatigue. Educating parents and athletes on the potential risks of high-intensity training, inadequate rest and sleep, and a poor diet may improve the athlete's performance and prevent symptoms of overtraining syndrome. Infectious mononucleosis must also be considered a cause of fatigue among adolescents. The signs and symptoms of overtraining and burnout are discussed in this article. PMID:27031317

  5. Spondyloptosis in athlete.

    PubMed

    Assad, Ana Paula Luppino; Abreu, Andressa Silva; Seguro, Luciana Parente Costa; Guedes, Lissiane Karine Noronha; Lima, Fernanda Rodrigues; Pinto, Ana Lucia de Sá

    2014-01-01

    The adolescent athletes are at greater risk of low back pain and structural spine injuries. Spondylolysis is responsible for the majority of back pain cases in young athletes, rarely occurring in adults. We report a case of a 13-year-old judo female athlete, who came to our service with 5 months of progressive low back pain during training which was initially attributed to mechanical causes, without any further investigation by imaging methods. At admission, the patient had lumbar deformity, antalgic posture and bilaterally positive unipodalic lumbar hyperextension maneuver. After a research which showed spondyloptosis, the patient underwent surgery. In this article, we discuss, based on this case report, the diagnostic approach to low back pain in young athletes, since the complaint of chronic back pain can be a marker of a structural lesion that may be permanent and bring irreversible functional loss. PMID:25054602

  6. Athlete's Foot

    MedlinePlus

    ... Home » Learn About Feet » Foot Health Information Athlete's Foot What is Athlete's Foot? Athlete's foot is a skin disease caused by a fungus, ... fungus growth. Not all fungus conditions are athlete's foot. Other conditions, such as disturbances of the sweat ...

  7. On the performance of Usain Bolt in the 100 m sprint

    NASA Astrophysics Data System (ADS)

    Hernández Gómez, J. J.; Marquina, V.; Gómez, R. W.

    2013-09-01

    Many university texts on mechanics consider the effect of air drag force, using the slowing down of a parachute as an example. Very few discuss what happens when the drag force is proportional to both u and u2. In this paper we deal with a real problem to illustrate the effect of both terms on the speed of a runner: a theoretical model of the world-record 100 m sprint of Usain Bolt during the 2009 World Championships in Berlin is developed, assuming a drag force proportional to u and to u2. The resulting equation of motion is solved and fitted to the experimental data obtained from the International Association of Athletics Federations, which recorded Bolt's position with a laser velocity guard device. It is worth noting that our model works only for short sprints.

  8. Genes for elite power and sprint performance: ACTN3 leads the way.

    PubMed

    Eynon, Nir; Hanson, Erik D; Lucia, Alejandro; Houweling, Peter J; Garton, Fleur; North, Kathryn N; Bishop, David J

    2013-09-01

    The ability of skeletal muscles to produce force at a high velocity, which is crucial for success in power and sprint performance, is strongly influenced by genetics and without the appropriate genetic make-up, an individual reduces his/her chances of becoming an exceptional power or sprinter athlete. Several genetic variants (i.e. polymorphisms) have been associated with elite power and sprint performance in the last few years and the current paradigm is that elite performance is a polygenic trait, with minor contributions of each variant to the unique athletic phenotype. The purpose of this review is to summarize the specific knowledge in the field of genetics and elite power performance, and to provide some future directions for research in this field. Of the polymorphisms associated with elite power and sprint performance, the α-actinin-3 R577X polymorphism provides the most consistent results. ACTN3 is the only gene that shows a genotype and performance association across multiple cohorts of elite power athletes, and this association is strongly supported by mechanistic data from an Actn3 knockout mouse model. The angiotensin-1 converting enzyme insertion/deletion polymorphism (ACE I/D, registered single nucleotide polymorphism [rs]4646994), angiotensinogen (AGT Met235Thr rs699), skeletal adenosine monophosphate deaminase (AMPD1) Gln(Q)12Ter(X) [also termed C34T, rs17602729], interleukin-6 (IL-6 -174 G/C, rs1800795), endothelial nitric oxide synthase 3 (NOS3 -786 T/C, rs2070744; and Glu298Asp, rs1799983), peroxisome proliferator-activated receptor-α (PPARA Intron 7 G/C, rs4253778), and mitochondrial uncoupling protein 2 (UCP2 Ala55Val, rs660339) polymorphisms have also been associated with elite power performance, but the findings are less consistent. In general, research into the genetics of athletic performance is limited by a small sample size in individual studies and the heterogeneity of study samples, often including athletes from multiple

  9. A Split Sprint mission to Mars

    NASA Astrophysics Data System (ADS)

    Shepard, Kyle; Duffey, Jack; D'Annible, Dom; Holdridge, Jeff; Thompson, Walter; Armstrong, Robert C.

    1992-01-01

    Comprehensive infrastructure analysis is central to developing architectures necessary to support the Space Exploration Initiative. In the ``Split Sprint'' architecture, the cargo is split from the crew. An efficient low thrust ``slow boat'' is used for the cargo and a high thrust ``sprint'' vehicle is used for the crew. Infrastructure analysis is utilized in developing initial element designs to meet the transportation system requirements of the slit sprint architecture. Infrastructure analysis considers technology availability, launch vehicle volume and lift requirements, on orbit assembly, trajectory design and optimization, system reduncancy requirements and evolutionary capability. The resulting infrastructure includes propulsion system options for the crew and cargo space transfer vehicles. For the cargo, an SP-100 derived nuclear electric propulsion system was developed. For the crew, either a conventional cryogenic (LO2/LH2) propulsion system or nuclear thermal propulsion system is utilized. It is shown that the split sprint mission competes effectively with conventional approaches to the Mars mission.

  10. Regression models of sprint, vertical jump, and change of direction performance.

    PubMed

    Swinton, Paul A; Lloyd, Ray; Keogh, Justin W L; Agouris, Ioannis; Stewart, Arthur D

    2014-07-01

    It was the aim of the present study to expand on previous correlation analyses that have attempted to identify factors that influence performance of jumping, sprinting, and changing direction. This was achieved by using a regression approach to obtain linear models that combined anthropometric, strength, and other biomechanical variables. Thirty rugby union players participated in the study (age: 24.2 ± 3.9 years; stature: 181.2 ± 6.6 cm; mass: 94.2 ± 11.1 kg). The athletes' ability to sprint, jump, and change direction was assessed using a 30-m sprint, vertical jump, and 505 agility test, respectively. Regression variables were collected during maximum strength tests (1 repetition maximum [1RM] deadlift and squat) and performance of fast velocity resistance exercises (deadlift and jump squat) using submaximum loads (10-70% 1RM). Force, velocity, power, and rate of force development (RFD) values were measured during fast velocity exercises with the greatest values produced across loads selected for further analysis. Anthropometric data, including lengths, widths, and girths were collected using a 3-dimensional body scanner. Potential regression variables were first identified using correlation analyses. Suitable variables were then regressed using a best subsets approach. Three factor models generally provided the most appropriate balance between explained variance and model complexity. Adjusted R values of 0.86, 0.82, and 0.67 were obtained for sprint, jump, and change of direction performance, respectively. Anthropometric measurements did not feature in any of the top models because of their strong association with body mass. For each performance measure, variance was best explained by relative maximum strength. Improvements in models were then obtained by including velocity and power values for jumping and sprinting performance, and by including RFD values for change of direction performance. PMID:24345969

  11. Stress fractures in athletes.

    PubMed

    Hulkko, A; Orava, S

    1987-06-01

    During the 14-year period of 1971-1985, 368 stress fractures in 324 athletes were treated. The series contained 268 fractures in males and 100 fractures in females; 32 fractures occurred in children (less than 16 years), 117 in adolescents (16-19 years), and 219 in adults. Forty-six fractures were incurred by athletes at an international level, 274 by athletes at a national or district level and 48 by recreational athletes. Of the total cases, 72% occurred to runners and a further 12% to athletes in other sports after running exercises. The distribution of the stress fractures by site was: tibia 182, metatarsal bones 73, fibula 44, big toe sesamoid bones 15, femoral shaft 14, femoral neck 9, tarsal navicular 9, pelvis 7, olecranon 5 and other bones 10. Of the total fractures, 342 were treated conservatively and 26 fractures required surgical treatment. The operative indication was dislocation in 5 cases and delayed union/nonunion in 21 cases. The sites most often affected by delayed union were: anterior midtibia, sesamoid bones of the big toe, base of the fifth metatarsal, olecranon, and tarsal navicular. The athletes at an international level experienced the greatest risk of multiple separate fractures, protracted healing, or fractures requiring surgery. PMID:3623785

  12. The Prevalence of Obesity and Elevated Blood Pressure in Adolescent Student Athletes From the State of Mississippi

    PubMed Central

    Stiefel, Eric C.; Field, Larry; Replogle, William; McIntyre, Louis; Igboechi, Oduche; Savoie, Felix H.

    2016-01-01

    Background: Over the past 30 years, there has been a dramatic increase in the prevalence of childhood obesity and hypertension in the United States. The prevalence of these diagnoses among individuals participating in school-sanctioned sports has not been clearly defined. Purpose: To identify the prevalence of obesity and elevated blood pressure (BP) among student athletes and investigate associations between race, sex, type and number of sports played, and the prevalence of these diseases. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Pre–sports participation medical examinations (N = 7705) performed between 2009 and 2013 were reviewed to identify the prevalence of obesity and elevated BP and examine relationships between the type of sports played, participation in multiple sports versus a single sport, and the athlete’s body weight and body mass index (BMI). Results: The prevalence of obesity was 23.5%. There was a significant association (P < .001) between the number of sports played by the student and BMI. The risk of obesity among single-sport athletes was more than 2-fold the risk (relative risk [RR], 2.13) compared with ≥3-sport athletes and 1.42 times greater compared with 2-sport athletes (RR, 1.42). The prevalence of elevated BP was 21.2%. There was a significant association (P < .001) between the number of sports played by the student and elevated BP. The risk of elevated BP among single-sport athletes was 1.59 times greater (RR, 1.59) than ≥3-sport athletes and 1.30 times greater compared with 2-sport athletes (RR, 1.30). Finally, obese students were 2.40 times more likely to have elevated BP compared with nonobese students (P < .001). Conclusion: The result of this study confirms the progressive nature of the obesity epidemic and identifies the contribution of obesity to the worsening cardiometabolic profiles in student athletes. The study also identifies that participation in multiple sports and running sports decreases

  13. Athlete's Foot

    MedlinePlus

    Athlete's foot is a common infection caused by a fungus. It most often affects the space between the toes. ... skin between your toes. You can get athlete's foot from damp surfaces, such as showers, swimming pools, ...

  14. Athlete's Foot

    MedlinePlus

    ... type of tinea, athlete's foot. The Basics on Tinea Infections Tinea (pronounced: TIH-nee-uh) is the medical name ... or scalp, including athlete's foot, jock itch , and ringworm (despite its name, ringworm is not a worm). ...

  15. A novel compression garment with adhesive silicone stripes improves repeated sprint performance – a multi-experimental approach on the underlying mechanisms

    PubMed Central

    2014-01-01

    Background Repeated sprint performance is determined by explosive production of power, as well as rapid recovery between successive sprints, and there is evidence that compression garments and sports taping can improve both of these factors. Methods In each of two sub-studies, female athletes performed two sets of 30 30-m sprints (one sprint per minute), one set wearing compression garment with adhesive silicone stripes (CGSS) intended to mimic taping and the other with normal clothing, in randomized order. Sub-study 1 (n = 12) focused on cardio-respiratory, metabolic, hemodynamic and perceptual responses, while neuronal and biomechanical parameters were examined in sub-study 2 (n = 12). Results In both sub-studies the CGSS improved repeated sprint performance during the final 10 sprints (best P < 0.01, d = 0.61). None of the cardio-respiratory or metabolic variables monitored were altered by wearing this garment (best P = 0.06, d = 0.71). Also during the final 10 sprints, rating of perceived exertion by the upper leg muscles was reduced (P = 0.01, d = 1.1), step length increased (P = 0.01, d = 0.91) and activation of the m. rectus femoris elevated (P = 0.01, d = 1.24), while the hip flexion angle was lowered throughout the protocol (best P < 0.01, d = 2.28) and step frequency (best P = 0.34, d = 0.2) remained unaltered. Conclusion Although the physiological parameters monitored were unchanged, the CGSS appears to improve performance during 30 30-m repeated sprints by reducing perceived exertion and altering running technique. PMID:24914412

  16. Heat acclimation improves intermittent sprinting in the heat but additional pre-cooling offers no further ergogenic effect.

    PubMed

    Castle, Paul; Mackenzie, Richard W; Maxwell, Neil; Webborn, Anthony D J; Watt, Peter W

    2011-08-01

    The aim of this study was to determine the effect of 10 days of heat acclimation with and without pre-cooling on intermittent sprint exercise performance in the heat. Eight males completed three intermittent cycling sprint protocols before and after 10 days of heat acclimation. Before acclimation, one sprint protocol was conducted in control conditions (21.8 ± 2.2°C, 42.8 ± 6.7% relative humidity) and two sprint protocols in hot, humid conditions (33.3 ± 0.6°C, 52.2 ± 6.8% relative humidity) in a randomized order. One hot, humid condition was preceded by 20 min of thigh pre-cooling with ice packs (-16.2 ± 4.5°C). After heat acclimation, the two hot, humid sprint protocols were repeated. Before heat acclimation, peak power output declined in the heat (P < 0.05) but pre-cooling prevented this. Ten days of heat acclimation reduced resting rectal temperature from 37.8 ± 0.3°C to 37.4 ± 0.3°C (P < 0.01). When acclimated, peak power output increased by ∼2% (P < 0.05, main effect) and no reductions in individual sprint peak power output were observed. Additional pre-cooling offered no further ergogenic effect. Unacclimated athletes competing in the heat should pre-cool to prevent reductions in peak power output, but heat acclimate for an increased peak power output. PMID:21777052

  17. Overall view from south to north of remote sprint launch ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overall view from south to north of remote sprint launch sprint launch site #3. Remote launch operations building on left, exclusion area sentry station at distant center, and limited area sentry station on right - Stanley R. Mickelsen Safeguard Complex, Remote Sprint Launch Site No. 3, North of State Route 5, approximately 10 miles Southwest of Walhalla, ND, Nekoma, Cavalier County, ND

  18. Psychological Characteristics of Adolescent Steroid Users.

    ERIC Educational Resources Information Center

    Burnett, Kent F.; Kleiman, Mark E.

    1994-01-01

    Used Millon Adolescent Personality Inventory and Profile of Mood States to assess psychological characteristics in 72 adolescent males: 24 adolescent athletes who reported steroid use, 24 athletes with no steroid use, and 24 nonathletes. Although some personality variables differentiated between athletes and nonathletes, no personality variables…

  19. Pars Injuries in Athletes.

    PubMed

    Oren, Jonathan H; Gallina, Jason M

    2016-03-01

    Pars injuries are common causes of low back pain in adolescent athletes. Workup traditionally has included lumbar radiographs with oblique views and single-photon emission computed tomography (SPECT). However, recent literature has demonstrated the accuracy of MRI as a diagnostic modality. Acute injuries may be amenable to bracing with the goal of a healed lesion. Most cases of spondylolysis will result in asymptomatic non-union, though pars repair is an option for symptomatic pars defects without spondylolisthesis. PMID:26977552

  20. Physiological and Neuromuscular Response to a Simulated Sprint-Distance Triathlon: Effect of Age Differences and Ability Level.

    PubMed

    García-Pinillos, Felipe; Cámara-Pérez, José C; González-Fernández, Francisco T; Párraga-Montilla, Juan A; Muñoz-Jiménez, Marcos; Latorre-Román, Pedro Á

    2016-04-01

    García-Pinillos, F, Cámara-Pérez, JC, González-Fernández, FT, Párraga-Montilla, JA, Muñoz-Jiménez, M, and Latorre-Román, PÁ. Physiological and neuromuscular response to a simulated sprint-distance triathlon: effect of age differences and ability level. J Strength Cond Res 30(4): 1077-1084, 2016-This study aimed to describe the acute impact of a simulated sprint-distance triathlon at physiological and neuromuscular levels and to determine whether age and athletic performance influenced the response in triathletes. Nineteen triathletes performed a sprint-distance triathlon under simulated conditions. Cardiovascular response was monitored during the race. Rate of perceived exertion along with muscular performance parameters (countermovement jump [CMJ], squat jump [SJ], and handgrip strength test [HS]) were tested at pre- and posttest and during every transition, while a 20-m sprint test (S20m) was performed before and after the race. Blood lactate was recorded postrace. A repeated measures analysis of variance showed that the neuromuscular response-in terms of CMJ, SJ, and HS-was unchanged (p ≥ 0.05), while S20m performance was impaired at posttest (p < 0.001). A linear regression analysis showed that ΔCMJ predicted the overall race time (R = 0.226; p = 0.046). In addition, 2 cluster analyses (k-means) were performed by grouping according to athletic performance and age. Between-group comparison showed no significant differences in the impact of the race at either the physiological or the neuromuscular level. The results showed that muscular performance parameters were not impaired throughout the race despite high levels of fatigue reported. However, despite maintaining initial levels of muscle force after the race, the fatigue-induced changes in S20m were significant, which could reinforce the need to train sprint ability in endurance athletes. Finally, despite the differences in ability level or in age, the acute physiological and neuromuscular

  1. Effects of Strength Training on Squat and Sprint Performance in Soccer Players.

    PubMed

    Styles, William J; Matthews, Martyn J; Comfort, Paul

    2016-06-01

    Styles, WJ, Matthews, MJ, and Comfort, P. Effects of strength training on squat and sprint performance in soccer players. J Strength Cond Res 30(6): 1534-1539, 2016-Researchers have demonstrated that increases in strength result in increases in athletic performance, although the development of strength is still neglected in some sports. Our aim was to determine whether a simple in-season strength training program would result in increases in maximal squat strength and short sprint performance, in professional soccer players. Professional soccer players (n = 17, age = 18.3 ± 1.2 years, height = 1.79 ± 0.06 m, body mass [BM] = 75.5 ± 6.1 kg) completed 1 repetition maximum (1RM) back squat and sprint tests (5, 10, and 20 m) before and after a 6-week (×2 week) in-season strength training (85-90% 1RM) intervention. Strength training resulted in significant improvements in absolute and relative strength (before = 125.4 ± 13.8 kg, after = 149.3 ± 16.2 kg, p ≤ 0.001, Cohen's d = 0.62; 1RM/BM before: 1.66 ± 0.24 kg·kg, after = 1.96 ± 0.29 kg·kg, p ≤ 0.001, Cohen's d = 0.45; respectively). Similarly, there were small yet significant improvements in sprint performance over 5 m (before = 1.11 ± 0.04 seconds, after = 1.05 ± 0.05 seconds, p ≤ 0.001, Cohen's d = 0.55), 10 m (before = 1.83 ± 0.05 seconds, after = 1.78 ± 0.05 seconds, p ≤ 0.001, Cohen's d = 0.45), and 20 m (before = 3.09 ± 0.07 seconds, after = 3.05 ± 0.05 seconds, p ≤ 0.001, Cohen's d = 0.31). Changes in maximal squat strength seem to be reflected in improvements in short sprint performance highlighting the importance of developing maximal strength to improve short sprint performance. Moreover, this demonstrates that these improvements can be achieved during the competitive season in professional soccer players. PMID:26473518

  2. CONSERVATIVE MANAGEMENT OF AN ISOLATED GRADE III LATERAL COLLATERAL LIGAMENT INJURY IN AN ADOLESCENT MULTI-SPORT ATHLETE: A CASE REPORT

    PubMed Central

    Haddad, M. Alex; Budich, Justin M.; Eckenrode, Brian J.

    2016-01-01

    ABSTRACT Study design Case report Background Isolated, grade III lateral collateral ligament knee injuries are an uncommon traumatic injury with little guidance available in the literature for conservative management and prognosis for return to sport. The purpose of this case report is to describe the clinical decision-making in both differential diagnosis and physical therapy management of an isolated grade III lateral collateral ligament sprain in an adolescent multi-sport high school athlete. Case Description A 16 year-old male, high school, multi-sport athlete (cross country, wrestling, track and field) sustained a traumatic knee injury during a wrestling match when his involved lower extremity was forcefully externally rotated by his opponent. Initial clinical presentation revealed pain and increased laxity with varus stress testing of the left knee, which was subsequently identified via MRI as a complete lateral collateral ligament rupture (grade III). A conservative physical therapy program was developed targeting the active and neuromuscular subsystems, theorized to compensate for the lack of an intact lateral collateral ligament. Outcomes The subject attended 18 visits of physical therapy over a period of 12 weeks. His rehabilitation program focused on functional strengthening of the posterolateral corner, enhancement of neuromuscular control, and graded progression to sports specific drills. Return to play decisions were based on a combination of lower extremity functional performance measures, condition specific outcome measures and subjective performance on sports specific tasks. At discharge from physical therapy, he reported 0/10 pain, scored a 76/80 on the Lower Extremity Functional Scale, and was able to return to competitive track and field events. Discussion Few descriptions in the literature exist for the conservative management of isolated, grade III lateral collateral ligament injuries. A program of selective functional strengthening

  3. Pre-exposure to hyperoxic air does not enhance power output during subsequent sprint cycling.

    PubMed

    Sperlich, Billy; Schiffer, Thorsten; Achtzehn, Silvia; Mester, Joachim; Holmberg, Hans-Christer

    2010-09-01

    Previous studies have indicated that aerobic pathways contribute to 13-27% of the energy consumed during short-term (10-20 s) sprinting exercise. Accordingly, the present investigation was designed to test the hypothesis that prior breathing of oxygen-enriched air (F(in)O(2) = 60%) would enhance power output and reduce fatigue during subsequent sprint cycling. Ten well-trained male cyclists (mean +/- SD age, 25 +/- 3 years; height, 186.1 +/- 6.9 cm; body mass, 79.1 +/- 8.2 kg; maximal oxygen uptake [VO(2max)]: 63.2 +/- 5.2 ml kg(-1) min(-1)) took 25 breaths of either hyperoxic (HO) or normoxic (NO) air before performing 15 s of cycling at maximal exertion. During this performance, the maximal and mean power outputs were recorded. The concentration of lactate, pH, partial pressure of and saturation by oxygen, [H(+)] and base excess in arterial blood were assessed before and after the sprint. The maximal (1,053 +/- 141 for HO vs. 1,052 +/- 165 W for NO; P = 0.77) and mean power outputs (873 +/- 123 vs. 876 +/- 147 W; P = 0.68) did not differ between the two conditions. The partial pressure of oxygen was approximately 2.3-fold higher after inhaling HO in comparison to NO, while lactate concentration, pH, [H(+)] and base excess (best P = 0.32) after sprinting were not influenced by exposure to HO. These findings demonstrate that the peak and mean power outputs of athletes performing short-term intense exercise cannot be improved by pre-exposure to oxygen-enriched air. PMID:20473681

  4. Field monitoring of sprinting power-force-velocity profile before, during and after hamstring injury: two case reports.

    PubMed

    Mendiguchia, J; Edouard, P; Samozino, P; Brughelli, M; Cross, M; Ross, A; Gill, N; Morin, J B

    2016-01-01

    Very little is currently known about the effects of acute hamstring injury on over-ground sprinting mechanics. The aim of this research was to describe changes in power-force-velocity properties of sprinting in two injury case studies related to hamstring strain management: Case 1: during a repeated sprint task (10 sprints of 40 m) when an injury occurred (5th sprint) in a professional rugby player; and Case 2: prior to (8 days) and after (33 days) an acute hamstring injury in a professional soccer player. A sports radar system was used to measure instantaneous velocity-time data, from which individual mechanical profiles were derived using a recently validated method based on a macroscopic biomechanical model. Variables of interest included: maximum theoretical velocity (V0) and horizontal force (F(H0)), slope of the force-velocity (F-v) relationship, maximal power, and split times over 5 and 20 m. For Case 1, during the injury sprint (sprint 5), there was a clear change in the F-v profile with a 14% greater value of F(H0) (7.6-8.7 N/kg) and a 6% decrease in V0 (10.1 to 9.5 m/s). For Case 2, at return to sport, the F-v profile clearly changed with a 20.5% lower value of F(H0) (8.3 vs. 6.6 N/kg) and no change in V0. The results suggest that the capability to produce horizontal force at low speed (F(H0)) (i.e. first metres of the acceleration phase) is altered both before and after return to sport from a hamstring injury in these two elite athletes with little or no change of maximal velocity capabilities (V0), as evidenced in on-field conditions. Practitioners should consider regularly monitoring horizontal force production during sprint running both from a performance and injury prevention perspective. PMID:26648237

  5. Hang cleans and hang snatches produce similar improvements in female collegiate athletes

    PubMed Central

    Ayers, JL; DeBeliso, M; Sevene, TG

    2016-01-01

    Olympic weightlifting movements and their variations are believed to be among the most effective ways to improve power, strength, and speed in athletes. This study investigated the effects of two Olympic weightlifting variations (hang cleans and hang snatches), on power (vertical jump height), strength (1RM back squat), and speed (40-yard sprint) in female collegiate athletes. 23 NCAA Division I female athletes were randomly assigned to either a hang clean group or hang snatch group. Athletes participated in two workout sessions a week for six weeks, performing either hang cleans or hang snatches for five sets of three repetitions with a load of 80-85% 1RM, concurrent with their existing, season-specific, resistance training program. Vertical jump height, 1RM back squat, and 40-yard sprint all had a significant, positive improvement from pre-training to post-training in both groups (p≤0.01). However, when comparing the gain scores between groups, there was no significant difference between the hang clean and hang snatch groups for any of the three dependent variables (i.e., vertical jump height, p=0.46; 1RM back squat, p=0.20; and 40-yard sprint, p=0.46). Short-term training emphasizing hang cleans or hang snatches produced similar improvements in power, strength, and speed in female collegiate athletes. This provides strength and conditioning professionals with two viable programmatic options in athletic-based exercises to improve power, strength, and speed. PMID:27601779

  6. Hang cleans and hang snatches produce similar improvements in female collegiate athletes.

    PubMed

    Ayers, J L; DeBeliso, M; Sevene, T G; Adams, K J

    2016-09-01

    Olympic weightlifting movements and their variations are believed to be among the most effective ways to improve power, strength, and speed in athletes. This study investigated the effects of two Olympic weightlifting variations (hang cleans and hang snatches), on power (vertical jump height), strength (1RM back squat), and speed (40-yard sprint) in female collegiate athletes. 23 NCAA Division I female athletes were randomly assigned to either a hang clean group or hang snatch group. Athletes participated in two workout sessions a week for six weeks, performing either hang cleans or hang snatches for five sets of three repetitions with a load of 80-85% 1RM, concurrent with their existing, season-specific, resistance training program. Vertical jump height, 1RM back squat, and 40-yard sprint all had a significant, positive improvement from pre-training to post-training in both groups (p≤0.01). However, when comparing the gain scores between groups, there was no significant difference between the hang clean and hang snatch groups for any of the three dependent variables (i.e., vertical jump height, p=0.46; 1RM back squat, p=0.20; and 40-yard sprint, p=0.46). Short-term training emphasizing hang cleans or hang snatches produced similar improvements in power, strength, and speed in female collegiate athletes. This provides strength and conditioning professionals with two viable programmatic options in athletic-based exercises to improve power, strength, and speed. PMID:27601779

  7. Interpreting SPRINT: How low should you go?

    PubMed

    Thomas, George; Nally, Joseph V; Pohl, Marc A

    2016-03-01

    The Systolic Blood Pressure Intervention Trial (SPRINT) found evidence of cardiovascular benefit with intensive lowering of systolic blood pressure (goal < 120 mm Hg) compared with the currently recommended goal (< 140 mm Hg) in older patients with cardiovascular risk but without diabetes or stroke. This article reviews the trial design and protocol, summarizes the results, and briefly discusses the implications of these results. PMID:26974989

  8. Two-Dimensional Video Analysis of Youth and Adolescent Pitching Biomechanics: A Tool For the Common Athlete.

    PubMed

    DeFroda, Steven F; Thigpen, Charles A; Kriz, Peter K

    2016-01-01

    Three-dimensional (3D) motion analysis is the gold standard for analyzing the biomechanics of the baseball pitching motion. Historically, 3D analysis has been available primarily to elite athletes, requiring advanced cameras, and sophisticated facilities with expensive software. The advent of newer technology, and increased affordability of video recording devices, and smartphone/tablet-based applications has led to increased access to this technology for youth/amateur athletes and sports medicine professionals. Two-dimensional (2D) video analysis is an emerging tool for the kinematic assessment and observational measurement of pitching biomechanics. It is important for providers, coaches, and players to be aware of this technology, its application in identifying causes of arm pain and preventing injury, as well as its limitations. This review provides an in-depth assessment of 2D video analysis studies for pitching, a direct comparison of 2D video versus 3D motion analysis, and a practical introduction to assessing pitching biomechanics using 2D video analysis. PMID:27618245

  9. Pediatric elbow injuries in athletes.

    PubMed

    Makhni, Eric C; Jegede, Kola A; Ahmad, Christopher S

    2014-09-01

    Elbow injuries in pediatric and adolescent population represent a spectrum of pathology that can range from medial tension injuries to posterior shear injuries. Elbow injuries in this population continue to rise in parallel with the increase in youth participation in sports both throughout the calendar year and across multiple sports. Many of these injuries are noncontact and are attributed to overuse. Evaluation and management of youth and adolescent athletic elbow injuries requires knowledge of developmental anatomy, injury pathophysiology, and established treatment algorithms. Furthermore, risk factors contributing to elbow injuries must be recognized, with education and recommendations for safe play continually advocated. This education--of parents, athletes, and coaches--is paramount in reducing the climbing incidence of elbow injuries in our youth athletes. PMID:25077752

  10. Nutrient Needs of Young Athletes.

    ERIC Educational Resources Information Center

    Willenberg, Barbara; Hemmelgarn, Melinda

    1991-01-01

    Explains the nutritional requirements of children and adolescents, and the physiological roles of the major nutrients. Details the nutrient needs of young athletes, including pre- and postgame meals and fluid replacement. Discusses eating disorders and obesity. Advocates a diet rich in complex carbohydrates. (BC)

  11. The Female Athlete Triad.

    PubMed

    Weiss Kelly, Amanda K; Hecht, Suzanne

    2016-08-01

    The number of girls participating in sports has increased significantly since the introduction of Title XI in 1972. As a result, more girls have been able to experience the social, educational, and health-related benefits of sports participation. However, there are risks associated with sports participation, including the female athlete triad. The triad was originally recognized as the interrelationship of amenorrhea, osteoporosis, and disordered eating, but our understanding has evolved to recognize that each of the components of the triad exists on a spectrum from optimal health to disease. The triad occurs when energy intake does not adequately compensate for exercise-related energy expenditure, leading to adverse effects on reproductive, bone, and cardiovascular health. Athletes can present with a single component or any combination of the components. The triad can have a more significant effect on the health of adolescent athletes than on adults because adolescence is a critical time for bone mass accumulation. This report outlines the current state of knowledge on the epidemiology, diagnosis, and treatment of the triad conditions. PMID:27432852

  12. The young female athlete.

    PubMed

    Hurvitz, Michal; Weiss, Ram

    2009-12-01

    Participation of adolescents and young women in strenuous sports activity may lead to various metabolic and psychological derangements of clinical relevance to the endocrinologist. The most common manifestations encountered in practice are primary and secondary amenorrhea, reduced bone mineral density and eating disorders. The occurrence of all three together has been named "the athletic triad". The underlying hormonal drivers that lead to some of these manifestations are the reduced leptin level as well as the persistent low grade stress response commonly observed in such females. "Exercise-related female reproductive dysfunction" (ERFRD), can possibly include short-term (infertility) and long-term (osteoporosis) consequences. Functional hypothalamic amenorrhea, a manifestation of ERFRD in adolescence, is an integrated response to the combination of excessive physical and emotional stress, exercise, and/or reduced food intake characterized by decreased endogenous GNRH secretion. The primary aim of treating these athletes should be the prevention of the development of any component of the triad as well as the whole complex by educating athletes, trainers, parents and health care professionals about proper nutrition and safe training. The long term prognosis is good. However, significant long term morbidity may affect these young women later in life. PMID:20118893

  13. Mechanical loading with or without weight-bearing activity: influence on bone strength index in elite female adolescent athletes engaged in water polo, gymnastics, and track-and-field.

    PubMed

    Greene, David A; Naughton, Geraldine A; Bradshaw, Elizabeth; Moresi, Mark; Ducher, Gaele

    2012-09-01

    Bone health is considered not to benefit from water-based sports because of their weight-supported nature, but available evidence primarily relies on DXA technology. Our purpose was to investigate musculoskeletal health in the upper and lower body in well-trained adolescent female athletes using pQCT and compare these athletes with less-active, age- and sex-matched peers. Bone mineral content, volumetric cortical and trabecular BMD, total and cortical area, and bone strength index were assessed at the distal and proximal tibia and radius in four groups of adolescent females (mean age, 14.9 years) including water polo players (n = 30), gymnasts (n = 25), track-and-field athletes (n = 34), and nonactive controls (n = 28). Water polo players did not show any benefit in bone strength index or muscle size in the lower leg when compared with controls. In contrast, gymnasts showed 60.1 % and 53.4 % greater bone strength index at the distal and proximal tibia, respectively, than nonactive females (p < 0.05). Similarly, track-and-field athletes displayed 33.9 % and 14.7 % greater bone strength index at the distal and proximal tibia, respectively, compared with controls (p < 0.05). In the upper body, water polo players had 31.9 % greater bone strength index at the distal radius, but not the radial shaft, and 15.2 % larger forearm muscle cross-sectional area than controls (p < 0.05). The greatest musculoskeletal benefits in the upper body were found in gymnasts. In conclusion, despite training at an elite level, female water polo players did not show any benefits in musculoskeletal health in the lower leg and only limited benefits in the upper body when compared with nonactive girls. PMID:22614913

  14. Athlete's foot

    MedlinePlus

    Tinea pedis; Fungal infection - feet; Tinea of the foot; Infection - fungal - feet; Ringworm - foot ... Athlete's foot is the most common type of tinea infection. The fungus or yeast thrives in warm, ...

  15. Athlete's foot

    MedlinePlus

    Tinea pedis; Fungal infection - feet; Tinea of the foot; Infection - fungal - feet; Ringworm - foot ... Athlete's foot occurs when a certain fungus or yeast grows on the skin of your feet. The same fungus ...

  16. On the Existence of Step-To-Step Breakpoint Transitions in Accelerated Sprinting

    PubMed Central

    McGhie, David; Danielsen, Jørgen; Sandbakk, Øyvind; Haugen, Thomas

    2016-01-01

    Accelerated running is characterised by a continuous change of kinematics from one step to the next. It has been argued that breakpoints in the step-to-step transitions may occur, and that these breakpoints are an essential characteristic of dynamics during accelerated running. We examined this notion by comparing a continuous exponential curve fit (indicating continuity, i.e., smooth transitions) with linear piecewise fitting (indicating breakpoint). We recorded the kinematics of 24 well trained sprinters during a 25 m sprint run with start from competition starting blocks. Kinematic data were collected for 24 anatomical landmarks in 3D, and the location of centre of mass (CoM) was calculated from this data set. The step-to-step development of seven variables (four related to CoM position, and ground contact time, aerial time and step length) were analysed by curve fitting. In most individual sprints (in total, 41 sprints were successfully recorded) no breakpoints were identified for the variables investigated. However, for the mean results (i.e., the mean curve for all athletes) breakpoints were identified for the development of vertical CoM position, angle of acceleration and distance between support surface and CoM. It must be noted that for these variables the exponential fit showed high correlations (r2>0.99). No relationship was found between the occurrences of breakpoints for different variables as investigated using odds ratios (Mantel-Haenszel Chi-square statistic). It is concluded that although breakpoints regularly appear during accelerated running, these are not the rule and thereby unlikely a fundamental characteristic, but more likely an expression of imperfection of performance. PMID:27467387

  17. Advancing hypoxic training in team sports: from intermittent hypoxic training to repeated sprint training in hypoxia

    PubMed Central

    Faiss, Raphaël; Girard, Olivier; Millet, Grégoire P

    2013-01-01

    Over the past two decades, intermittent hypoxic training (IHT), that is, a method where athletes live at or near sea level but train under hypoxic conditions, has gained unprecedented popularity. By adding the stress of hypoxia during ‘aerobic’ or ‘anaerobic’ interval training, it is believed that IHT would potentiate greater performance improvements compared to similar training at sea level. A thorough analysis of studies including IHT, however, leads to strikingly poor benefits for sea-level performance improvement, compared to the same training method performed in normoxia. Despite the positive molecular adaptations observed after various IHT modalities, the characteristics of optimal training stimulus in hypoxia are still unclear and their functional translation in terms of whole-body performance enhancement is minimal. To overcome some of the inherent limitations of IHT (lower training stimulus due to hypoxia), recent studies have successfully investigated a new training method based on the repetition of short (<30 s) ‘all-out’ sprints with incomplete recoveries in hypoxia, the so-called repeated sprint training in hypoxia (RSH). The aims of the present review are therefore threefold: first, to summarise the main mechanisms for interval training and repeated sprint training in normoxia. Second, to critically analyse the results of the studies involving high-intensity exercises performed in hypoxia for sea-level performance enhancement by differentiating IHT and RSH. Third, to discuss the potential mechanisms underpinning the effectiveness of those methods, and their inherent limitations, along with the new research avenues surrounding this topic. PMID:24282207

  18. Time interval moderates the relationship between psyching-up and actual sprint performance.

    PubMed

    Hammoudi-Nassib, Sarra; Chtara, Moktar; Nassib, Sabri; Briki, Walid; Hammoudi-Riahi, Sabra; Tod, David; Chamari, Karim

    2014-11-01

    This study attempted to test whether the strongest effect of psyching-up (PU) strategy on actual sprint performance can be observed when the strategy is used immediately (or almost) before performance compared with when there is a delay between PU and performance. To do so, 16 male sprinters (age, 20.6 ± 1.3 years; body mass, 77.5 ± 7.1 kg; height, 180.8 ± 5.6 cm) were enrolled in a counterbalanced experimental design in which participants were randomly assigned to 10 sessions (2 [Experimental Condition: imagery vs. distraction] × 5 [Time Intervals: no interval, 1 minute, 2 minutes, 3 minutes, and 5 minutes]). Before performing the experimental tasks, participants rated: (a) the Hooper index, (b) their degree of self-confidence, and (c) after the completion of the experimental test; they rated their perceived effort. Findings showed that the imagery significantly improved sprint performance. Specifically, the imagery enhanced performance on the phase of acceleration (0-10 m) and on the overall sprint (0-30 m) when used immediately before performance and at 1- and 2-minute intervals but not for 3- and 5-minute intervals. These findings support the hypothesis that the potential effect of the PU strategy on performance vanishes over time. The pre-experimental task Hooper and self-efficacy indexes did not change across the 10 experimental sessions, reinforcing the view that the observed performance changes were directly caused by the experimental manipulation and not through any altered status of the athletes (self-efficacy, fatigue/recovery, and stress). The potential mechanisms underlying such a process and practical applications are discussed. PMID:25029002

  19. On the Existence of Step-To-Step Breakpoint Transitions in Accelerated Sprinting.

    PubMed

    Ettema, Gertjan; McGhie, David; Danielsen, Jørgen; Sandbakk, Øyvind; Haugen, Thomas

    2016-01-01

    Accelerated running is characterised by a continuous change of kinematics from one step to the next. It has been argued that breakpoints in the step-to-step transitions may occur, and that these breakpoints are an essential characteristic of dynamics during accelerated running. We examined this notion by comparing a continuous exponential curve fit (indicating continuity, i.e., smooth transitions) with linear piecewise fitting (indicating breakpoint). We recorded the kinematics of 24 well trained sprinters during a 25 m sprint run with start from competition starting blocks. Kinematic data were collected for 24 anatomical landmarks in 3D, and the location of centre of mass (CoM) was calculated from this data set. The step-to-step development of seven variables (four related to CoM position, and ground contact time, aerial time and step length) were analysed by curve fitting. In most individual sprints (in total, 41 sprints were successfully recorded) no breakpoints were identified for the variables investigated. However, for the mean results (i.e., the mean curve for all athletes) breakpoints were identified for the development of vertical CoM position, angle of acceleration and distance between support surface and CoM. It must be noted that for these variables the exponential fit showed high correlations (r2>0.99). No relationship was found between the occurrences of breakpoints for different variables as investigated using odds ratios (Mantel-Haenszel Chi-square statistic). It is concluded that although breakpoints regularly appear during accelerated running, these are not the rule and thereby unlikely a fundamental characteristic, but more likely an expression of imperfection of performance. PMID:27467387

  20. What is the Safest Sprint Starting Position for American Football Players?

    PubMed Central

    Bonnechere, Bruno; Beyer, Benoit; Rooze, Marcel; Sint, Jan Serge Van

    2014-01-01

    The main objective of this study was to perform a biomechanical analysis of three different sprint start patterns to determine the safest position in term of neck injury and Sport-Related Concussion (SRC). The second objective was to collect data on the learning process effect between football players and non-players. Three different sprint initial positions adopted by football players were studied (i.e., 4-, 3- and 2-point positions). Twenty five young healthy males, including 12 football players, participated to this study. A stereophotogrammetric system (i.e., Vicon) was used to record motion patterns and body segments positions. Various measurements related to head and trunk orientation, and player field-of-view were obtained (e.g., head height, trunk bending, time to reach upright position, head speed (vertical direction) and body speed (horizontal direction)). Learning process was found to have no influence on studied parameters. Head redress is also delayed when adopting a 4-point position leading to a reduce field-of-view during the start and increasing therefore the probability of collision. Concerning the three different positions, the 4-point position seems to be the more dangerous because leading to higher kinetic energy than the 2- and 3-point start positions. This study proposes a first biomechanical approach to understand risk/benefit balance for athletes for those three different start positions. Results suggested that the 4-point position is the most risky for football players. Key points Motion analysis and biomechanical analysis of the initial start position of the sprint could be used to increase the safety of the football players. Analysis of kinematic and trajectory of the head and the time to reach the upright position could be used to determine whether or not a player can return to play after concussion. A balance needs to be found between player’s safety (2-point start) and speed (4-point start). PMID:24790500

  1. Effects of Warm-Up Stretching Exercises on Sprint Performance

    ERIC Educational Resources Information Center

    Makaruk, Hubert; Makaruk, Beata; Kedra, Stanislaw

    2008-01-01

    Study aim: To assess direct effects of warm-up consisting of static and dynamic stretching exercises on sprint results attained by students differing in sprint performance. Material and methods: A group of 24 male and 19 female physical education students, including 12 and 9 sprinters, respectively. They performed warm-ups consisting of dynamic…

  2. Determination of rotational kinematics of the lower leg during sprint running using accelerometers

    NASA Astrophysics Data System (ADS)

    Channells, Justin; Purcell, Brendan; Barrett, Rod; James, Daniel

    2006-01-01

    Motion analysis systems measure and calculate the position of markers fixed to the body but generally restrict measurement to the laboratory environment. In contrast, inertial measurement devices are small, lightweight and self-contained and data collection is not restricted to a laboratory. Most research using inertial measurement in human locomotion studies has focused on walking. This paper describes a wireless accelerometer-based method for measuring shank angular velocity during sprint running. The system consists of body-mounted electronics with a wireless connection to a PC programmed with the necessary equations to interpret the acceleration data. The hardware incorporates two sets of accelerometers measuring acceleration in each of the three axes. The two 3D accelerometers are fixed to a frame so that their axes are aligned and they are separated by a prescribed distance. By calculating the difference in acceleration between the two 3D sensors, the gravitational component and linear acceleration components are cancelled leaving the rotational acceleration components. An onboard microcontroller digitises the accelerometer signals and the data is transmitted wirelessly to a PC to calculate the angular velocity with minimal latency. Tests were conducted on several subjects running at a constant velocity for several different speeds. The angular rate output from the accelerometer-based system was compared to data obtained from an optical motion analysis system. Validation test results indicate an accurate result was obtained. The design's suitability for acquiring data during elite athlete sprint training is examined and other applications considered. Error reduction strategies will also be discussed.

  3. Considerations of force plate transitions on centre of pressure calculation for maximal velocity sprint running.

    PubMed

    Exell, Timothy A; Gittoes, Marianne J R; Irwin, Gareth; Kerwin, David G

    2012-11-01

    The aims of this study were to evaluate the accuracy of centre of pressure (COP) data obtained during transition of load across the boundary between two force plates, and secondly to examine the effect of such COP data on joint kinetics during sprint running performances. COP data were collected from two piezoelectric force plates as a trolley wheel was rolled across the boundary between the plates. Position data for the trolley were collected using an opto-electronic motion analysis system for comparison with COP data. Mean COP errors during transition across the plate boundary were 0.003 +/- 0.002 m relative to a control point. Kinematic and kinetic data were also collected from eight athletes during sprint running trials to demonstrate the sensitivity of the inverse dynamics analysis to COP error for the ground contact phase of the dynamic movement trials. Kinetic sensitivity to the COP error was assessed during the entire stance phase for the ankle, knee, and hip joints and was less than 5% and 3% for joint moment and power data, respectively. Based on the small COP error during transition across plate boundaries, it is recommended that foot contacts overlapping two force plates may be included in inverse dynamics analyses. PMID:23259242

  4. Athletic Activity and Hormone Concentrations in High School Female Athletes

    PubMed Central

    Wojtys, Edward M.; Jannausch, Mary L.; Kreinbrink, Jennifer L.; Harlow, Siobán D.; Sowers, MaryFran R.

    2015-01-01

    Context: Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical. Objective: To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean–body-mass to fat–body-mass ratio with accompanying hormonal changes. Design: Cohort study. Settings: Laboratory and participants' homes. Patients or Other Participants: A total of 106 adolescent girls, ages 14–18 years, who had experienced at least 3 menstrual cycles in their lifetime. Main Outcome Measure(s): Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period. Results: Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant. Conclusions: A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the

  5. Tactical behaviour of winning athletes in major championship 1500-m and 5000-m track finals.

    PubMed

    Aragón, Sonia; Lapresa, Daniel; Arana, Javier; Anguera, M Teresa; Garzón, Belén

    2016-01-01

    This article analyses the tactics employed by middle-distance (1500-m) and long-distance (5000-m) runners from an observational methodology perspective. The subject of investigation has received little attention from specialists in the field of athletics, with most research focusing on physiological studies of athlete performance. Using an ad hoc observation tool and a database containing systematically recorded data we detected time patterns (T-patterns) within the data recorded using the Theme software program (version 5.0), and analysed the tactics employed by winners of the men's 1500-m and 5000-m finals of the World Championships in Athletics [Edmonton 2001, Paris 2003, Helsinki 2005 (1500-m final only), Osaka 2007 (1500-m final only), Berlin 2009 and Daegu 2011], the European Athletics Championships (Munich 2002, Göteborg 2006, and Barcelona 2010) and the Olympic Games (Sydney 2000, Athens 2004, Beijing 2008 and London 2012). T-pattern detection and investigation of the relationship between category systems corresponding to the criteria comprising the observation tool revealed both similarities (starting lane and lane used during race, runner's position during race and sprint zone and lane) and differences (variations in pace, zones in which changes of pace occur, sprint initiation zone and winner's position at the start of the sprint) between the two disciplines. PMID:25665767

  6. Liability, Athletic Equipment, and the Athletic Trainer.

    ERIC Educational Resources Information Center

    Black, Richard

    Standards of conduct, roles, and responsibilities expected of athletic trainers should be developed and disseminated. These guidelines could be used in court to show that the athletic trainer was following basic standards if he should be charged with liability. A review of liability cases involving athletic injuries received while athletes were…

  7. Athletics, Athletic Leadership, and Academic Achievement

    ERIC Educational Resources Information Center

    Yeung, Ryan

    2015-01-01

    This study examines the relationship between athletics, athletic leadership, and academic achievement. This is likely to be a tricky issue as athletes and athletic leaders are not likely to be a random group of students. To address this issue I control for school fixed effects and instrument the endogenous variables with height. I find that…

  8. The acute effects of green tea and carbohydrate coingestion on systemic inflammation and oxidative stress during sprint cycling.

    PubMed

    Suzuki, Katsuhiko; Takahashi, Masaki; Li, Chia-Yang; Lin, Shiuan-Pey; Tomari, Miki; Shing, Cecilia M; Fang, Shih-Hua

    2015-10-01

    Green tea (Camellia sinensis) has anti-oxidative and anti-inflammatory effects, which may be beneficial to athletes performing high-intensity exercise. This study investigated the effects of carbohydrate and green tea coingestion on sprint cycling performance and associated oxidative stress and immunoendocrine responses to exercise. In a crossover design, 9 well-trained male cyclists completed 3 sets of 8 repetitions of 100-m uphill sprint cycling while ingesting green tea and carbohydrate (TEA) (22 mg/kg body mass catechins, 6 mg/kg body mass caffeine, 230 mg/kg glucose, and 110 mg/kg fructose) or carbohydrate only (CHO) (230 mg/kg body mass glucose and 110 mg/kg body mass fructose) during each 10-min recovery period between sets. Blood samples were collected before exercise, 10 min after exercise, and 14 h after exercise. There was no effect of acute TEA ingestion on cycling sprint performance (p = 0.29), although TEA maintained postexercise testosterone and lymphocyte concentrations, which decreased significantly in the CHO group (p < 0.001). While there was a trend for lower postexercise neutrophil count with TEA (p = 0.05), there were no significant differences between TEA and CHO for circulating cytokines (p > 0.20), markers of oxidative stress and antioxidant capacity (p > 0.17), adiponectin concentration (p = 0.60), or muscle damage markers (p > 0.64). While acute green tea ingestion prevents the postexercise decrease in testosterone and lymphocytes, it does not appear to benefit cycling sprint performance or reduce markers of oxidation and inflammation when compared with carbohydrate alone. PMID:26319564

  9. Are "classical" tests of repeated-sprint ability in football externally valid? A new approach to determine in-game sprinting behaviour in elite football players.

    PubMed

    Schimpchen, Jan; Skorski, Sabrina; Nopp, Stephan; Meyer, Tim

    2016-01-01

    The aim of this study was to investigate the occurrence of repeated sprinting bouts in elite football. Furthermore, the construct validity of current tests assessing repeated-sprint ability (RSA) was analysed using information of sprinting sequences as they actually occurred during match-play. Sprinting behaviour in official competition was analysed for 19 games of the German national team between August 2012 and June 2014. A sprinting threshold was individually calculated based on the peak velocity reached during in-game sprinting. Players performed 17.2 ± 3.9 sprints per game and during the entire 19 games a total of 35 bouts of repeated sprinting (a minimum of three consecutive sprints with a recovery duration <30 s separating efforts). This averages one bout of repeated sprinting per player every 463 min. No general decrement in maximal sprinting speed was observed during bouts with up to five consecutive sprints. Results of the present study question the importance of RSA as it is classically defined. They indicate that shorter accelerations are more important in game-specific situations which do not reach speeds necessary to qualify them as sprints. The construct validity of classic tests of RSA in football is not supported by these observations. PMID:26580089

  10. Application of a body-weight-supporting kite for sprint running.

    PubMed

    Kratky, Sascha; Müller, Erich

    2013-11-01

    Improvements in sprint performance at the top level require adaptations concerning force application because ground contact time diminishes with increasing velocity. Applied training methods and devices must provoke appropriate stimuli. A knowledge about positive and negative effects of these stimuli is vital for coaches. The purpose of this study was to determine the angle of attack and lifting and retarding forces of a novel sprint training device that supports the athlete's body weight (BW), thereby decreasing ground contact time during sprints. Three different kite sizes (1.10, 1.75, 2.25 m) were investigated. A bicycle was used to accelerate the National Aeronautics and Space Administration (NASA) parawings (NPW-120, NPW-150, and NPW-170) on an indoor track to acquire data at velocities between 6.5 and 10.5 m · s. During a 5-m interval of constant speed, the resultant force of the kite was recorded on a portable computer by a load cell. The angle of attack was determined by a high-speed camera, and the mean velocity in the 5-m sector was measured by a laser gauge. Lifting and retarding forces were derived from the resultant force and angle of attack. Quadratic regression equations for lifting and retarding forces, depending on the velocity, were calculated for all 3 NPWs. A clear difference (p < 0.001) depending on the kite size was revealed for lifting and retarding forces. These forces also indicated high correlation coefficients related to velocity (r > 0.98; p < 0.001), whereas the angle of attack remained almost constant across the entire velocity range in all NPWs, yielding a lift-to-drag ratio of 2.35. Because of the kite's small retarding forces, we recommend the application of the NPW during the high-speed phase of sprinting with lifting force probably counteracting adverse effects. By adding a towing system, the retarding force can be fine tuned, erased, or turned into overspeed assistance, thereby emphasizing BW support. PMID:23442285

  11. Hazing of suburban middle school and high school athletes.

    PubMed

    Gershel, Jeffrey C; Katz-Sidlow, Rachel J; Small, Eric; Zandieh, Stephanie

    2003-05-01

    Little is known about the prevalence of hazing behaviors among adolescent athletes. Our survey of 1105 6th-12th grade athletes found that 17.4% had been subjected to practices that qualify as hazing. Many of these teenagers do not comprehend the abusive and potentially dangerous nature of hazing. PMID:12729981

  12. Patellofemoral pain syndrome in Iranian female athletes.

    PubMed

    Nejati, Parisa; Forogh, Bijan; Moeineddin, Reza; Baradaran, Hamid Reza; Nejati, Mina

    2011-01-01

    Patellofemoral pain syndrome (PFPS) is the most common overuse syndrome in athletes. It is one of the causes of anterior knee pain in athletic population who come to the sports medicine clinic. Patellofemoral pain is more common among female athletes especially adolescents and young adults. Symptoms include: persistent pain behind the patella or peripatella. Pain increases on ascending and descending stairs and squatting and prolonged sitting. The aim of this study was to evaluate the prevalence of PFPS in Iranian female athletes. 418 female athletes aged 15-35 years were examined in five sports: Soccer (190), volleyball (103), running (42), fencing (45) and rock climbing (38). The athletes who had non- traumatic onset anterior knee pain of at least 3 months that increased in descending and ascending stairs and squatting, had no other causes of anterior knee pain such as ligament instability, bursitis, meniscal injury, tendonitis and arthritis and no history of knee surgery during the one past year were diagnosed as PFPS. 26/190 (13.68 %) soccer players, 21/103(20.38 %) volleyball players, 7/42 (16.66 %) runners, 6/45(13.33 %) fencers and 10/38 (26.31%) rock climbers had patellofemoral pain. Among the 418 female athletes who were evaluated 70 had PFPS. Rock climbers were the most common athletes with PFPS followed by volleyball players and runners. PMID:21681705

  13. Low back pain in a competitive cricket athlete.

    PubMed

    Merlino, Justin; Perisa, Jack

    2012-02-01

    Physical therapists treating adolescent and young adult athletes with low back pain complaints should have a high level of clinical suspicion of the possibility for spondylolysis, spondylolisthesis, or developing stress reactions of the pars interarticularis. This case outlines the use of conventional radiography, computerized tomography, and Single photon emission computed tomography (SPECT) in the differential diagnosis for an adolescent cricket athlete with low back pain. PMID:22319683

  14. Joint Cooling does not Hinder Athletic Performance during High-intensity Intermittent Exercise.

    PubMed

    Kim, H; Lee, D; Choi, H-M; Park, J

    2016-07-01

    We examined the effects of ankle and knee joint cooling on 20-m sprint times and maximal vertical jump heights during high-intensity intermittent exercise. 21 healthy collegiate male basketball (n=14) and handball players (n=7) underwent 3 experimental sessions. Each session consisted of four 15-min quarters of high-intensity intermittent exercises including various intensities of 20-m shuttle running and jumping. A 20-min bilateral joint cooling (ankle, knee, or control-no cooling: in a counterbalanced order) was applied before quarters 1 and 3. After joint cooling, no warm-up activity other than the exercise protocol was given. The 20-m sprint times and maximal vertical jump heights in each experimental session were recorded at baseline (prior to quarter-1) and during each quarter. To test joint cooling effects over time, we performed 3×5 mixed model ANOVAs. Neither ankle nor knee joint cooling changed 20-m sprint times (F8,280=1.45; p=0.18) or maximal vertical jump heights (F8,280=0.76; p=0.64). However, a trend was observed in which joint cooling immediately decreased (quarters 1 and 3) but active warm-up for approximately 20 min improved 20-min sprint times (quarters 2 and 4). Our study suggests that athletic performance such as sprinting and jumping are not altered by joint cooling applied prior to or during high-intensity intermittent exercise. PMID:27119166

  15. Longitudinal Study Evaluating Postural Balance of Young Athletes.

    PubMed

    Steinberg, Nili; Nemet, Dan; Pantanowitz, Michal; Zeev, Aviva; Hallumi, Monder; Sindiani, Mahmood; Meckel, Yoav; Eliakim, Alon

    2016-02-01

    Repeated anaerobic conditions during athletic performance may cause general and local fatigue that result in postural balance deficit. Evidence suggests that improved postural balance during athletic training may decrease the risk for fallings and traumatic injuries among athletes. Twenty athletes (12 girls, 8 boys) and 20 controls (12 girls, 8 boys) ages 10-15 years participated in the current study. All athletes were active in an 8-month physical activity program, 3 times per week for 90 min., specific to basketball, soccer, or athletic training. The control children participated in physical education at school only, with no involvement in organized extracurricular sports. All participants were evaluated for postural balance in three assessments over one year (at 4-mo intervals); the Interactive Balance System machine (Tetrax device) was used to assess balance at three test times (pre-, post-, and 10 min) after a session of a repeated sprint anaerobic test, consisting of 12 × 20 m run starting every 20 sec. The athletes had better postural balance than controls. There were different group patterns of change over the sessions; a significant interaction of session and group indicated that postural balance of the groups differed. The contribution of low sway frequencies (F1) and high sway frequencies (F6) differed between the controls and the athletes group. Results suggested that although athletes had better postural balance, improvement should be encouraged during training over the sessions and seasons, with special awareness of the balance deficit that occurs immediately after anaerobic stress and at the end of the season, to decrease the risk of injuries. PMID:27420320

  16. Perceived parenting styles differ between genders but not between elite athletes and controls.

    PubMed

    Brand, Serge; Gerber, Markus; Beck, Johannes; Kalak, Nadeem; Hatzinger, Martin; Pühse, Uwe; Holsboer-Trachsler, Edith

    2011-01-01

    For adolescent elite athletes, parental financial and emotional support is crucial. However, parents of elite athletes may be critical and demanding. Moreover, there is evidence that girls report more favorable perceived parenting styles compared with boys. The aim of the present study was to investigate perceived parenting styles among female and male adolescent elite athletes and controls. We sampled 258 adolescent elite athletes (139 females, 119 males) and 176 controls (139 females, 37 males). Participants completed a questionnaire to assess perceived parenting styles (support, commendation, reproach, restriction, inconsistency). Results showed that parenting styles did not differ between athletes and controls, except for restriction, for which athletes reported lower levels. Female adolescents had higher scores for positive and lower scores for negative perceived parenting styles. PMID:24600271

  17. The Anemias of Athletes.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1986-01-01

    Diagnosing anemia in athletes is complicated because athletes normally have a pseudoanemia that needs no treatment. Athletes, however, can develop anemia from iron deficiency or footstrike hemolysis, which require diagnosis and treatment. (Author/MT)

  18. Giving students the run of sprinting models

    NASA Astrophysics Data System (ADS)

    Heck, André; Ellermeijer, Ton

    2009-11-01

    A biomechanical study of sprinting is an interesting task for students who have a background in mechanics and calculus. These students can work with real data and do practical investigations similar to the way sports scientists do research. Student research activities are viable when the students are familiar with tools to collect and work with data from sensors and video recordings and with modeling tools for comparing simulation and experimental results. This article describes a multipurpose system, named COACH, that offers a versatile integrated set of tools for learning, doing, and teaching mathematics and science in a computer-based inquiry approach. Automated tracking of reference points and correction of perspective distortion in videos, state-of-the-art algorithms for data smoothing and numerical differentiation, and graphical system dynamics based modeling are some of the built-in techniques that are suitable for motion analysis. Their implementation and their application in student activities involving models of running are discussed.

  19. Innovative camera system developed for Sprint vehicle

    SciTech Connect

    Not Available

    1985-04-01

    A new inspection system for the Sprint 101 ROV eliminates parallax errors because all three camera modules use a single lens for viewing. Parallax is the apparent displacement of an object when it is viewed from two points not in the same line of sight. The central camera is a Pentax 35-mm single lens reflex with a 28-mm lens. It comes with 250-shot film cassettes, an automatic film wind-on, and a data chamber display. An optical transfer assembly on the stills camera viewfinder transmits the image to one of the two video camera modules. The video picture transmitted to the surface is exactly the same as the stills photo. The surface operator can adjust the focus by viewing the video display.

  20. Acute Response of Well-Trained Sprinters to a 100-m Race: Higher Sprinting Velocity Achieved With Increased Step Rate Compared With Speed Training.

    PubMed

    Otsuka, Mitsuo; Kawahara, Taisuke; Isaka, Tadao

    2016-03-01

    This study aimed to clarify the contribution of differences in step length and step rate to sprinting velocity in an athletic race compared with speed training. Nineteen well-trained male and female sprinters volunteered to participate in this study. Sprinting motions were recorded for each sprinter during both 100-m races and speed training (60-, 80-, and 100-m dash from a block start) for 14 days before the race. Repeated-measures analysis of covariance was used to compare the step characteristics and sprinting velocity between race and speed training, adjusted for covariates including race-training differences in the coefficients of restitution of the all-weather track, wind speed, air temperature, and sex. The average sprinting velocity to the 50-m mark was significantly greater in the race than in speed training (8.26 ± 0.22 m·s vs. 8.00 ± 0.70 m·s, p < 0.01). Although no significant difference was seen in the average step length to the 50-m mark between the race and speed training (1.81 ± 0.09 m vs. 1.80 ± 0.09 m, p = 0.065), the average step rate was significantly greater in the race than in speed training (4.56 ± 0.17 Hz vs. 4.46 ± 0.13 Hz, p < 0.01). These findings suggest that sprinters achieve higher sprinting velocity and can run with higher exercise intensity and more rapid motion during a race than during speed training, even if speed training was performed at perceived high intensity. PMID:26907837

  1. Overview (northeast to southwest) of remote sprint launch site #4. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Overview (northeast to southwest) of remote sprint launch site #4. In center is limited area sentry station, just behind it can be seen the exhaust and intake shafts for the remote launch operations building, and to the far right is the exclusion area sentry station - Stanley R. Mickelsen Safeguard Complex, Remote Sprint Launch Site No. 4, North of State Highway 17, approximately 9 miles Northwest of Adams, ND, Nekoma, Cavalier County, ND

  2. Evaluation of Low Back Pain in Athletes

    PubMed Central

    Daniels, James M.; Pontius, Gina; El-Amin, Saadiq; Gabriel, Keith

    2011-01-01

    Context: Low back pain is a common complaint in athletes. Athletes differ from the general population physiologically, making it unclear if the evaluation of low back pain should differ between these 2 groups. Evidence Acquisition: A literature search (PubMed, Ovid) was performed for the years 1995 through 2010. Keywords used were lumbar back pain, athletes, and adolescence. Results: Athletes with low back pain represent a very diverse group. The evaluation depends on the athlete’s age and the presence of “red flags.” The most common causes of low back pain in the preadolescent population are infection, tumor, and trauma. In the adolescent population, trauma spondylolysis/spondylolisthesis and hyperlordosis are commonly seen. Leading causes in the adult population are mechanics and osteoarthritis. The elderly frequently present with osteoarthritis, spinal stenosis, and internal medical etiologies. Conclusion: Athletes with back pain should have a diagnostic workup guided by their age, history, and physical examination. Although this work up is similar in nonathletes, the demands of the athlete must be taken into account in a treatment plan. PMID:23016026

  3. Effect of different warm-up procedures on subsequent swim and overall sprint distance triathlon performance.

    PubMed

    Binnie, Martyn J; Landers, Grant; Peeling, Peter

    2012-09-01

    This study investigated the effect of 3 warm-up procedures on subsequent swimming and overall triathlon performance. Seven moderately trained, amateur triathletes completed 4 separate testing sessions comprising 1 swimming time trial (STT) and 3 sprint distance triathlons (SDT). Before each SDT, the athletes completed 1 of three 10-minute warm-up protocols including (a) a swim-only warm-up (SWU), (b) a run-swim warm-up (RSWU), and (c) a control trial of no warm-up (NWU). Each subsequent SDT included a 750-m swim, a 500-kJ (∼20 km) ergometer cycle and a 5-km treadmill run, which the athletes performed at their perceived race intensity. Blood lactate, ratings of perceived exertion, core temperature, and heart rate were recorded over the course of each SDT, along with the measurement of swim speed, swim stroke rate, and swim stroke length. There were no significant differences in individual discipline split times or overall triathlon times between the NWU, SWU, and RSWU trials (p > 0.05). Furthermore, no difference existed between trials for any of the swimming variables measured (p > 0.05) nor did they significantly differ from the preliminary STT (p > 0.05). The findings of this study suggest that warming up before an SDT provides no additional benefit to subsequent swimming or overall triathlon performance. PMID:22067241

  4. Nutritional concerns during adolescence.

    PubMed

    Marino, D D; King, J C

    1980-02-01

    Adolescent food habits often run counter to the special nutritional needs of this age group. Suggestions for nutrient supplements are offered, with particular emphasis on fulfilling the unique needs of the obese, athletic, or pregnant teenager. PMID:6445537

  5. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players

    PubMed Central

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-01-01

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 – 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed. PMID:26834881

  6. Hand Grip Strength Vs. Sprint Effectiveness in Amputee Soccer Players.

    PubMed

    Wieczorek, Marta; Wiliński, Wojciech; Struzik, Artur; Rokita, Andrzej

    2015-11-22

    Amputee soccer is one of the types of soccer designed for the disabled, especially those who have undergone amputations, as well as those with extremity dysfunction. The objective of the study was to find the relationship between hand grip strength and sprint time in amputee soccer players. Thirteen field amputee soccer players participated in the study. A SAEHAN hydraulic hand dynamometer manufactured by Jamar was used for hand grip strength measurements. The sprint running test was conducted over a distance of 30 m. The Fusion Smart Speed System was employed for running time measurements. No statistically significant relationships were found between hand grip strength of the left or right hand, and sprint times over 1, 5, 10, 15, 20, 25 and 30 m. Analysis of the running velocity curve of the subjects showed an interesting profile characterized by a 15 meter-long acceleration phase and a significant velocity increase over a distance of 20 - 25 m. The study suggests that there is no relationship between hand grip strength and sprint effectiveness in amputee soccer players. The specificity of locomotion with the use of elbow crutches among elite Polish amputee soccer players probably accounts for the profile of the sprint velocity curve. Extension of the acceleration phase in the sprint run and a velocity increase in the subsequent part of the run were observed. PMID:26834881

  7. Athlete and Non-Athlete Adjustment to College

    ERIC Educational Resources Information Center

    Drum, Jennifer; Ladda, Shawn; Geary, Colette; Fitzpatrick, Corine

    2014-01-01

    This study examined college adjustment between athletes and non-athletes at Manhattan College, a medium-sized college participating in NCAA Division I athletics located in the Bronx, New York. Groups included a total of fifty-two athletes, fifty-six non-athletes, twenty-five female athletes, twenty-seven male athletes, twenty-six female…

  8. The Relationship between Coach Leadership, the Coach-Athlete Relationship, Team Success, and the Positive Developmental Experiences of Adolescent Soccer Players

    ERIC Educational Resources Information Center

    Vella, Stewart A.; Oades, Lindsay G.; Crowe, Trevor P.

    2013-01-01

    Background: The goals of participation youth sports are primarily concerned with the facilitation of positive youth development as opposed to outright success. Consequently, there are strong theoretical and empirical links between sports coaching and athlete development. Transformational leadership behaviours, in particular, have been…

  9. Athletics and the Law.

    ERIC Educational Resources Information Center

    Appenzeller, Herb

    This book answers questions concerning athletics and the law. The chapters include trends in litigation, disruptive behavior, the changing attitude of the court toward married athletes, training rules, and good conduct codes. They include the problem of athletic travel, the changing role of state athletic associations with their diverse rules,…

  10. Collegiate Athletics Highlights.

    ERIC Educational Resources Information Center

    St. John, Eric

    1999-01-01

    Highlights 15 trends/events in black college athletics, including championship coaches, Black Coaches Association, eligibility issues, disclosure of athlete graduation rates, athletics resource allocation, early adoption of professional athlete status, success of the Women's National Basketball Association, lack of black access to certain sports,…

  11. A rise in peak performance age in female athletes.

    PubMed

    Elmenshawy, Ahmed R; Machin, Daniel R; Tanaka, Hirofumi

    2015-06-01

    It was reported in 1980s that ages at which peak performance was observed had remained remarkably stable in the past century, although absolute levels of athletic performance increased dramatically for the same time span. The emergence of older (masters) athletes in the past few decades has changed the demographics and age-spectrum of Olympic athletes. The primary aim of the present study was to determine whether the ages at which peak performance was observed had increased in the recent decades. The data spanning 114 years from the first Olympics (1898) to the most recent Olympics (2014) were collected using the publically available data. In the present study, ages at which Olympic medals (gold, silver, and bronze) were won were used as the indicators of peak performance age. Track and field, swimming, rowing, and ice skating events were analyzed. In men, peak performance age did not change significantly in most of the sporting events (except in 100 m sprint running). In contrast, peak performance ages in women have increased significantly since 1980s and consistently in all the athletic events examined. Interestingly, as women's peak performance age increased, they became similar to men's peak ages in many events. In the last 20-30 years, ages at which peak athletic performance is observed have increased in women but not in men. PMID:26022534

  12. Jocks, Gender, Binge Drinking, and Adolescent Violence

    ERIC Educational Resources Information Center

    Miller, Kathleen E.; Melnick, Merrill J.; Farrell, Michael P.; Sabo, Donald F.; Barnes, Grace M.

    2006-01-01

    Previous research has suggested a link between athletic involvement and elevated levels of adolescent violence outside the sport context. The present study expanded on this literature by positing differences in the sport-violence relationship across dimensions of athletic involvement (athletic participation vs. jock identity), type of violence…

  13. A Combination of Amino Acids and Caffeine Enhances Sprint Running Capacity in a Hot, Hypoxic Environment.

    PubMed

    Eaton, Tom R; Potter, Aaron; Billaut, François; Panchuk, Derek; Pyne, David B; Gore, Christopher J; Chen, Ting-Ting; McQuade, Leon; Stepto, Nigel K

    2016-02-01

    Heat and hypoxia exacerbate central nervous system (CNS) fatigue. We therefore investigated whether essential amino acid (EAA) and caffeine ingestion attenuates CNS fatigue in a simulated team sport-specific running protocol in a hot, hypoxic environment. Subelite male team sport athletes (n = 8) performed a repeat sprint running protocol on a nonmotorized treadmill in an extreme environment on 4 separate occasions. Participants ingested one of four supplements: a double placebo, 3 mg.kg-1 body mass of caffeine + placebo, 2 x 7 g EAA (Musashi Create)+placebo, or caffeine + EAA before each exercise session using a randomized, double-blind crossover design. Electromyography (EMG) activity and quadriceps evoked responses to magnetic stimulation were assessed from the dominant leg at preexercise, halftime, and postexercise. Central activation ratio (CAR) was used to quantify completeness of quadriceps activation. Oxygenation of the prefrontal cortex was measured via near-infrared spectroscopy. Mean sprint work was higher (M = 174 J, 95% CI [23, 324], p < .05, d = 0.30; effect size, likely beneficial) in the caffeine + EAA condition versus EAAs alone. The decline in EMG activity was less (M = 13%, 95% CI [0, 26]; p < .01, d = 0.58, likely beneficial) in caffeine + EAA versus EAA alone. Similarly, the pre- to postexercise decrement in CAR was significantly less (M = -2.7%, 95% CI [0.4, 5.4]; p < .05, d = 0.50, likely beneficial) when caffeine + EAA were ingested compared with placebo. Cerebral oxygenation was lower (M = -5.6%, 95% CI [1.0, 10.1]; p < .01, d = 0.60, very likely beneficial) in the caffeine + EAA condition compared with LNAA alone. Co-ingestion of caffeine and EAA appears to maintain muscle activation and central drive, with a small improvement in running performance. PMID:26248498

  14. Muscle Oxygen Changes following Sprint Interval Cycling Training in Elite Field Hockey Players

    PubMed Central

    Jones, Ben; Hamilton, David K.; Cooper, Chris E.

    2015-01-01

    This study examined the effects of Sprint Interval Cycling (SIT) on muscle oxygenation kinetics and performance during the 30-15 intermittent fitness test (IFT). Twenty-five women hockey players of Olympic standard were randomly selected into an experimental group (EXP) and a control group (CON). The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program. To explore the potential training-induced change, EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training. During these tests near-infrared spectroscopy (NIRS) measured parameters; oxyhaemoglobin + oxymyoglobin (HbO2+ MbO2), tissue deoxyhaemoglobin + deoxymyoglobin (HHb+HMb), total tissue haemoglobin (tHb) and tissue oxygenation (TSI %) were taken. In the EXP group (5.34±0.14 to 5.50±0.14m.s-1) but not the CON group (pre = 5.37±0.27 to 5.39±0.30m.s-1) significant changes were seen in the 30-15IFT performance. EXP group also displayed significant post-training increases during the sprint cycling: ΔTSI (−7.59±0.91 to −12.16±2.70%); ΔHHb+HMb (35.68±6.67 to 69.44±26.48μM.cm); and ΔHbO2+ MbO2 (−74.29±13.82 to −109.36±22.61μM.cm). No significant differences were seen in ΔtHb (−45.81±15.23 to −42.93±16.24). NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes. PMID:25807517

  15. Responses of sex steroid hormones to different intensities of exercise in endurance athletes.

    PubMed

    Sato, Koji; Iemitsu, Motoyuki; Katayama, Keisho; Ishida, Koji; Kanao, Yoji; Saito, Mitsuru

    2016-01-01

    Previous studies have shown that acute exercise elevates sex steroid hormone concentrations in rodents and that sprint exercise increases circulating testosterone in healthy young men. However, the effect of different exercise intensities on sex steroid hormone responses at different levels of physical fitness is still unclear. In this study, we compared circulating sex steroid hormone responses at different exercise intensities in athletes and non-athletes. Eight male endurance athletes and 11 non-athletes performed two 15 min sessions of submaximal exercise at 40 and 70% peak oxygen uptake (V̇(O2peak)), respectively, and exercised at 90% V̇(O2peak) until exhaustion. Venous blood samples were collected during the last minute of each submaximal exercise session and immediately after exhaustion. Acute exercise at 40, 70 and 90% V̇(O2peak) induced significant increases in serum dehydroepiandrosterone (DHEA) and free testosterone concentrations in non-athletes. On the contrary, only 90% V̇O2 peak exercise led to an increase in serum DHEA and free testosterone concentrations in athletes. Serum 5α-dihydrotestosterone concentrations increased with 90% V̇(O2peak) exercise in both athletes and non-athletes. Additionally, serum estradiol concentrations were significantly increased at moderate and high exercise intensities in both athletes and non-athletes. These results indicate that in endurance athletes, serum sex steroid hormone concentrations, especially serum DHEA and 5α-dihydrotestosterone concentrations, increased only with high-intensity exercise, suggesting that different responses of sex steroid hormone secretion are induced by different exercise intensities in individuals with low and high levels of physical fitness. In athletes, therefore, high-intensity exercise may be required to increase circulating sex steroid hormone concentrations. PMID:26518151

  16. Nutrition in the adolescent.

    PubMed

    Wahl, R

    1999-02-01

    This article reviews the nutritional requirements of puberty and the clinical assessment of nutritional status, and discusses the nutritional risks imposed by vegetarian diets, pregnancy, and athletic involvement. Energy (calories) and protein are essential in pubertal development. Adolescent females require approximately 2200 calories/day, whereas male adolescents require 2500-3000 calories/day. Additional intake requirements include fat, calcium, iron, zinc, vitamins, and fiber. The clinical assessment of nutritional status begins with obtaining a good diet history of the patient and this could be offered by the body mass index. Nutritional deficiencies and poor eating habits established during adolescence can have long-term consequences, including delayed sexual maturation, loss of final adult height, osteoporosis, hyperlipidemia, and obesity. As for vegetarian adolescents, nutritional risks include lack of iodine, vitamin B12, vitamin D, and some essential fatty acids. In addition, substances in some grains reduce gut absorption, thus increasing mineral deficiencies. Pregnancy may also be a risk factor for poor nutrition during adolescence. A pregnant adolescent has different nutritional needs because she is still growing. Among adolescent athletes many are turning to nutritional supplements in an attempt to improve athletic performance. A balanced, varied diet provides adequate calories and nutrition to meet the needs of most adolescents. They also have greater water needs than do adult athletes. Details on adolescent health concerns are further discussed in this article. PMID:10036686

  17. Sprint swimming performance of wild bull trout (Salvelinus confluentus)

    USGS Publications Warehouse

    Mesa, M.G.; Phelps, J.; Weiland, L.K.

    2008-01-01

    We conducted laboratory experiments to determine the sprint swimming performance of wild juvenile and adult bull trout Salvelinus confluentus. Sprint swimming speeds were estimated using high-speed digital video analysis. Thirty two bull trout were tested in sizes ranging from about 10 to 31 cm. Of these, 14 fish showed at least one motivated, vigorous sprint. When plotted as a function of time, velocity of fish increased rapidly with the relation linear or slightly curvilinear. Their maximum velocity, or Vmax, ranged from 1.3 to 2.3 m/s, was usually achieved within 0.8 to 1.0 s, and was independent of fish size. Distances covered during these sprints ranged from 1.4 to 2.4 m. Our estimates of the sprint swimming performance are the first reported for this species and may be useful for producing or modifying fish passage structures that allow safe and effective passage of fish without overly exhausting them. ?? 2008 by the Northwest Scientific Association. All rights reserved.

  18. The Effects of Muscular Fatigue on the Kinetics of Sprint Running.

    ERIC Educational Resources Information Center

    Sprague, Paul; Mann, Ralph V.

    1983-01-01

    To compare the kinematic and kinetic effects of fatigue on the biomechanics of sprint running, male subjects were filmed performing a short maximal exertion sprint and a long fatiguing sprint. Observable differences in the productive muscular activity of the better and the poorer sprinters occurred during the ground-phase of their strides.…

  19. Combined inhalation of beta2 -agonists improves swim ergometer sprint performance but not high-intensity swim performance.

    PubMed

    Kalsen, A; Hostrup, M; Bangsbo, J; Backer, V

    2014-10-01

    There is a high prevalence of asthma and airway hyperresponsiveness (AHR) in elite athletes, which leads to a major use of beta2 -agonists. In a randomized double-blinded crossover study, we investigated the effects of combined inhalation of beta2 -agonists (salbutamol, formoterol, and salmeterol), in permitted doses within the World Anti-Doping Agency 2013 prohibited list, in elite swimmers with (AHR, n = 13) or without (non-AHR, n = 17) AHR. Maximal voluntary isometric contraction of m. quadriceps (MVC), sprint performance on a swim ergometer and performance in an exhaustive swim test at 110% of VO2max were determined. Venous plasma interleukin-6 (IL-6) and interleukin-8 (IL-8) were measured post-exercise. No improvement was observed in the exhaustive swim test, but swim ergometer sprint time was improved (P < 0.05) in both groups from 57 ± 1.7 to 56 ± 1.8 s in AHR and 58.3 ± 1 to 57.4 ± 1 s in non-AHR. MVC and post-exercise plasma IL-6 increased (P < 0.05) with beta2 -agonists in both groups, whereas IL-8 only increased in AHR. In summary, inhalation of beta2 -agonists, in permitted doses, did not improve swim performance in elite swimmers. However, swim ergometer sprint performance and MVC were increased, which should be considered when making future anti-doping regulations. PMID:23834392

  20. Segment-interaction in sprint start: Analysis of 3D angular velocity and kinetic energy in elite sprinters.

    PubMed

    Slawinski, J; Bonnefoy, A; Ontanon, G; Leveque, J M; Miller, C; Riquet, A; Chèze, L; Dumas, R

    2010-05-28

    The aim of the present study was to measure during a sprint start the joint angular velocity and the kinetic energy of the different segments in elite sprinters. This was performed using a 3D kinematic analysis of the whole body. Eight elite sprinters (10.30+/-0.14s 100 m time), equipped with 63 passive reflective markers, realised four maximal 10 m sprints start on an indoor track. An opto-electronic Motion Analysis system consisting of 12 digital cameras (250 Hz) was used to collect the 3D marker trajectories. During the pushing phase on the blocks, the 3D angular velocity vector and its norm were calculated for each joint. The kinetic energy of 16 segments of the lower and upper limbs and of the total body was calculated. The 3D kinematic analysis of the whole body demonstrated that joints such as shoulders, thoracic or hips did not reach their maximal angular velocity with a movement of flexion-extension, but with a combination of flexion-extension, abduction-adduction and internal-external rotation. The maximal kinetic energy of the total body was reached before clearing block (respectively, 537+/-59.3 J vs. 514.9+/-66.0 J; p< or =0.01). These results suggested that a better synchronization between the upper and lower limbs could increase the efficiency of pushing phase on the blocks. Besides, to understand low interindividual variances in the sprint start performance in elite athletes, a 3D complete body kinematic analysis shall be used. PMID:20226465

  1. Physical Demands of Sprinting in Professional Road Cycling.

    PubMed

    Menaspà, P; Quod, M; Martin, D T; Peiffer, J J; Abbiss, C R

    2015-11-01

    The aim of this study was to quantify the demands of road competitions ending with sprints in male professional cycling. 17 races finished with top-5 results from 6 male road professional cyclists (age, 27.0±3.8 years; height, 1.76±0.03 m; weight, 71.7±1.1 kg) were analysed. SRM power meters were used to monitor power output, cadence and speed. Data were averaged over the entire race, different durations prior to the sprint (60, 10, 5 and 1 min) and during the actual sprint. Variations in power during the final 10 min of the race were quantified using exposure variation analysis. This observational study was conducted in the field to maximize the ecological validity of the results. Power, cadence and speed were statistically different between various phases of the race (p<0.001), increasing from 316±43 W, 95±4 rpm and 50.5±3.3 km·h(-1) in the last 10 min, to 487±58 W, 102±6 rpm and 55.4±4.7 km·h(-1) in the last min prior to the sprint. Peak power during the sprint was 17.4±1.7 W·kg(-1). Exposure variation analysis revealed a significantly greater number of short-duration high-intensity efforts in the final 5 min of the race, compared with the penultimate 5 min (p=0.010). These findings quantify the power output requirements associated with high-level sprinting in men's professional road cycling and highlight the need for both aerobic and anaerobic fitness. PMID:26252551

  2. Physiology of wheelchair racing in athletes with spinal cord injury.

    PubMed

    Bhambhani, Yagesh

    2002-01-01

    Wheelchair racing is one of the most popular sporting activities of individuals with spinal cord injury. Athletes with this impairment have unique changes in metabolic, cardiorespiratory, neuromuscular and thermoregulatory systems, which reduce their overall physiological capacity compared with able-bodied individuals or individuals with other types of impairments. This review on spinal cord injury: presents the International Stoke Mandeville Games Federation classification of wheelchair athletes; describes methods commonly used to characterise anaerobic and aerobic fitness; presents the findings of physiological studies that have evaluated wheelchair racing performance; identifies the risks associated with temperature regulation when competing in wheelchair races; and discusses special conditions that can influence wheelchair racing performance. Currently there is limited research that has examined the relationship between sprint or distance wheelchair racing performance and the anaerobic and aerobic components of physical fitness. Although the descriptive evidence indicates that the profiles of these athletes reflect their training and participation in these specific events, the association between their physiological profiles and real or simulated racing performance is unclear. The generally accepted concept that high values of aerobic and anaerobic power are strongly correlated with endurance and sprint racing performance, respectively, are not necessarily true in this population. Athletes with spinal cord injury have an impaired thermoregulatory capacity, because the compromised autonomic and somatic nervous system functions disrupt control of skin blood flow and sweating below the level of the lesion. As a result, they may be more susceptible to hyperthermia during distance wheelchair racing performance. Wheelchair athletes should follow recommendations advocated for able-bodied individuals to minimise their risks of heat stress during competition. Many

  3. Detecting growth hormone misuse in athletes.

    PubMed

    Holt, Richard I G

    2013-10-01

    Athletes have been misusing growth hormone (GH) for its anabolic and metabolic effects since the early 1980s, at least a decade before endocrinologists began to treat adults with GH deficiency. Although there is an ongoing debate about whether GH is performance enhancing, recent studies suggest that GH improves strength and sprint capacity, particularly when combined with anabolic steroids. The detection of GH misuse is challenging because it is an endogenous hormone. Two approaches have been developed to detect GH misuse; the first is based on the measurement of pituitary GH isoforms and the ratio of 22-kDa isoform to total GH. The second is based on the measurement of insulin like growth factor-I (IGF-I) and N-terminal propeptide of type III procollagen (P-III-NP) which increase in a dose-dependent manner in response to GH administration. Both methodologies have been approved by the World Anti-Doping Agency (WADA) and have led to the detection of a number of athletes misusing GH. PMID:24251151

  4. Sport Opportunities for Athletes with Disabilities.

    ERIC Educational Resources Information Center

    Journal of Physical Education, Recreation & Dance, 1984

    1984-01-01

    This series outlines sport opportunities for athletes with disabilities. Included are articles discussing sports for athletes with cerebral palsy, deaf athletes, blind athletes, wheelchair bound athletes, amputee athletes, as well as a discussion of the Special Olympics. (JMK)

  5. An SNP within the Angiotensin-Converting Enzyme Distinguishes between Sprint and Distance Performing Alaskan Sled Dogs in a Candidate Gene Analysis

    PubMed Central

    Huson, Heather J.; Byers, Alexandra M.; Runstadler, Jonathan

    2011-01-01

    The Alaskan sled dog offers a unique mechanism for studying the genetics of elite athletic performance. They are a group of mixed breed dogs, comprised of multiple common breeds, and a unique breed entity seen only as a part of the sled dog mix. Alaskan sled dogs are divided into 2 primary groups as determined by their racing skills. Distance dogs are capable of running over 1000 miles in 10 days, whereas sprint dogs run much shorter distances, approximately 30 miles, but in faster times, that is, 18–25 mph. Finding the genes that distinguish these 2 types of performers is likely to illuminate genetic contributors to human athletic performance. In this study, we tested for association between polymorphisms in 2 candidate genes; angiotensin-converting enzyme (ACE) and myostatin (MSTN) and enhanced speed and endurance performance in 174 Alaskan sled dogs. We observed 81 novel genetic variants within the ACE gene and 4 within the MSTN gene, including a polymorphism within the ACE gene that significantly (P value 2.38 × 10−5) distinguished the sprint versus distance populations. PMID:21846742

  6. Nutrition and athletic performance

    MedlinePlus

    Nutrition can help enhance athletic performance. An active lifestyle and exercise routine, along with eating well, is ... al. American College of Sports Medicine position stand. Nutrition and athletic performance. Med Sci Sports Exerc . 2009 ...

  7. Athlete's Foot (Tinea Pedis)

    MedlinePlus

    ... The most common locations for athlete's foot include: Spaces (webs) between the toes, especially between the 4th ... no worm involved.) Between the toes (the interdigital spaces), athlete's foot may appear as inflamed, scaly, and ...

  8. Feeding Your Child Athlete

    MedlinePlus

    ... snacks. The child athlete, however, will have higher energy and fluid requirements. Kids and teens who are ... consume more food to keep up with increased energy demands. Most athletes will naturally eat the right ...

  9. National Athletic Trainers' Association

    MedlinePlus

    ... represent, engage and foster the continued growth and development of the athletic training profession and athletic trainers as unique health care providers. Professional Development Center Use the free CEUs that come with ...

  10. Athletic Identity, Vocational Identity, and Occupational Engagement in College Student-Athletes and Non-Athletes

    ERIC Educational Resources Information Center

    Hook, Lacole L.

    2012-01-01

    Athletic departments in National Collegiate Athletic Association Football Bowl Subdivision universities provide academic support services to their student-athletes. Even though student-athletes receive help including career assistance from academic counselors, some studies have found that student-athletes are behind non-athletes in career…

  11. Performance Enhancing Diets and the PRISE Protocol to Optimize Athletic Performance

    PubMed Central

    Arciero, Paul J.; Ward, Emery

    2015-01-01

    The training regimens of modern-day athletes have evolved from the sole emphasis on a single fitness component (e.g., endurance athlete or resistance/strength athlete) to an integrative, multimode approach encompassing all four of the major fitness components: resistance (R), interval sprints (I), stretching (S), and endurance (E) training. Athletes rarely, if ever, focus their training on only one mode of exercise but instead routinely engage in a multimode training program. In addition, timed-daily protein (P) intake has become a hallmark for all athletes. Recent studies, including from our laboratory, have validated the effectiveness of this multimode paradigm (RISE) and protein-feeding regimen, which we have collectively termed PRISE. Unfortunately, sports nutrition recommendations and guidelines have lagged behind the PRISE integrative nutrition and training model and therefore limit an athletes' ability to succeed. Thus, it is the purpose of this review to provide a clearly defined roadmap linking specific performance enhancing diets (PEDs) with each PRISE component to facilitate optimal nourishment and ultimately optimal athletic performance. PMID:25949823

  12. The Foundation of Athletics

    ERIC Educational Resources Information Center

    Curry, Tom

    2012-01-01

    As a coach, this author likes to share some thoughts on children and sports. After 42 years in athletics in all capacities--coach, athletic director, official, parent, athlete, and observer--he can easily say he has seen, heard, or experienced it all. Each experience has helped him gain some insights on youth and interscholastic sports. Parent of…

  13. Who Are Student Athletes?

    ERIC Educational Resources Information Center

    Watt, Sherry K.; Moore, James L., III

    2001-01-01

    Describes and discusses student athletes' experiences and their environments from historical and current perspectives. Provides recommendations for student affairs professionals who wish to assist student athletes in reducing the tension between the students' academic and athletic worlds. (Contains 38 references.) (GCP)

  14. Women in Athletic Leadership

    ERIC Educational Resources Information Center

    Moore, Sandra L.; Gilmour, Suzanne L.; Kinsella, Mary P.

    2005-01-01

    Despite significant increased participation opportunities for girls and women in sport following the passage of Title IX, women remain underrepresented in athletic leadership roles. Thirty eight female and 158 male high school athletic directors responded to a 19-item Athletic Director Survey (ADS) designed to elicit information on the following:…

  15. The Student Athlete Experience

    ERIC Educational Resources Information Center

    Gayles, Joy Gaston

    2009-01-01

    Prior to the 1980s, the literature on the experiences of collegiate student athletes was rather scarce. Since that time the National Collegiate Athletic Association (NCAA) has passed several eligibility rules to address concerns about the academic performance and the overall experience of student athletes on college campuses. As such, the…

  16. Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises

    PubMed Central

    Loturco, Irineu; Pereira, Lucas Adriano; Kobal, Ronaldo; Maldonado, Thiago; Piazzi, Alessandro Fromer; Bottino, Altamiro; Kitamura, Katia; Cal Abad, Cesar Cavinato; de Arruda, Miguel; Nakamura, Fabio Yuzo

    2016-01-01

    Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG). Both groups undertook 12 power-oriented sessions, using solely JS or OPP exercises. Pre- and post-6 weeks of training, athletes performed squat jump (SJ), countermovement jump (CMJ), sprinting speed (5, 10, 20 and 30 m), change of direction (COD) and speed tests. To calculate the transfer effect coefficient (TEC) between JS and MPP OPP and the speed in 5, 10, 20, and 30 m, the ratio between the result gain (effect size [ES]) in the untrained exercise and result gain in the trained exercise was calculated. Magnitude based inference and ES were used to test the meaningful effects. The TEC between JS and VEL 5, 10, 20, and 30 m ranged from 0.77 to 1.29, while the only TEC which could be calculated between OPP and VEL 5 was rather low (0.2). In addition, the training effects of JS on jumping and speed related abilities were superior (ES ranging from small to large) to those caused by OPP (trivial ES). To conclude, the JS exercise is superior to the OPP for improving speed-power abilities in elite young soccer players. PMID:27100085

  17. Improving Sprint Performance in Soccer: Effectiveness of Jump Squat and Olympic Push Press Exercises.

    PubMed

    Loturco, Irineu; Pereira, Lucas Adriano; Kobal, Ronaldo; Maldonado, Thiago; Piazzi, Alessandro Fromer; Bottino, Altamiro; Kitamura, Katia; Cal Abad, Cesar Cavinato; de Arruda, Miguel; Nakamura, Fabio Yuzo

    2016-01-01

    Training at the optimum power load (OPL) is an effective way to improve neuromuscular abilities of highly trained athletes. The purpose of this study was to test the effects of training using the jump squat (JS) or Olympic push-press (OPP) exercises at the OPL during a short-term preseason on speed-power related abilities in high-level under-20 soccer players. The players were divided into two training groups: JS group (JSG) and OPP group (OPPG). Both groups undertook 12 power-oriented sessions, using solely JS or OPP exercises. Pre- and post-6 weeks of training, athletes performed squat jump (SJ), countermovement jump (CMJ), sprinting speed (5, 10, 20 and 30 m), change of direction (COD) and speed tests. To calculate the transfer effect coefficient (TEC) between JS and MPP OPP and the speed in 5, 10, 20, and 30 m, the ratio between the result gain (effect size [ES]) in the untrained exercise and result gain in the trained exercise was calculated. Magnitude based inference and ES were used to test the meaningful effects. The TEC between JS and VEL 5, 10, 20, and 30 m ranged from 0.77 to 1.29, while the only TEC which could be calculated between OPP and VEL 5 was rather low (0.2). In addition, the training effects of JS on jumping and speed related abilities were superior (ES ranging from small to large) to those caused by OPP (trivial ES). To conclude, the JS exercise is superior to the OPP for improving speed-power abilities in elite young soccer players. PMID:27100085

  18. The effect of weight loss by ketogenic diet on the body composition, performance-related physical fitness factors and cytokines of Taekwondo athletes

    PubMed Central

    Rhyu, Hyun-seung; Cho, Su-Youn

    2014-01-01

    The purpose of this study was to investigate the effects of the weight loss through 3 weeks of ketogenic diet on performance-related physical fitness and inflammatory cytokines in Taekwondo athletes. The subjects selected for this research were 20 Taekwondo athletes of the high schools who participated in a summer camp training program. The subjects were randomly assigned to 2 groups, 10 subjects to each group: the ketogenic diet (KD) group and the non-ketogenic diet (NKD) group. Body composition, performance-related physical fitness factors (2,000 m sprint, Wingate test, grip force, back muscle strength, sit-up, 100 m sprint, standing broad jump, single leg standing) and cytokines (Iinterleukin-6, Interferon-γ, tumor necrosis factor-α) were analyzed before and after 3weeks of ketogenic diet. No difference between the KD and NKD groups in weight, %body fat, BMI and fat free mass. However, the KD group, compared to the NKD group, finished 2,000 m sprint in less time after weight loss, and also felt less fatigue as measured by the Wingate test and showed less increase in tumor necrosis factor-α. This result suggests that KD diet can be helpful for weight category athletes, such as Taekwondo athletes, by improving aerobic capacity and fatigue resistance capacity, and also by exerting positive effect on inflammatory response. PMID:25426472

  19. The effect of weight loss by ketogenic diet on the body composition, performance-related physical fitness factors and cytokines of Taekwondo athletes.

    PubMed

    Rhyu, Hyun-Seung; Cho, Su-Youn

    2014-10-01

    The purpose of this study was to investigate the effects of the weight loss through 3 weeks of ketogenic diet on performance-related physical fitness and inflammatory cytokines in Taekwondo athletes. The subjects selected for this research were 20 Taekwondo athletes of the high schools who participated in a summer camp training program. The subjects were randomly assigned to 2 groups, 10 subjects to each group: the ketogenic diet (KD) group and the non-ketogenic diet (NKD) group. Body composition, performance-related physical fitness factors (2,000 m sprint, Wingate test, grip force, back muscle strength, sit-up, 100 m sprint, standing broad jump, single leg standing) and cytokines (Iinterleukin-6, Interferon-γ, tumor necrosis factor-α) were analyzed before and after 3weeks of ketogenic diet. No difference between the KD and NKD groups in weight, %body fat, BMI and fat free mass. However, the KD group, compared to the NKD group, finished 2,000 m sprint in less time after weight loss, and also felt less fatigue as measured by the Wingate test and showed less increase in tumor necrosis factor-α. This result suggests that KD diet can be helpful for weight category athletes, such as Taekwondo athletes, by improving aerobic capacity and fatigue resistance capacity, and also by exerting positive effect on inflammatory response. PMID:25426472

  20. Running-based Anaerobic Sprint Test as a Procedure to Evaluate Anaerobic Power.

    PubMed

    Andrade, V L; Zagatto, A M; Kalva-Filho, C A; Mendes, O C; Gobatto, C A; Campos, E Z; Papoti, M

    2015-12-01

    The aim of this study was to evaluate the use of the running anaerobic sprint test (RAST) as a predictor of anaerobic capacity, compare it to the maximal accumulated oxygen deficit (MAOD) and to compare the RAST's parameters with the parameters of 30-s all-out tethered running on a treadmill. 39 (17.0±1.4 years) soccer players participated in this study. The participants underwent an incremental test, 10 submaximal efforts [50-95% of velocity correspondent to VO(2MAX) (vVO(2MAX))] and one supramaximal effort at 110% of vVO(2MAX) for the determination of MAOD. Furthermore, the athletes performed the RAST. In the second stage the 30-s all-out tethered running was performed on a treadmill (30-s all-out), and compared with RAST. No significant correlation was observed between MAOD and RAST parameters. However, significant correlations were found between the power of the fifth effort (P5) of RAST with peak and mean power of 30-s all-out (r=0.73 and 0.50; p<0.05, respectively). In conclusion, the parameters from RAST do not have an association with MAOD, suggesting that this method should not be used to evaluate anaerobic capacity. Although the correlations between RAST parameters with 30-s all-out do reinforce the RAST as an evaluation method of anaerobic metabolism, such as anaerobic power. PMID:26422055

  1. Combined glucose ingestion and mouth rinsing improves sprint cycling performance.

    PubMed

    Chong, Edwin; Guelfi, Kym J; Fournier, Paul A

    2014-12-01

    This study investigated whether combined ingestion and mouth rinsing with a carbohydrate solution could improve maximal sprint cycling performance. Twelve competitive male cyclists ingested 100 ml of one of the following solutions 20 min before exercise in a randomized double-blinded counterbalanced order (a) 10% glucose solution, (b) 0.05% aspartame solution, (c) 9.0% maltodextrin solution, or (d) water as a control. Fifteen min after ingestion, repeated mouth rinsing was carried out with 11 × 15 ml bolus doses of the same solution at 30-s intervals. Each participant then performed a 45-s maximal sprint effort on a cycle ergometer. Peak power output was significantly higher in response to the glucose trial (1188 ± 166 W) compared with the water (1036 ± 177 W), aspartame (1088 ± 128 W) and maltodextrin (1024 ± 202 W) trials by 14.7 ± 10.6, 9.2 ± 4.6 and 16.0 ± 6.0% respectively (p < .05). Mean power output during the sprint was significantly higher in the glucose trial compared with maltodextrin (p < .05) and also tended to be higher than the water trial (p = .075). Glucose and maltodextrin resulted in a similar increase in blood glucose, and the responses of blood lactate and pH to sprinting did not differ significantly between treatments (p > .05). These findings suggest that combining the ingestion of glucose with glucose mouth rinsing improves maximal sprint performance. This ergogenic effect is unlikely to be related to changes in blood glucose, sweetness, or energy sensing mechanisms in the gastrointestinal tract. PMID:24668608

  2. Effects of vest loading on sprint kinetics and kinematics.

    PubMed

    Cross, Matt R; Brughelli, Matt E; Cronin, John B

    2014-07-01

    The effects of vest loading on sprint kinetics and kinematics during the acceleration and maximum velocity phases of sprinting are relatively unknown. A repeated measures analysis of variance with post hoc contrasts was used to determine whether performing 6-second maximal exertion sprints on a nonmotorized force treadmill, under 2 weighted vest loading conditions (9 and 18 kg) and an unloaded baseline condition, affected the sprint mechanics of 13 males from varying sporting backgrounds. Neither vest load promoted significant change in peak vertical ground reaction force (GRF-z) outputs compared with baseline during acceleration, and only 18-kg loading increased GRF-z at the maximum velocity (8.8%; effect size [ES] = 0.70). The mean GRF-z significantly increased with 18-kg loading during acceleration and maximum velocity (11.8-12.4%; ES = 1.17-1.33). Horizontal force output was unaffected, although horizontal power was decreased with the 18-kg vest during maximum velocity (-14.3%; ES = -0.48). Kinematic analysis revealed decreasing velocity (-3.6 to -5.6%; ES = -0.38 to -0.61), decreasing step length (-4.2%; ES = -0.33 to -0.34), increasing contact time (5.9-10.0%; ES = 1.01-1.71), and decreasing flight time (-17.4 to -26.7%; ES = -0.89 to -1.50) with increased loading. As a vertical vector-training stimulus, it seems that vest loading decreases flight time, which in turn reduces GRF-z. Furthermore, it seems that heavier loads than that are traditionally recommended are needed to promote increases in the GRF-z output during maximum velocity sprinting. Finally, vest loading offers little as a horizontal vector-training stimulus and actually compromises horizontal power output. PMID:24378661

  3. Scapula behavior associates with fast sprinting in first accelerated running.

    PubMed

    Otsuka, Mitsuo; Ito, Taisuke; Honjo, Toyoyuki; Isaka, Tadao

    2016-01-01

    The arm-swing motion is important for coordinated lower limb movement during a fast sprint and is composed of three-dimensional scapulothoracic and glenohumeral joint motion. Here, we aimed to clarify the role of the scapula during the initiation of a sprint running when sprinter run with high horizontal acceleration. Ten sports-active students participated in four 5-m dashes, with scapular constraint using non-elastic therapy tape (constraint condition) and without scapular constraint (free condition). The sprinting kinematics was assessed by a 16-camera motion capture system. In the constraint condition, the 2-m sprint time was significantly longer than that in the free condition. At the instants of foot-contact and take-off during the first step, no significant difference in the humerothoracic flexion angle was seen between these two conditions. In contrast, at the instants of foot-contact and take-off during the first step, the humerothoracic extension angle in the constraint condition was significantly smaller than that in the free condition. The forward leaning vector angle of center of mass during the first step was significantly greater than that in the constraint condition. Although no significant difference in hip extension and foot forward leaning angles was seen at the instant of foot contact during the first step between the two conditions, at the instant of take-off, the hip extension and foot forward leaning angles in the constraint condition were significantly smaller than those in the free condition. Therefore, scapular behavior in first accelerated running contributes to larger upper- and lower-limb motions and facilitates coordinating whole-body balance for a fast sprint. PMID:27350917

  4. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting.

    PubMed

    Girard, Olivier; Brocherie, Franck; Millet, Grégoire P

    2016-01-01

    We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s "all-out" sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; "fast" instruction) and maximal (~5 s; "hard" instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, -50, -100, and -200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (-8 ± 4% and 178 ± 11 m) but not in LA (-7 ± 3% and 181 ± 10 m) compared to NM (-5 ± 2% and 183 ± 9 m). Compared to NM (-9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (-14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (-6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (-8 ± 11%; P = 0.07) and RF (-14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0-100 (-8 ± 9%) and 0-200 ms (-10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values. Additionally, the EMG rise for VL muscle was similar

  5. High Altitude Increases Alteration in Maximal Torque but Not in Rapid Torque Development in Knee Extensors after Repeated Treadmill Sprinting

    PubMed Central

    Girard, Olivier; Brocherie, Franck; Millet, Grégoire P.

    2016-01-01

    We assessed knee extensor neuromuscular adjustments following repeated treadmill sprints in different normobaric hypoxia conditions, with special reference to rapid muscle torque production capacity. Thirteen team- and racquet-sport athletes undertook 8 × 5-s “all-out” sprints (passive recovery = 25 s) on a non-motorized treadmill in normoxia (NM; FiO2 = 20.9%), at low (LA; FiO2 = 16.8%) and high (HA; FiO2 = 13.3%) normobaric hypoxia (simulated altitudes of ~1800 m and ~3600 m, respectively). Explosive (~1 s; “fast” instruction) and maximal (~5 s; “hard” instruction) voluntary isometric contractions (MVC) of the knee extensors (KE), with concurrent electromyographic (EMG) activity recordings of the vastus lateralis (VL) and rectus femoris (RF) muscles, were performed before and 1-min post-exercise. Rate of torque development (RTD) and EMG (i.e., Root Mean Square or RMS) rise from 0 to 30, −50, −100, and −200 ms were recorded, and were also normalized to maximal torque and EMG values, respectively. Distance covered during the first 5-s sprint was similar (P > 0.05) in all conditions. A larger (P < 0.05) sprint decrement score and a shorter (P < 0.05) cumulated distance covered over the eight sprints occurred in HA (−8 ± 4% and 178 ± 11 m) but not in LA (−7 ± 3% and 181 ± 10 m) compared to NM (−5 ± 2% and 183 ± 9 m). Compared to NM (−9 ± 7%), a larger (P < 0.05) reduction in MVC torque occurred post-exercise in HA (−14 ± 9%) but not in LA (-12 ± 7%), with no difference between NM and LA (P > 0.05). Irrespectively of condition (P > 0.05), peak RTD (−6 ± 11%; P < 0.05), and normalized peak RMS activity for VL (−8 ± 11%; P = 0.07) and RF (−14 ± 11%; P < 0.01) muscles were reduced post-exercise, whereas reductions (P < 0.05) in absolute RTD occurred within the 0–100 (−8 ± 9%) and 0–200 ms (−10 ± 8%) epochs after contraction onset. After normalization to MVC torque, there was no difference in RTD values

  6. Hypertension in the athlete.

    PubMed

    Sachtleben, Thomas; Fields, Karl B

    2003-04-01

    Athletes with hypertension are frequently encountered in clinical settings and during preparticipation examinations. This common condition merits special attention in athletes, as they have particular physiologic and sport-specific demands. Awareness of the pressor response to both isometric and isotonic exercise is valuable in managing hypertensive athletes. Recommendations regarding physical activity in hypertensive patients and clearance for sports participation among competitive athletes are reviewed. Nonpharmacologic measures and the use of customary antihypertensives in athletes is essential. However, knowledge of side-effect profiles and possible negative effects on exercise tolerance guide appropriate medication choices. PMID:12831663

  7. Update on the female athlete triad.

    PubMed

    Barrack, Michelle T; Ackerman, Kathryn E; Gibbs, Jenna C

    2013-06-01

    Updated prevalence estimates of all 3 components of the Female Athlete Triad, a syndrome characterized by low energy availability, functional hypothalamic amenorrhea, and osteoporosis, is low (0 %-16 %), however, estimates of 1 or 2 concurrent components approach 50 %-60 % among certain athlete groups. Recent research identifies components of the Triad among female adolescent athletes, particularly those participating in leanness sports, such as endurance running. This is alarming, as adolescents require adequate nutrition and normal hormone function to optimize bone mineral gains during this critical developmental period. Current literature highlights new assessments, such as measurements of bone microarchitecture and hormone levels to better evaluate bone strength and the hormonal and metabolic profile of athletes with and at risk for the Triad. Recent data also provides support for additional potential consequences of the Triad, such as endothelial dysfunction and related cardiovascular effects, stress fractures, and musculoskeletal injuries. Additional prospective research is needed to evaluate long-term indicators and consequences of the Triad and identify effective behavioral treatment strategies. PMID:23613226

  8. Anthropometric, Sprint, and High-Intensity Running Profiles of English Academy Rugby Union Players by Position.

    PubMed

    Darrall-Jones, Joshua D; Jones, Ben; Till, Kevin

    2016-05-01

    The purpose of this study was to evaluate the anthropometric, sprint, and high-intensity running profiles of English academy rugby union players by playing positions, and to investigate the relationships between anthropometric, sprint, and high-intensity running characteristics. Data were collected from 67 academy players after the off-season period and consisted of anthropometric (height, body mass, sum of 8 skinfolds [∑SF]), 40-m linear sprint (5-, 10-, 20-, and 40-m splits), the Yo-Yo intermittent recovery test level 1 (Yo-Yo IRTL-1), and the 30-15 intermittent fitness test (30-15 IFT). Forwards displayed greater stature, body mass, and ∑SF; sprint times and sprint momentum, with lower high-intensity running ability and sprint velocities than backs. Comparisons between age categories demonstrated body mass and sprint momentum to have the largest differences at consecutive age categories for forwards and backs; whereas 20-40-m sprint velocity was discriminate for forwards between under 16s, 18s, and 21s. Relationships between anthropometric, sprint velocity, momentum, and high-intensity running ability demonstrated body mass to negatively impact on sprint velocity (10 m; r = -0.34 to -0.46) and positively affect sprint momentum (e.g., 5 m; r = 0.85-0.93), with large to very large negative relationships with the Yo-Yo IRTL-1 (r = -0.65 to -0.74) and 30-15 IFT (r = -0.59 to -0.79). These findings suggest that there are distinct anthropometric, sprint, and high-intensity running ability differences between and within positions in junior rugby union players. The development of sprint and high-intensity running ability may be impacted by continued increases in body mass as there seems to be a trade-off between momentum, velocity, and the ability to complete high-intensity running. PMID:26466132

  9. Cooling athletes with a spinal cord injury.

    PubMed

    Griggs, Katy E; Price, Michael J; Goosey-Tolfrey, Victoria L

    2015-01-01

    Cooling strategies that help prevent a reduction in exercise capacity whilst exercising in the heat have received considerable research interest over the past 3 decades, especially in the lead up to a relatively hot Olympic and Paralympic Games. Progressing into the next Olympic/Paralympic cycle, the host, Rio de Janeiro, could again present an environmental challenge for competing athletes. Despite the interest and vast array of research into cooling strategies for the able-bodied athlete, less is known regarding the application of these cooling strategies in the thermoregulatory impaired spinal cord injured (SCI) athletic population. Individuals with a spinal cord injury (SCI) have a reduced afferent input to the thermoregulatory centre and a loss of both sweating capacity and vasomotor control below the level of the spinal cord lesion. The magnitude of this thermoregulatory impairment is proportional to the level of the lesion. For instance, individuals with high-level lesions (tetraplegia) are at a greater risk of heat illness than individuals with lower-level lesions (paraplegia) at a given exercise intensity. Therefore, cooling strategies may be highly beneficial in this population group, even in moderate ambient conditions (~21 °C). This review was undertaken to examine the scientific literature that addresses the application of cooling strategies in individuals with an SCI. Each method is discussed in regards to the practical issues associated with the method and the potential underlying mechanism. For instance, site-specific cooling would be more suitable for an athlete with an SCI than whole body water immersion, due to the practical difficulties of administering this method in this population group. From the studies reviewed, wearing an ice vest during intermittent sprint exercise has been shown to decrease thermal strain and improve performance. These garments have also been shown to be effective during exercise in the able-bodied. Drawing on

  10. Physiological and psychological correlates of success in track and field athletes.

    PubMed Central

    Thomas, T. R.; Zebas, C. J.; Bahrke, M. S.; Araujo, J.; Etheridge, G. L.

    1983-01-01

    Twenty-four collegiate distance runners and 20 power athletes (sprinters and jumpers) of various success levels were tested on a number of physiological and psychological parameters. Multiple regression analysis indicated that physiological factors could explain over 81% of the variance related to successful distance running while physiological and psychological factors could explain over 80% of the of the variance related to successful sprinting and jumping. Body weight, fibre type, low density lipoprotein-cholesterol, and hamstring strength were significant singular correlates to successful distance running. Year in school, percent body fat, quadriceps strength, and leg muscle balance were significant single correlates to successful sprinting and jumping performance. Images p102-a p102-b p102-c p102-d p102-e PMID:6883017

  11. Charlie's Words: Supporting Gifted Male Athletes Using Athletes' Journals

    ERIC Educational Resources Information Center

    Kent, Richard

    2012-01-01

    A gifted student-athlete, Charlie Bloomfield is introduced to athlete's journals by his coaches at Burke Mountain Academy (Vermont), an elite American ski school. Used by Olympians and professionals alike, journals provide athletes with ways to organize and reflect on training and competitions. Athlete's journals help gifted male athletes address…

  12. Prevention of eating disorders in female athletes

    PubMed Central

    Coelho, Gabriela Morgado de Oliveira; Gomes, Ainá Innocencio da Silva; Ribeiro, Beatriz Gonçalves; Soares, Eliane de Abreu

    2014-01-01

    Eating disorders are serious mental diseases that frequently appear in female athletes. They are abnormal eating behaviors that can be diagnosed only by strict criteria. Disordered eating, although also characterized as abnormal eating behavior, does not include all the criteria for diagnosing eating disorders and is therefore a way to recognize the problem in its early stages. It is important to identify factors to avoid clinical progression in this high-risk population. Therefore, the purpose of this review is to discuss critical information for the prevention of eating disorders in female athletes. This review discusses the major correlates for the development of an eating disorder. We also discuss which athletes are possibly at highest risk for eating disorders, including those from lean sports and female adolescent athletes. There is an urgent need for the demystification of myths surrounding body weight and performance in sports. This review includes studies that tested different prevention programs’ effectiveness, and the majority showed positive results. Educational programs are the best method for primary prevention of eating disorders. For secondary prevention, early identification is essential and should be performed by preparticipation exams, the recognition of dietary markers, and the use of validated self-report questionnaires or clinical interviews. In addition, more randomized clinical trials are needed with athletes from multiple sports in order for the most reliable recommendations to be made and for some sporting regulations to be changed. PMID:24891817

  13. Secondary school athletes: a study of mouthguards.

    PubMed Central

    Onyeaso, Chukwudi Ochi

    2004-01-01

    The purpose of this study was to determine the extent of mouthguard awareness and use, as well as the amount and type of oro-facial trauma associated with and without mouthguard wear in adolescent Nigerian athletes. A 13-item self-completion questionnaire was completed and returned by 1,127 secondary school athletes (completion rate of 93.9%) comprising 683 (60.6%) males and 444 (39.4%) females ranging in age from 12- to 19 years (mean age 15.18+/-2.97 SD). The athletes were randomly drawn from 23 secondary schools located in different parts of Ibadan city in Nigeria. Sixty-five-and-a-third percent of the athletes professed awareness of the need for mouthguards for sports, but only 19.6% claimed usage of the device. Thirty-four-and-a-half percent of the athletes reported having sustained one form of oro-facial injury or the other previously. The prevalence of oro-facial injuries was significantly lower while wearing a mouthguard (p<0.05), and most of the injuries occurred during contact sports. The study supports the need for the enforcement of mandatory mouthguard use in contact sports. Images Figure 1 PMID:14977285

  14. Athletic coaches as violence prevention advocates.

    PubMed

    Jaime, Maria Catrina D; McCauley, Heather L; Tancredi, Daniel J; Nettiksimmons, Jasmine; Decker, Michele R; Silverman, Jay G; O'Connor, Brian; Stetkevich, Nicholas; Miller, Elizabeth

    2015-04-01

    Adolescent relationship abuse (ARA) is a significant public health problem. Coaching Boys Into Men (CBIM) is an evidence-based ARA prevention program that trains coaches to deliver violence prevention messages to male athletes. Assessing acceptability and impact of CBIM on coaches may inform prevention efforts that involve these important adults in health promotion among youth. As part of a two-armed cluster-randomized controlled trial of CBIM in 16 high schools in Northern California, coaches completed baseline and postseason surveys (n = 176) to assess their attitudes and confidence delivering the program. Coaches in the intervention arm also participated in interviews (n = 36) that explored program acceptability, feasibility, and impact. Relative to controls, intervention coaches showed increases in confidence intervening when witnessing abusive behaviors among their athletes, greater bystander intervention, and greater frequency of violence-related discussions with athletes and other coaches. Coaches reported the program was easy to implement and valuable for their athletes. Findings illustrate the value of exploring attitudinal and behavioral changes among ARA prevention implementers, and suggest that coaches can gain confidence and enact behaviors to discourage ARA among male athletes. Coaches found the program to be feasible and valuable, which suggests potential for long-term uptake and sustainability. PMID:25015237

  15. Attention Deficit Hyperactivity Disorder and Athletes

    PubMed Central

    White, Russell D.; Harris, George D.; Gibson, Margaret E.

    2014-01-01

    Context: Attention deficit hyperactivity disorder (ADHD) is common in the general population, and many individuals with this condition participate in sports activity at all competition levels. Evidence Acquisition: Related studies were selected through literature searches of PubMed, MEDLINE, and Cochrane databases for the years 1991 to 2011. Key search terms were ADD, ADHD, sports, athletes, athletics, guidelines, NCAA, WADA, IOC, college, concussion, diagnosis, management, treatment, evaluation, return-to-play, pharmacotherapy, adult, adolescent, student, screening, injury, risk, neuropsychiatry, TBI, traumatic brain injury, and epidemiology. Study Design: Literature review. Level of Evidence: Level 4. Results: ADHD usually has an early onset, with delayed diagnosis in some patients due to heterogeneous presentations. Suspected cases can be evaluated with available diagnostic tools and confirmed clinically. Athletes with ADHD may participate at all competition levels. Conclusion: Athletes with ADHD are able to participate at all competition levels by following published guidelines and requirements. Exercise benefits many athletes with ADHD. The relationship between ADHD and concussion syndromes is currently under investigation. PMID:24587866

  16. Developmental and Contextual Risks of Social Physique Anxiety among Female Athletes

    ERIC Educational Resources Information Center

    Gay, Jennifer L.; Monsma, Eva V.; Torres-McGehee, Toni M.

    2011-01-01

    In the present study, we examined developmental and contextual factors that may increase the odds of reporting higher social physique anxiety (SPA) among 404 adolescent athletes 11 to 16 years old. Findings showed older, later maturing athletes past peak height velocity and with greater body mass index (BMI) reported higher SPA. Individual…

  17. Correlates of child activity and television: The contribution of children's athletic identity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There is evidence that athletic self-concept can be both an important outcome and/or a mediating variable for physical activity in children and adolescents. However much less is known about the relationship between sedentary behaviors, such as television with athletic self-concept. This study exam...

  18. Long-Term Effects of Athletics Meet on the Perceived Competence of Individuals with Intellectual Disabilities

    ERIC Educational Resources Information Center

    Ninot, Gregory; Maiano, Christophe

    2007-01-01

    The purpose was to examine the effects of the type of athletic program (integrated versus segregated) and of the type of sport (basketball versus swimming) on two domains of perceived competence (athletic competence and social acceptance), and general self-worth. Participants were 48 adolescent females with intellectual disabilities (ID) divided…

  19. Control of propulsion and body lift during the first two stances of sprint running: a simulation study.

    PubMed

    Debaere, Sofie; Delecluse, Christophe; Aerenhouts, Dirk; Hagman, Friso; Jonkers, Ilse

    2015-01-01

    The aim of this study was to relate the contribution of lower limb joint moments and individual muscle forces to the body centre of mass (COM) vertical and horizontal acceleration during the initial two steps of sprint running. Start performance of seven well-trained sprinters was recorded using an optoelectronic motion analysis system and two force plates. Participant-specific torque-driven and muscle-driven simulations were conducted in OpenSim to quantify, respectively, the contributions of the individual joints and muscles to body propulsion and lift. The ankle is the major contributor to both actions during the first two stances, with an even larger contribution in the second compared to the first stance. Biarticular gastrocnemius is the main muscle contributor to propulsion in the second stance. The contribution of the hip and knee depends highly on the position of the athlete: During the first stance, where the athlete runs in a forward bending position, the knee contributes primarily to body lift and the hip contributes to propulsion and body lift. In conclusion, a small increase in ankle power generation seems to affect the body COM acceleration, whereas increases in hip and knee power generation tend to affect acceleration less. PMID:25798644

  20. Morphologic Features of the "Athlete's Heart" in Children: A Contemporary Review.

    PubMed

    Rowland, Thomas

    2016-08-01

    Recognizing the cardiac features of athletically trained children bears importance for health care providers and exercise physiologists alike. This literature review reveals that ventricular enlargement and/or hypertrophy are commonly observed in studies of pre- and early-adolescent endurance athletes, yet the magnitude of these features is less than that described in adult athletes. Moreover, the upper range of values in child athletes is sufficiently small that clinical confusion with findings mimicking those in individuals with heart disease should not be expected to occur. In contrast to sex differences in the "athlete's heart" in adults, cardiac structural findings in child athletes are similar in males and females. The extent that cardiac features observed in trained child athletes reflect a response to training or are influenced by genetic preselection remains uncertain. PMID:26694944

  1. Effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints

    PubMed Central

    Arimitsu, T; Yunoki, T; Kimura, T; Yamanaka, R; Yano, T

    2014-01-01

    The aim of this study was to investigate the effects of heat exposure in the absence of hyperthermia on power output during repeated cycling sprints. Seven males performed four 10-s cycling sprints interspersed by 30 s of active recovery on a cycle ergometer in hot-dry and thermoneutral environments. Changes in rectal temperature were similar under the two ambient conditions. The mean 2-s power output over the 1st–4th sprints was significantly lower under the hot-dry condition than under the thermoneutral condition. The amplitude of the electromyogram was lower under the hot-dry condition than under the thermoneutral condition during the early phase (0–3 s) of each cycling sprint. No significant difference was observed for blood lactate concentration between the two ambient conditions. Power output at the onset of a cycling sprint during repeated cycling sprints is decreased due to heat exposure in the absence of hyperthermia. PMID:25729145

  2. Optimal Balance Between Force and Velocity Differs Among World-Class Athletes.

    PubMed

    Giroux, Caroline; Rabita, Giuseppe; Chollet, Didier; Guilhem, Gaël

    2016-02-01

    Performance during human movements is highly related to force and velocity muscle capacities. Those capacities are highly developed in elite athletes practicing power-oriented sports. However, it is still unclear whether the balance between their force and velocity-generating capacities constitutes an optimal profile. In this study, we aimed to determine the effect of elite sport background on the force-velocity relationship in the squat jump, and evaluate the level of optimization of these profiles. Ninety-five elite athletes in cycling, fencing, taekwondo, and athletic sprinting, and 15 control participants performed squat jumps in 7 loading conditions (range: 0%-60% of the maximal load they were able to lift). Theoretical maximal power (Pm), force (F0), and velocity (v0) were determined from the individual force-velocity relationships. Optimal profiles were assessed by calculating the optimal force (F0th) and velocity (v0th). Athletic sprinters and cyclists produced greater force than the other groups (P < .05). F0 was significantly lower than F0th, and v0 was significantly higher than v0th for female fencers and control participants, and for male athletics sprinters, fencers, and taekwondo practitioners (P < .05). Our study shows that the chronic practice of an activity leads to differently balanced force-velocity profiles. Moreover, the differences between measured and optimal force-velocity profiles raise potential sources of performance improvement in elite athletes. PMID:26398964

  3. Sprint Conditioning of Junior Soccer Players: Effects of Training Intensity and Technique Supervision

    PubMed Central

    Haugen, Thomas; Tønnessen, Espen; Øksenholt, Øyvind; Haugen, Fredrik Lie; Paulsen, Gøran; Enoksen, Eystein; Seiler, Stephen

    2015-01-01

    The aims of the present study were to compare the effects of 1) training at 90 and 100% sprint velocity and 2) supervised versus unsupervised sprint training on soccer-specific physical performance in junior soccer players. Young, male soccer players (17 ±1 yr, 71 ±10 kg, 180 ±6 cm) were randomly assigned to four different treatment conditions over a 7-week intervention period. A control group (CON, n=9) completed regular soccer training according to their teams’ original training plans. Three training groups performed a weekly repeated-sprint training session in addition to their regular soccer training sessions performed at A) 100% intensity without supervision (100UNSUP, n=13), B) 90% of maximal sprint velocity with supervision (90SUP, n=10) or C) 90% of maximal sprint velocity without supervision (90UNSUP, n=13). Repetitions x distance for the sprint-training sessions were 15x20 m for 100UNSUP and 30x20 m for 90SUP and 90UNSUP. Single-sprint performance (best time from 15x20 m sprints), repeated-sprint performance (mean time over 15x20 m sprints), countermovement jump and Yo-Yo Intermittent Recovery Level 1 (Yo-Yo IR1) were assessed during pre-training and post-training tests. No significant differences in performance outcomes were observed across groups. 90SUP improved Yo-Yo IR1 by a moderate margin compared to controls, while all other effect magnitudes were trivial or small. In conclusion, neither weekly sprint training at 90 or 100% velocity, nor supervised sprint training enhanced soccer-specific physical performance in junior soccer players. PMID:25798601

  4. The influence of surface on the running velocities of elite and amateur orienteer athletes.

    PubMed

    Hébert-Losier, K; Jensen, K; Mourot, L; Holmberg, H-C

    2014-12-01

    We compared the reduction in running velocities from road to off-road terrain in eight elite and eight amateur male orienteer athletes to investigate whether this factor differentiates elite from amateur athletes. On two separate days, each subject ran three 2-km time trials and three 20-m sprints "all-out" on a road, on a path, and in a forest. On a third day, the running economy and maximal aerobic power of individuals were assessed on a treadmill. The elite orienteer ran faster than the amateur on all three surfaces and at both distances, in line with their better running economy and aerobic power. In the forest, the elites ran at a slightly higher percentage of their 2-km (∼3%) and 20-m (∼4%) road velocities. Although these differences did not exhibit traditional statistical significance, magnitude-based inferences suggested likely meaningful differences, particularly during 20-m sprinting. Of course, cognitive, mental, and physical attributes other than the ability to run on different surfaces are required for excellence in orienteering (e.g., a high aerobic power). However, we suggest that athlete-specific assessment of running performance on various surfaces and distances might assist in tailoring training and identifying individual strengths and/or weaknesses in an orienteer. PMID:24673160

  5. Update in the understanding of altitude-induced limitations to performance in team-sport athletes.

    PubMed

    Billaut, François; Aughey, Robert J

    2013-12-01

    The internationalism of field-based team sports (TS) such as football and rugby requires teams to compete in tournaments held at low to moderate altitude (∼1200-2500 m). In TS, acceleration, speed and aerobic endurance are physical characteristics associated with ball possession and, ultimately, scoring. While these qualities are affected by the development of neuromuscular fatigue at sea level, arterial hypoxaemia induced by exposure to altitude may further hinder the capacity to perform consecutive accelerations (CAC) or sprint endurance and thereby change the outcome of a match. The higher the altitude, the more severe the hypoxaemia, and thus, the larger the expected decline in aerobic endurance, CAC and match running performance. Therefore, it is critical for athletes and coaches to understand how arterial hypoxaemia affects aerobic endurance and CAC and the magnitude of decline they may face at altitude for optimal preparation and increased chances of success. This mini review summarises the effects of acute altitude/hypoxia exposure on aerobic endurance, CAC and activity profiles of TS athletes performing in the laboratory and during matches at natural altitude, and analyses the latest findings about the consequences of arterial hypoxaemia on the relationship between peripheral perturbations, neural adjustments and performance during repeated sprints or CAC. Finally, we briefly discuss how altitude training can potentially help athletes prepare for competition at altitude. PMID:24282202

  6. Effect of Carbohydrate Ingestion on Sprint Performance Following Continuous Exercise

    NASA Astrophysics Data System (ADS)

    Siahkohian, M.; Farhadi, H.; Naghizadeh Baghi, A.; Valizadeh, A.

    The purpose of this study was to determine the effect of 5% carbohydrate ingestion on the sprint performance immediately following 90 min of running at 70-80% of maximal heart rate reserve. Thirty young active men were selected as subjects and allocated randomly to two carbohydrate (CHO, N = 15) and placebo (PL, N = 15) groups. Pre-test 200 m dash, 90 min running and post-test 200 m dash took place, respectively. Exercise heart rate monitored during 90 min running by a cardio frequency meter. Significant differences were found between the CHO and PL post-test 200 m dash records (p<0.05). Blood glucose was found to be significantly higher at the end of the 90 min running for the CHO group than for the PL group (p<0.01). The results suggest that carbohydrate ingestion during endurance exercise inhibits failing of Sprint performance of young active men.

  7. Effects of forward trunk lean on hamstring muscle kinematics during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Takahashi, Kazumasa; Fukubayashi, Toru

    2015-01-01

    This study aimed to investigate the effects of forward trunk lean on hamstring muscle kinematics during sprinting. Eight male sprinters performed maximal-effort sprints in two trunk positions: forward lean and upright. A three-dimensional musculoskeletal model was used to compute the musculotendon lengths and velocity of the biceps femoris long head, semitendinosus, and semimembranosus muscles during the sprinting gait cycle. The musculotendon lengths of all the three hamstring muscles at foot strike and toe-off were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. In addition, a positive peak musculotendon lengthening velocity was observed in the biceps femoris long head and semimembranosus muscles during the late stance phase, and musculotendon lengths at that instant were significantly greater during the forward trunk lean sprint than during the upright trunk sprint. The present study provides significant evidence that a potential for hamstring muscle strain injury involving forward trunk lean sprinting would exist during the stance phase. The results also indicate that the biceps femoris long head and semimembranosus muscles are stretched during forward trunk lean sprinting while contracting eccentrically in the late stance phase; thus, the elongation load on these muscles could be increased. PMID:25514378

  8. Treatment of athletes.

    PubMed

    DALY, J J

    1958-06-01

    Treating participants in athletics requires the coordination of coaches, trainers, administrators and physician. Often in cases of proneness to injury, a cause can be found and correction may be obtained by further training or withdrawal of the athlete from the team. Certain types of injury should be always kept in mind in the examination of athletes, particularly football players. Ligamentous tears, myositis ossificans, navicular fracture and brain injury are injuries that may not be precisely diagnosed at the initial examination. PMID:13536862

  9. Effects of 12-Week Endurance Training at Natural Low Altitude on the Blood Redox Homeostasis of Professional Adolescent Athletes: A Quasi-Experimental Field Trial.

    PubMed

    Tong, Tomas K; Kong, Zhaowei; Lin, Hua; He, Yeheng; Lippi, Giuseppe; Shi, Qingde; Zhang, Haifeng; Nie, Jinlei

    2016-01-01

    This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n = 13 in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners. PMID:26783415

  10. Effects of 12-Week Endurance Training at Natural Low Altitude on the Blood Redox Homeostasis of Professional Adolescent Athletes: A Quasi-Experimental Field Trial

    PubMed Central

    Tong, Tomas K.; Kong, Zhaowei; Lin, Hua; He, Yeheng; Lippi, Giuseppe; Shi, Qingde; Zhang, Haifeng

    2016-01-01

    This field study investigated the influences of exposure to natural low altitude on endurance training-induced alterations of redox homeostasis in professional adolescent runners undergoing 12-week off-season conditioning program at an altitude of 1700 m (Alt), by comparison with that of their counterparts completing the program at sea-level (SL). For age-, gender-, and Tanner-stage-matched comparison, 26 runners (n = 13 in each group) were selected and studied. Following the conditioning program, unaltered serum levels of thiobarbituric acid reactive substances (TBARS), total antioxidant capacity (T-AOC), and superoxide dismutase accompanied with an increase in oxidized glutathione (GSSG) and decreases of xanthine oxidase, reduced glutathione (GSH), and GSH/GSSG ratio were observed in both Alt and SL groups. Serum glutathione peroxidase and catalase did not change in SL, whereas these enzymes, respectively, decreased and increased in Alt. Uric acid (UA) decreased in SL and increased in Alt. Moreover, the decreases in GSH and GSH/GSSG ratio in Alt were relatively lower compared to those in SL. Further, significant interindividual correlations were found between changes in catalase and TBARS, as well as between UA and T-AOC. These findings suggest that long-term training at natural low altitude is unlikely to cause retained oxidative stress in professional adolescent runners. PMID:26783415

  11. A preliminary investigation into the relationship between functional movement screen scores and athletic physical performance in female team sport athletes.

    PubMed

    Lockie, Rg; Schultz, Ab; Callaghan, Sj; Jordan, Ca; Luczo, Tm; Jeffriess, Md

    2015-03-01

    There is little research investigating relationships between the Functional Movement Screen (FMS) and athletic performance in female athletes. This study analyzed the relationships between FMS (deep squat; hurdle step [HS]; in-line lunge [ILL]; shoulder mobility; active straight-leg raise [ASLR]; trunk stability push-up; rotary stability) scores, and performance tests (bilateral and unilateral sit-and-reach [flexibility]; 20-m sprint [linear speed]; 505 with turns from each leg; modified T-test with movement to left and right [change-of-direction speed]; bilateral and unilateral vertical and standing broad jumps; lateral jumps [leg power]). Nine healthy female recreational team sport athletes (age = 22.67 ± 5.12 years; height = 1.66 ± 0.05 m; body mass = 64.22 ± 4.44 kilograms) were screened in the FMS and completed the afore-mentioned tests. Percentage between-leg differences in unilateral sit-and-reach, 505 turns and the jumps, and difference between the T-test conditions, were also calculated. Spearman's correlations (p ≤ 0.05) examined relationships between the FMS and performance tests. Stepwise multiple regressions (p ≤ 0.05) were conducted for the performance tests to determine FMS predictors. Unilateral sit-and-reach positive correlated with the left-leg ASLR (r = 0.704-0.725). However, higher-scoring HS, ILL, and ASLR related to poorer 505 and T-test performance (r = 0.722-0.829). A higher-scored left-leg ASLR related to a poorer unilateral vertical and standing broad jump, which were the only significant relationships for jump performance. Predictive data tended to confirm the correlations. The results suggest limitations in using the FMS to identify movement deficiencies that could negatively impact athletic performance in female team sport athletes. PMID:25729149

  12. Association of the ACTN3 R577X Polymorphism in Polish Power-Orientated Athletes

    PubMed Central

    Cięszczyk, Paweł; Eider, Jerzy; Ostanek, Magdalena; Arczewska, Aleksandra; Leońska-Duniec, Agata; Sawczyn, Stanisław; Ficek, Krzysztof; Krupecki, Krzysztof

    2011-01-01

    Alpha-actinins are an ancient family of actin-binding proteins that play structural and regulatory roles in cytoskeletal organization. In skeletal muscle, α-actinin-3 protein is an important structural component of the Z disc, where it anchors actin thin filaments, helping to maintain the myofibrillar array. A common nonsense polymorphism in codon 577 of the ACTN3 gene (R577X) results in α-actinin-3 deficiency in XX homozygotes. Based on knowledge about the role of ACTN3 R557X polymorphism in skeletal muscle function, we postulated that the genetic polymorphism of ACTN3 could also improve sprint and power ability. We compared genotypic and allelic frequencies of the ACTN3 R557X polymorphism in two groups of men of the same Caucasian descent: 158 power-orientated athletes and 254 volunteers not involved in competitive sport. The genotype distribution in the group of power-oriented athletes showed significant differences (P=0.008) compared to controls. However, among the investigated subgroups of athletes, only the difference of ACTN3 R577X genotype between sprinters and controls reached statistical significance (P=0.041). The frequencies of the ACTN3 577X allele (30.69% vs. 40.35%; P=0.005) were significantly different in all athletes compared to controls. Our results support the hypothesis that the ACTN3 577XX allele may have some beneficial effect on sprint-power performance, because the ACTN3 XX genotype is significantly reduced in Polish power-oriented athletes compared to controls. This finding seems to be in agreement with previously reported case-control studies. However, ACTN3 polymorphism as a genetic marker for sport talent identification should be interpreted with great caution. PMID:23486986

  13. The use of ergogenic agents in high school athletes.

    PubMed

    Rosenfield, Charlene

    2005-12-01

    Statistics reporting adolescent use of ergogenic agents are staggering. According to the Centers for Disease Control and Prevention Youth Risk Behavior Surveillance, 6.1% of students from grades 9 through 12 had taken illegal anabolic steroids without a prescription one or more times during their lifetime. Additionally, more adolescent athletes are using non-Food and Drug Administration-regulated herbal supplements that claim ergogenic benefits. Many athletes either are unaware of or do not consider the possible health risks caused by these agents. School-based programs for athletes may be successful in preventing the use of ergogenic agents by increasing knowledge about such agents and offering skills in critical thinking to improve decision-making skills. PMID:16285842

  14. Sports Specialization and Intensive Training in Young Athletes.

    PubMed

    Brenner, Joel S

    2016-09-01

    Sports specialization is becoming the norm in youth sports for a variety of reasons. When sports specialization occurs too early, detrimental effects may occur, both physically and psychologically. If the timing is correct and sports specialization is performed under the correct conditions, the athlete may be successful in reaching specific goals. Young athletes who train intensively, whether specialized or not, can also be at risk of adverse effects on the mind and body. The purpose of this clinical report is to assist pediatricians in counseling their young athlete patients and their parents regarding sports specialization and intensive training. This report supports the American Academy of Pediatrics clinical report "Overuse Injuries, Overtraining, and Burnout in Child and Adolescent Athletes." PMID:27573090

  15. Appropriate and Inappropriate Practices for Coaching Female Athletes

    ERIC Educational Resources Information Center

    Bryan, Charity; Sims, Sandra

    2014-01-01

    This article is intended to provide coaches, parents/guardians and school administrators with specific guidelines that identify coaching practices that are in the best interests of the adolescent female athlete (appropriate) and those that are counterproductive or even harmful (inappropriate). These guidelines can be used as a self-assessment for…

  16. Caring for Student-Athletes following a Concussion

    ERIC Educational Resources Information Center

    Piebes, Sarah K.; Gourley, Meganne; Valovich McLeod, Tamara C.

    2009-01-01

    The school nurse plays a dynamic role in the care and treatment of a concussed athlete. Concussions in the adolescent populations are of special concern due to their potential impact on mental development and cognitive function, as well as an increased risk of serious complications including second impact syndrome. The complexity of a concussion…

  17. Helping Teenage Girls Avoid the Female Athlete Triad.

    ERIC Educational Resources Information Center

    Ilardi, Deb

    2002-01-01

    Describes how school nurses can advocate for adolescent female students and help them avoid the female athlete triad that includes disordered eating, amenorrhea, and osteoporosis. The article focuses on consequences of the triad, how to uncover the symptoms, working to improve public support, and creating a successful program through partnership.…

  18. Finances and College Athletics

    ERIC Educational Resources Information Center

    Hodge, Frank; Tanlu, Lloyd

    2009-01-01

    In 2008-2009, the National Collegiate Athletic Association (NCAA) generated television and marketing revenues of approximately $591 million, college sports apparel sales topped $4 billion, and several schools signed multimedia-rights deals for more than $100 million (Berkowitz, 2009; National Collegiate Athletic Association, 2009). At the Division…

  19. Female Athlete Triad

    MedlinePlus

    ... periods Learn more about healthy eating habits and healthy lifestyle choices Other Organizations Female Athlete Triad Coalition Questions to Ask Your Doctor ... female athlete triad? How do I strike a balance between my desire to be healthy and my desire to win? Could there be ...

  20. Athletic Director's Survival Guide.

    ERIC Educational Resources Information Center

    Koehler, Mike; Giebel, Nancy

    This book examines the duties assigned to athletic directors, offering successful strategies for achieving them and materials to make their jobs easier (e.g., sample memos, letters, forms, and charts for interacting successfully with coaches, students, administrators, and parents). Section 1 discusses the director's work with student athletes and…

  1. The Female Athlete Triad

    ERIC Educational Resources Information Center

    Sherman, Roberta Trattner; Thompson, Ron A.

    2004-01-01

    The Female Athlete Triad is a syndrome of the interrelated components of disordered eating, amenorrhea, and osteoporosis. Sometimes inadvertently, but more often by willful dietary restriction, many female athletes do not ingest sufficient calories to adequately fuel their physical or sport activities, which can disrupt menstrual functioning,…

  2. CAA: Computer Assisted Athletics.

    ERIC Educational Resources Information Center

    Hall, John H.

    Computers have been used in a variety of applications for athletics since the late 1950's. These have ranged from computer-controlled electric scoreboards to computer-designed pole vaulting poles. Described in this paper are a computer-based athletic injury reporting system and a computer-assisted football scouting system. The injury reporting…

  3. Salt, Water, and Athletes.

    ERIC Educational Resources Information Center

    Smith, Nathan J.

    Good nutrition for athletes demands plenty of water, since water is essential to such vital functions as muscle reactions. Dehydration can result from jet travel as well as from exercise and heat, making it a danger to traveling athletic teams. To avoid dehydration, water needs should be monitored by frequent weighing, and a clean water supply…

  4. Neuroendocrine mechanisms in athletes.

    PubMed

    Misra, Madhusmita

    2014-01-01

    Athletic activity may be associated with alterations in various neuroendocrine axes depending on the state of energy availability. In addition, genetic factors and an underlying predilection for polycystic ovarian syndrome (PCOS) may predispose some athletes to develop functional hypothalamic amenorrhea earlier than other athletes. In conditions of low energy availability associated with athletic activity, changes that occur in various neuroendocrine axes are primarily adaptive, and aim to either conserve energy for the most essential functions, or allow the body to draw on its reserves to meet energy needs. These hormonal changes, however, then lead to changes in body composition and bone metabolism. Impaired bone accrual in younger athletes and low bone density in older athletes constitutes the major pathologic consequence of neuroendocrine changes associated with low energy availability. The female athlete triad of low energy availability, menstrual dysfunction, and low bone density is prevalent in certain kinds of sports and activities, particularly endurance sports, gymnastics, and ballet. It is essential to screen for this condition in athletes at every preparticipation physical and during office visits, and to put in place an effective treatment team to manage the triad early, in order to optimize outcomes. PMID:25248600

  5. Athletic Liability: Managing Liability in Athletics and Physical Education.

    ERIC Educational Resources Information Center

    Association of School Business Officials International, Reston, VA.

    The trend toward more litigation and higher monetary awards in cases of injury of student athletes is a threat to school athletic programs. This document is a workshop aid for addressing legal issues surrounding student athletic activities, in particular, those involving the safety and health of student athletes, injury prevention, and preparation…

  6. National Athletic Trainers' Association Position Statement: Fluid Replacement for Athletes.

    ERIC Educational Resources Information Center

    Case, Douglas J.; Armstrong, Lawrence E.; Hillman, Susan K.; Montain, Scott J.; Reiff, Ralph V.; Rich, Brent S. E.; Roberts, William O.; Stone, Jennifer A.

    2000-01-01

    Presents recommendations from the National Athletic Trainers Association for optimizing the fluid replacement practices of athletes, explaining that dehydration can compromise athletic performance and increase the risk of exertional heat injury. Athletes must be educated about the risks of dehydration and overhydration. They must learn fluid…

  7. Performance Decrement and Skill Deterioration During a Water Polo Game are Linked With the Conditioning Level of the Athletes.

    PubMed

    Botonis, Petros G; Toubekis, Argyris G; Terzis, Gerasimos D; Geladas, Nickos D; Platanou, Theodoros I

    2016-04-01

    The aim of the study was to examine whether physical and technical performance deterioration after a water polo game is related to the athletes' conditioning level. Blood lactate concentration was measured during a 5 × 200-m incremental swimming test in 10 male water polo athletes to calculate the velocities corresponding to 4.0, 5.0, and 10.0 mmol·L lactate concentration (V4, V5, and V10, respectively) and define their conditioning level. All athletes participated in 5 competitive water polo games. Before (Pre), at half time (Mid), and after (Post) the first 2 games, handgrip strength and repeated sprint ability (8 × 20-m) were measured. Pre and Post the next 2 games, ball throwing velocity, shooting accuracy, and 400-m swim were evaluated. Pre, Mid, and Post the last game, the eggbeater kick test was performed. Handgrip strength, repeated sprint ability, 400-m swim performance, and ball shooting accuracy decreased after the game (8.4 ± 6.2%, 6.3 ± 3.4%, 7.0 ± 4.1%, and 20.3 ± 23.4%, respectively, p ≤ 0.05). V4, V5, and V10 were not significantly correlated with changes in physical or technical performance after the game. Performance in 400-m swim correlated with V4 and V5 whereas changes in 400-m swim Pre-Post, correlated with changes in ball shooting accuracy and throwing velocity (r = 0.73 and r = 0.80, p ≤ 0.05). These data suggest that V4, V5, and V10 may not correlate with performance decline in water polo. Interestingly, the 400-m swim test is connected with the decline in repeated sprints, ball shooting accuracy, and throwing velocity after a water polo game in well-trained athletes. PMID:26349048

  8. Agreement between High School Athletes and Their Parents on Reporting Athletic Events and Concussion Symptoms.

    PubMed

    Rowhani-Rahbar, Ali; Chrisman, Sara P D; Drescher, Sara; Schiff, Melissa A; Rivara, Frederick P

    2016-04-15

    An enhanced understanding of agreement levels between adolescents and parents for reporting athletic events and symptoms can help inform surveillance systems as well as clinical and epidemiological investigations of sports-related concussions. We sought to quantify agreement levels between high school athletes and parents for reporting: (1) number of games; (2) number of practices; (3) occurrence of an injury resulting in any concussion symptoms; and (4) presence of each specific symptom on the date of that injury among high school boys' football and girls' soccer athletes playing in Autumn 2012 in Washington State. There was substantial agreement on reporting the number of athletic events. Agreement levels were greater for games (kappa = 0.82; 95% confidence interval [CI]: 0.79-0.85 in boys' football; kappa = 0.75; 95% CI: 0.72-0.79 in girls' soccer) than for practices (kappa = 0.64; 95% CI: 0.62-0.67 in boys' football; kappa = 0.65; 95% CI: 0.62-0.67 in girls' soccer). There was moderate to substantial agreement on the occurrence of injury resulting in any concussion symptoms; however, agreement on the presence and severity of each symptom varied from poor to almost perfect. Overall, athletes reported greater severity of symptoms than parents did; notably, no difference in mean symptom scores was found when the athlete had a history of concussion. Agreement levels were greater when information was ascertained within 1 week of injury than when it was obtained later than 1 week. Including both athletes' and parents' reports of sports-related events and ascertaining information as soon as possible after injury are important considerations in designing injury surveillance systems. PMID:26414288

  9. Case Study: The Role of Milk in a Dietary Strategy to Increase Muscle Mass and Improve Recovery in an Elite Sprint Kayaker.

    PubMed

    Reid, Karen

    2016-04-01

    Flatwater kayaking requires upper-body muscle strength and a lean body composition. This case study describes a nutrition intervention with a 19-year-old male elite sprint kayaker to increase muscle mass and improve recovery posttraining. Before the intervention, average daily energy intake was 13.6 ± 2.5 MJ (M ± SD; protein, 1.8 g/kg; carbohydrate, 3.6 g/kg), and the athlete was unable to eat sufficient food to meet the energy demands of training. During the 18-month intervention period, the athlete’s daily energy intake increased to 22.1 ± 3.8 MJ (protein, 3.2 g/kg; carbohydrate, 7.7 g/kg) by including milk-based drinks pre- and posttraining and before bed and an additional carbohydrate-based snack midmorning. This simple dietary intervention, along with a structured strength and conditioning program, resulted in an increase of 10 kg body mass with minimal change in body fat percentage. Adequate vitamin D status was maintained without the need for supplementation during the intervention period. In addition, the athlete reported the milk-based drinks and carbohydrate snacks were easy to consume, and no adverse side effects were experienced. This was the first time the athlete was able to maintain weight during intensive phases of the training cycle. PMID:26480267

  10. The female athlete triad.

    PubMed

    Horn, Elizabeth; Gergen, Nicole; McGarry, Kelly A

    2014-11-01

    The female athlete triad is a spectrum of interrelated pathophysiologic consequences of low energy availability, menstrual dysfunction, and low bone mineral density. Components of the triad are not only counterproductive to athletic performance goals, but can lead to serious long-term negative health outcomes. Practitioners caring for female athletes play an important role detecting at-risk athletes early in their course along the disease spectrum. Importantly, women who are evaluated for one component of the triad should always be screened for the other two. Detecting the disorder early is the most important factor for preventing the potentially severe consequences, and requires heightened vigilance on the part of all those who work with this special patient population. In this article, we discuss the epidemiology, pathophysiology, diagnosis, evaluation, and management of the female athlete triad. PMID:25365814

  11. Female athlete triad update.

    PubMed

    Beals, Katherine A; Meyer, Nanna L

    2007-01-01

    The passage of Title IX legislation in 1972 provided enormous opportunities for women to reap the benefits of sports participation. For most female athletes, sports participation is a positive experience, providing improved physical fitness, enhanced self-esteem, and better physical and mental health. Nonetheless, for a few female athletes, the desire for athletic success combined with the pressure to achieve a prescribed body weight may lead to the development of a triad of medical disorders including disordered eating, menstrual dysfunction, and low bone mineral density (BMD)--known collectively as the female athlete triad. Alone or in combination, the disorders of the triad can have a negative impact on health and impair athletic performance. PMID:17241915

  12. SPRINT: The Systolic Processor with a Reconfigurable Interconnection Network of Transputers

    SciTech Connect

    De Groot, A.J.; Johansson, E.M.; Fitch, J.P.; Grant, C.W.; Parker, S.R.

    1987-05-01

    The Systolic Processor with a Reconfigurable Interconnection Network of Transputers (SPRINT) is a sixty-four-processor multiprocessor developed at Lawrence Livermore National Laboratory for experimentally evaluating systolic algorithms and architectures. This paper describes the architecture of the SPRINT and several algorithms which have been executed on it.

  13. The Effects of Psoas Major and Lumbar Lordosis on Hip Flexion and Sprint Performance

    ERIC Educational Resources Information Center

    Copaver, Karine; Hertogh, Claude; Hue, Olivier

    2012-01-01

    In this study, we analyzed the correlations between hip flexion power, sprint performance, lumbar lordosis (LL) and the cross-sectional area (CSA) of the psoas muscle (PM). Ten young adults performed two sprint tests and isokinetic tests to determine hip flexion power. Magnetic resonance imaging was used to determine LL and PM CSA. There were…

  14. A Comparison of Two Reading Fluency Methods: Repeated Readings to a Fluency Criterion and Interval Sprinting

    ERIC Educational Resources Information Center

    Kostewicz, Douglas E.; Kubina, Richard M., Jr.

    2010-01-01

    Teachers have used the method of repeated readings to build oral reading fluency in students with and without special needs. A new fluency building intervention called interval sprinting uses shorter timing intervals (i.e., sprints) across a passage. This study used an alternating treatment design to compare repeated readings and interval…

  15. Force-Time Characteristics and Running Velocity of Male Sprinters During the Acceleration Phase of Sprinting.

    ERIC Educational Resources Information Center

    Mero, Antti

    1988-01-01

    Investigation of the force-time characteristics of eight male sprinters during the acceleration phase of the sprint start suggested that the braking and propulsion phases occur immediately after the block phase and that muscle strength strongly affects running velocity in the sprint start. (Author/CB)

  16. Effect of a Cooling Vest on Core Temperature in Athletes With and Without Spinal Cord Injury

    PubMed Central

    Trbovich, Michelle

    2014-01-01

    Background: It is well accepted that persons with spinal cord injury (SCI) have impaired ability to regulate core temperature due to impaired vasomotor and sudomotor activity below their level of injury. Impaired heat dissipation puts SCI athletes at great risk of exercise-induced hyperthermia (EIH) (>37.8°C). There is minimal evidence for efficacy of any specific cooling method in SCI athletes in a thermoneutral sport-specific setting. Objective: To evaluate the extent of EIH in persons with and without SCI and subsequently examine the effect of a cooling vest to attenuate rise in core body temperature (Tc). Methods: SCI (n = 17) and able-bodied (AB; n = 19) athletes participated in a 60-minute intermittent sprinting exercise in a thermoneutral (21.1°C-23.9°C) environment. Participants were separated according to their level of injury: tetraplegia defined as above T1 (TP; n = 6), high paraplegia defined as T5 through T1 (HP; n = 5), low paraplegia defined as T6 and below (LP; n = 6), and AB (n = 19). Tc was recorded at 15-minute intervals using an ingestible thermometer pill. This protocol was completed with a cooling vest (V) and without a cooling vest (NV). Results: All SCI and most AB athletes experienced EIH. After 60 minutes, Tc of TP athletes was significantly increased compared to HP (P = .03) and AB athletes (P = .007). There was no significant effect of the vest on Tc over time for any group. Conclusions: TP athletes have the highest risk of exercise-induced hyperthermia. The cooling vest does not significantly attenuate rise in Tc in SCI or AB athletes. PMID:24574824

  17. Long-Term Outcomes of the ATHENA (Athletes Targeting Healthy Exercise & Nutrition Alternatives) Program for Female High School Athletes

    ERIC Educational Resources Information Center

    Elliot, Diane L.; Goldberg, Linn; Moe, Esther L.; DeFrancesco, Carol A.; Durham, Melissa B.; McGinnis, Wendy; Lockwood, Chondra

    2008-01-01

    Adolescence and emerging adulthood are critical windows for establishing life-long behaviors. We assessed long-term outcomes of a prospective randomized harm reduction/health promotion program for female high school athletes. The intervention's immediate beneficial effects on diet pill use and unhealthy eating behaviors have been reported;…

  18. Sonographic evaluation of athletic pubalgia.

    PubMed

    Morley, Nicholas; Grant, Thomas; Blount, Kevin; Omar, Imran

    2016-05-01

    Athletic pubalgia, or "sports hernia", represents a constellation of pathologic conditions occurring at and around the pubic symphysis. These injuries are primarily seen in athletes or those involved in athletic activity. In this article, we review the sonographic appearance of the relevant complex anatomy, scanning technique for ultrasound evaluation of athletic pubalgia, and the sonographic appearances of associated pathologic conditions. PMID:26861161

  19. Iron Deficiency in Adolescents and Young Adults.

    ERIC Educational Resources Information Center

    Risser, William L.; Risser, Jan M. H.

    1990-01-01

    Reviews the prevalence, natural history, causes, impact on performance, diagnosis, and treatment of iron deficiency in adolescent and young adult athletes. All athletes should be screened and treated. The best diagnosis involves determining serum ferritin and hemoglobin levels. Treatment requires therapeutic doses of oral ferrous iron for several…

  20. Systolic Blood Pressure Intervention Trial (SPRINT) and Target Systolic Blood Pressure in Future Hypertension Guidelines.

    PubMed

    Egan, Brent M; Li, Jiexiang; Wagner, C Shaun

    2016-08-01

    The Systolic Blood Pressure (SBP, mm Hg) Intervention Trial (SPRINT) showed that targeting SBP <120 mm Hg (intensive treatment, mean SBP: 121.5 mm Hg) versus <140 (standard treatment, mean SBP: 134.6 mm Hg) reduced cardiovascular events 25%. SPRINT has 2 implicit assumptions that could impact future US hypertension guidelines: (1) standard therapy controlled SBP similarly to that in adults with treated hypertension and (2) intensive therapy produced a lower mean SBP than in adults with treated hypertension and SBP <140 mm Hg. To examine these assumptions, US National Health and Nutrition Examination Survey 2009 to 2012 data were analyzed on 3 groups of adults with treated hypertension: group 1 consisted of SPRINT-like participants aged ≥50 years; group 2 consisted of participants all aged ≥18 years; and group 3 consisted of participants aged ≥18 years excluding group 1 but otherwise similar to SPRINT-like participants except high cardiovascular risk. Mean SBPs in groups 1, 2, and 3 were 133.0, 130.1, and 124.6, with 66.2%, 72.2%, and 81.9%, respectively, controlled to SBP <140; 68.3%, 74.8%, and 83.4% of the controlled subset had SBP <130. Mean SBPs in those controlled to <140 were 123.3, 120.9, and 118.9, respectively. Among US adults with treated hypertension, (1) the SPRINT-like group had higher mean SBP than comparison groups, yet lower than SPRINT standard treatment group and (2) among groups 1 to 3 with SBP <140, SBP values were within <3 mm Hg of SPRINT intensive treatment. SPRINT results suggest that treatment should be continued and not reduced when treated SBP is <130, especially for the SPRINT-like subset. Furthermore, increasing the percentage of treated adults with SBP <140 could approximate SPRINT intensive treatment SBP without lowering treatment goals. PMID:27354422

  1. Neck-cooling improves repeated sprint performance in the heat

    PubMed Central

    Sunderland, Caroline; Stevens, Ryan; Everson, Bethan; Tyler, Christopher J.

    2015-01-01

    The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 × 6 s) before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0 ± 0.2°C; 53 ± 2% relative humidity). Participants wore a neck-cooling collar in one of the trials (CC). Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122 W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively). The improved power output was particularly pronounced (d = 0.51–0.88) after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P < 0.001) but had no effect on heart rate, fluid loss, fluid consumption, lactate, glucose, plasma volume change, cortisol, or thermal sensation (P > 0.05). There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE). Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 min onwards (interaction trial × time P = 0.04). RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial × time P = 0.01). Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement. PMID:26594177

  2. Exploiting Parallel R in the Cloud with SPRINT

    PubMed Central

    Piotrowski, M.; McGilvary, G.A.; Sloan, T. M.; Mewissen, M.; Lloyd, A.D.; Forster, T.; Mitchell, L.; Ghazal, P.; Hill, J.

    2012-01-01

    Background Advances in DNA Microarray devices and next-generation massively parallel DNA sequencing platforms have led to an exponential growth in data availability but the arising opportunities require adequate computing resources. High Performance Computing (HPC) in the Cloud offers an affordable way of meeting this need. Objectives Bioconductor, a popular tool for high-throughput genomic data analysis, is distributed as add-on modules for the R statistical programming language but R has no native capabilities for exploiting multi-processor architectures. SPRINT is an R package that enables easy access to HPC for genomics researchers. This paper investigates: setting up and running SPRINT-enabled genomic analyses on Amazon’s Elastic Compute Cloud (EC2), the advantages of submitting applications to EC2 from different parts of the world and, if resource underutilization can improve application performance. Methods The SPRINT parallel implementations of correlation, permutation testing, partitioning around medoids and the multi-purpose papply have been benchmarked on data sets of various size on Amazon EC2. Jobs have been submitted from both the UK and Thailand to investigate monetary differences. Results It is possible to obtain good, scalable performance but the level of improvement is dependent upon the nature of algorithm. Resource underutilization can further improve the time to result. End-user’s location impacts on costs due to factors such as local taxation. Conclusions: Although not designed to satisfy HPC requirements, Amazon EC2 and cloud computing in general provides an interesting alternative and provides new possibilities for smaller organisations with limited funds. PMID:23223611

  3. Sprint, agility, strength and endurance capacity in wheelchair basketball players

    PubMed Central

    Granados, C; Otero, M; Badiola, A; Olasagasti, J; Bidaurrazaga-Letona, I; Iturricastillo, A; Gil, SM

    2014-01-01

    The aims of the present study were, firstly, to determine the reliability and reproducibility of an agility T-test and Yo-Yo 10 m recovery test; and secondly, to analyse the physical characteristics measured by sprint, agility, strength and endurance field tests in wheelchair basketball (WB) players. 16 WB players (33.06 ± 7.36 years, 71.89 ± 21.71 kg and sitting body height 86.07 ± 6.82 cm) belonging to the national WB league participated in this study. Wheelchair sprint (5 and 20 m without ball, and 5 and 20 m with ball) agility (T-test and pick-up test) strength (handgrip and maximal pass) and endurance (Yo-Yo 10 m recovery test) were performed. T-test and Yo-Yo 10 m recovery test showed good reproducibility values (intraclass correlation coefficient, ICC = 0.74-0.94). The WB players’ results in 5 and 20 m sprints without a ball were 1.87 ± 0.21 s and 5.70 ± 0.43 s and with a ball 2.10 ± 0.30 s and 6.59 ± 0.61 s, being better than those reported in the literature. Regarding the pick-up test results (16.05 ± 0.52 s) and maximal pass (8.39 ± 1.77 m), players showed worse values than those obtained in elite players. The main contribution of the present study is the characterization of the physical performance profile of WB players using a field test battery. Furthermore, we demonstrated that the agility T-test and the aerobic Yo-Yo 10 m recovery test are reliable; consequently they may be appropriate instruments for measuring physical fitness in WB. PMID:25729153

  4. Neck-cooling improves repeated sprint performance in the heat.

    PubMed

    Sunderland, Caroline; Stevens, Ryan; Everson, Bethan; Tyler, Christopher J

    2015-01-01

    The present study evaluated the effect of neck-cooling during exercise on repeated sprint ability in a hot environment. Seven team-sport playing males completed two experimental trials involving repeated sprint exercise (5 × 6 s) before and after two 45 min bouts of a football specific intermittent treadmill protocol in the heat (33.0 ± 0.2°C; 53 ± 2% relative humidity). Participants wore a neck-cooling collar in one of the trials (CC). Mean power output and peak power output declined over time in both trials but were higher in CC (540 ± 99 v 507 ± 122 W, d = 0.32; 719 ± 158 v 680 ± 182 W, d = 0.24 respectively). The improved power output was particularly pronounced (d = 0.51-0.88) after the 2nd 45 min bout but the CC had no effect on % fatigue. The collar lowered neck temperature and the thermal sensation of the neck (P < 0.001) but had no effect on heart rate, fluid loss, fluid consumption, lactate, glucose, plasma volume change, cortisol, or thermal sensation (P > 0.05). There were no trial differences but interaction effects were demonstrated for prolactin concentration and rating of perceived exertion (RPE). Prolactin concentration was initially higher in the collar cold trial and then was lower from 45 min onwards (interaction trial × time P = 0.04). RPE was lower during the football intermittent treadmill protocol in the collar cold trial (interaction trial × time P = 0.01). Neck-cooling during exercise improves repeated sprint performance in a hot environment without altering physiological or neuroendocrinological responses. RPE is reduced and may partially explain the performance improvement. PMID:26594177

  5. Athletic osteitis pubis.

    PubMed

    Hiti, Corey J; Stevens, Kathryn J; Jamati, Moira K; Garza, Daniel; Matheson, Gordon O

    2011-05-01

    Athletic osteitis pubis is a painful and chronic condition affecting the pubic symphysis and/or parasymphyseal bone that develops after athletic activity. Athletes with osteitis pubis commonly present with anterior and medial groin pain and, in some cases, may have pain centred directly over the pubic symphysis. Pain may also be felt in the adductor region, lower abdominal muscles, perineal region, inguinal region or scrotum. The pain is usually aggravated by running, cutting, hip adduction and flexion against resistance, and loading of the rectus abdominis. The pain can progress such that athletes are unable to sustain athletic activity at high levels. It is postulated that osteitis pubis is an overuse injury caused by biomechanical overloading of the pubic symphysis and adjacent parasymphyseal bone with subsequent bony stress reaction. The differential diagnosis for osteitis pubis is extensive and includes many other syndromes resulting in groin pain. Imaging, particularly in the form of MRI, may be helpful in making the diagnosis. Treatment is variable, but typically begins with conservative measures and may include injections and/or surgical procedures. Prolotherapy injections of dextrose, anti-inflammatory corticosteroids and a variety of surgical procedures have been reported in the literature with varying efficacies. Future studies of athletic osteitis pubis should attempt to define specific and reliable criteria to make the diagnosis of athletic osteitis pubis, empirically define standards of care and reduce the variability of proposed treatment regimens. PMID:21510714

  6. Athletic pubalgia (sports hernia).

    PubMed

    Litwin, Demetrius E M; Sneider, Erica B; McEnaney, Patrick M; Busconi, Brian D

    2011-04-01

    Athletic pubalgia or sports hernia is a syndrome of chronic lower abdomen and groin pain that may occur in athletes and nonathletes. Because the differential diagnosis of chronic lower abdomen and groin pain is so broad, only a small number of patients with chronic lower abdomen and groin pain fulfill the diagnostic criteria of athletic pubalgia (sports hernia). The literature published to date regarding the cause, pathogenesis, diagnosis, and treatment of sports hernias is confusing. This article summarizes the current information and our present approach to this chronic lower abdomen and groin pain syndrome. PMID:21419964

  7. Photobiomodulation in athletic training

    NASA Astrophysics Data System (ADS)

    Liu, Timon Cheng-Yi; Liu, Jiang; Wang, Shuang-Xi; Cui, Li-Ping; Xu, Xiao-Yang; Lu, Jian; Deng, Xiao-Yuan; Liu, Song-Hao

    2006-09-01

    Photobiomodulation (PBM) has been mainly used in athlete trauma care. In this paper, the possible applications of PBM in athlete medical care to maintain pro-oxidant-antioxidant homeostasis and in athlete trauma care to treat osteoarthritis and delayed onset of muscular soreness (DOMS) have been discussed. In order to maintain pro-oxidant-antioxidant homeostasis, PBM might be used in an intravascular way, in an endonasal way or in a directly irradiated way. DOMS was supposed to have three phases, z-line disruption, proteolysis of damaged proteins and protein synthesis for myofibril remodeling, each of which might have its own optimum dose of PBM.

  8. Effects of additional repeated sprint training during preseason on performance, heart rate variability, and stress symptoms in futsal players: a randomized controlled trial.

    PubMed

    Soares-Caldeira, Lúcio F; de Souza, Eberton A; de Freitas, Victor H; de Moraes, Solange M F; Leicht, Anthony S; Nakamura, Fábio Y

    2014-10-01

    The aim of this study was to investigate whether supplementing regular preseason futsal training with weekly sessions of repeated sprints (RS) training would have positive effects on repeated sprint ability (RSA) and field test performance. Thirteen players from a professional futsal team (22.6 ± 6.7 years, 72.8 ± 8.7 kg, 173.2 ± 6.2 cm) were divided randomly into 2 groups (AddT: n = 6 and normal training group: n = 7). Both groups performed a RSA test, Yo-Yo intermittent recovery test level 1 (YoYo IR1), squat (SJ) and countermovement jumps (CMJ), body composition, and heart rate variability (HRV) measures at rest before and after 4 weeks of preseason training. Athletes weekly stress symptoms were recorded by psychometric responses using the Daily Analysis of Life Demands for Athletes questionnaire and subjective ratings of well-being scale, respectively. The daily training load (arbitrary units) was assessed using the session of rating perceived exertion method. After the preseason training, there were no significant changes for body composition, SJ, CMJ, and RSAbest. The YoYo IR1, RSAmean, RSAworst, and RSAdecreament were significantly improved for both groups (p ≤ 0.05). The HRV parameters improved significantly within both groups (p ≤ 0.05) except for high frequency (HF, absolute and normalized units, [n.u.]), low frequency (LF) (n.u.), and the LF/HF ratio. A moderate effect size for the AddT group was observed for resting heart rate and several HRV measures. Training load and psychometric responses were similar between both groups. Additional RS training resulted in slightly greater positive changes for vagal-related HRV with similar improvements in performance and training stress during the preseason training in futsal players. PMID:24662230

  9. Performance changes and relationship between vertical jump measures and actual sprint performance in elite sprinters with visual impairment throughout a Parapan American games training season

    PubMed Central

    Loturco, Irineu; Winckler, Ciro; Kobal, Ronaldo; Cal Abad, Cesar C.; Kitamura, Katia; Veríssimo, Amaury W.; Pereira, Lucas A.; Nakamura, Fábio Y.

    2015-01-01

    The aims of this study were to estimate the magnitude of variability and progression in actual competitive and field vertical jump test performances in elite Paralympic sprinters with visual impairment in the year leading up to the 2015 Parapan American Games, and to investigate the relationships between loaded and unloaded vertical jumping test results and actual competitive sprinting performance. Fifteen Brazilian Paralympic sprinters with visual impairment attended seven official competitions (four national, two international and the Parapan American Games 2015) between April 2014 and August 2015, in the 100- and 200-m dash. In addition, they were tested in five different periods using loaded (mean propulsive power [MPP] in jump squat [JS] exercise) and unloaded (squat jump [SJ] height) vertical jumps within the 3 weeks immediately prior to the main competitions. The smallest important effect on performances was calculated as half of the within-athlete race-to-race (or test-to-test) variability and a multiple regression analysis was performed to predict the 100- and 200-m dash performances using the vertical jump test results. Competitive performance was enhanced during the Parapan American Games in comparison to the previous competition averages, overcoming the smallest worthwhile enhancement in both the 100- (0.9%) and 200-m dash (1.43%). In addition, The SJ and JS explained 66% of the performance variance in the competitive results. This study showed that vertical jump tests, in loaded and unloaded conditions, could be good predictors of the athletes' sprinting performance, and that during the Parapan American Games the Brazilian team reached its peak competitive performance. PMID:26594181

  10. Inspiratory muscle fatigue affects latissimus dorsi but not pectoralis major activity during arms only front crawl sprinting.

    PubMed

    Lomax, Mitch; Tasker, Louise; Bostanci, Ozgur

    2014-08-01

    The purpose of this study was to determine whether inspiratory muscle fatigue (IMF) affects the muscle activity of the latissimus dorsi and pectoralis major during maximal arms only front crawl swimming. Eight collegiate swimmers were recruited to perform 2 maximal 20-second arms only front crawl sprints in a swimming flume. Both sprints were performed on the same day, and IMF was induced 30 minutes after the first (control) sprint. Maximal inspiratory and expiratory mouth pressures (PImax and PEmax, respectively) were measured before and after each sprint. The median frequency (MDF) of the electromyographic signal burst was recorded from the latissimus dorsi and pectoralis major during each 20-second sprint along with stroke rate and breathing frequency. Median frequency was assessed in absolute units (Hz) and then referenced to the start of the control sprint for normalization. After IMF inducement, stroke rate increased from 56 ± 4 to 59 ± 5 cycles per minute, and latissimus dorsi MDF fell from 67 ± 11 Hz at the start of the sprint to 61 ± 9 Hz at the end. No change was observed in the MDF of the latissimus dorsi during the control sprint. Conversely, the MDF of the pectoralis major shifted to lower frequencies during both sprints but was unaffected by IMF. As the latter induced fatigue in the latissimus dorsi, which was not otherwise apparent during maximal arms only control sprinting, the presence of IMF affects the activity of the latissimus dorsi during front crawl sprinting. PMID:24402450

  11. Body Composition, Hemodynamic and Biochemical Parameters in Young Female Normal-Weight Oligo-amenorrheic and Eumenorrheic Athletes and Non-athletes

    PubMed Central

    Singhal, Vibha; de Lourdes Eguiguren, Maria; Eysenbach, Lindsey; Clarke, Hannah; Slattery, Meghan; Eddy, Kamryn; Ackerman, Kathryn E.; Misra, Madhusmita

    2014-01-01

    Aims Low-weight hypogonadal conditions such as anorexia nervosa are associated with marked changes in body composition, hemodynamic and hematological parameters, and liver enzymes. The impact of athletic activity in normal-weight adolescents with/without amenorrhea on these parameters has not been assessed. Our aim was to examine these parameters in normal-weight athletes and non-athletes and determine any associations of body composition, oligo-amenorrhea and exercise intensity. Methods We assessed vital signs, complete blood counts, liver enzymes, and regional body composition in 43 oligo-amenorrheic athletes (OAA), 24 eumenorrheic athletes (EA) and 23 non-athletes 14-21 years of age. Results BMI was lower in OAA than EA. Systolic and pulse pressure, and temperature were lowest in OAA. Blood counts did not differ among groups. AST was higher in both groups of athletes, while ALT was higher in OAA than EA and non-athletes. Total and regional fat was lower in OAA than other groups, positively associated with heart rate and inversely with liver enzymes. Conclusions Athletic activity is associated with higher AST, whereas menstrual dysfunction is associated with lower total and regional fat and higher ALT. Higher liver enzymes are associated with reductions in total and regional fat. PMID:25376841

  12. Paths to expertise in portuguese national team athletes.

    PubMed

    Leite, Nuno; Baker, Joseph; Sampaio, Jaime

    2009-01-01

    The purpose of this study was to identify the quantity and type of sporting activities undertaken by expert team sport athletes in the earlier stages of the long- term athlete development. Experts in roller-hockey (n = 19), volleyball (n = 14), soccer (n = 42) and basketball (n = 37) provided detailed information about the sporting activities they undertook throughout their careers. Results showed considerable variation between and within sports; however, generally, athletes began participating in sports between 6 and 10 years of age. The pattern of participation in specific and non-specific (team, individual and combat) sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. Our results suggest that involvement in multiple sports during early stages of development is an alternative to early specialization and add further evidence of the complexity of skill acquisition in sport. Key pointsAlthough most athletes began sport participation between 6 and 10 years of age, there was significant variation across groups suggesting considerable flexibility in the pathways to expertise.The path to expertise in volleyball was clearly distinct from the paths of basketball, soccer and roller-hockey.There is a considerable involvement in sports other than the athlete's primary sport, suggesting early specialization is not required for these sports.The pattern of participation in specific and non-specific sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. PMID:24149598

  13. Nerve Injuries in Athletes.

    ERIC Educational Resources Information Center

    Collins, Kathryn; And Others

    1988-01-01

    Over a two-year period this study evaluated the condition of 65 athletes with nerve injuries. These injuries represent the spectrum of nerve injuries likely to be encountered in sports medicine clinics. (Author/MT)

  14. Jet Lag in Athletes

    PubMed Central

    Lee, Aaron; Galvez, Juan Carlos

    2012-01-01

    Context: Prolonged transmeridian air travel can impart a physical and emotional burden on athletes in jet lag and travel fatigue. Jet lag may negatively affect the performance of athletes. Study Type: Descriptive review. Evidence Acquisition: A Medline search for articles relating to jet lag was performed (1990-present), as was a search relating to jet lag and athletes (1983-January, 2012). The results were reviewed for relevance. Eighty-nine sources were included in this descriptive review. Results: Behavioral strategies are recommended over pharmacological strategies when traveling with athletes; pharmacological aides may be used on an individual basis. Strategic sleeping, timed exposure to bright light, and the use of melatonin are encouraged. Conclusions: There is strong evidence that mood and cognition are adversely affected by jet lag. Some measures of individual and team performance are adversely affected as well. PMID:23016089

  15. Biomechanically Engineered Athletes.

    ERIC Educational Resources Information Center

    Perry, Tekla S.

    1991-01-01

    The real-world meeting of electronics, computer monitoring, control systems, and mathematics, introduced in the context of sports, is described. Recent advances in the field of biomechanics and its use in improving athletic performance are discussed. (KR)

  16. Cardiac Imaging In Athletes

    PubMed Central

    Khan, Asaad A.; Safi, Lucy; Wood, Malissa

    2016-01-01

    Athletic heart syndrome refers to the physiological and morphological changes that occur in a human heart after repetitive strenuous physical exercise. Examples of exercise-induced changes in the heart include increases in heart cavity dimensions, augmentation of cardiac output, and increases in heart muscle mass. These cardiac adaptations vary based on the type of exercise performed and are often referred to as sport-specific cardiac remodeling. The hemodynamic effects of endurance and strength training exercise lead to these adaptations. Any abnormalities in chamber dilatation and left ventricular function usually normalize with cessation of exercise. Athletic heart syndrome is rare and should be differentiated from pathologic conditions such as hypertrophic cardiomyopathy, left ventricular noncompaction, and arrhythmogenic right ventricular dysplasia when assessing a patient for athletic heart syndrome. This paper describes specific adaptations that occur in athletic heart syndrome and tools to distinguish between healthy alterations versus underlying pathology. PMID:27486490

  17. Living at high altitude in combination with sea-level sprint training increases hematological parameters but does not improve performance in rats.

    PubMed

    Martinez-Bello, Vladimir Essau; Sanchis-Gomar, Fabian; Nascimento, Ana Lucia; Pallardo, Federico V; Ibañez-Sania, Sandra; Olaso-Gonzalez, Gloria; Calbet, Jose Antonio; Gomez-Cabrera, Mari Carmen; Viña, Jose

    2011-06-01

    The regimen of aerobic training at sea level with recovery at high altitude has been used by athletes to improve performance. However, little is known about the effects of hypoxia when combined with sprint interval training on performance. The aim of the present study was to determine the effect of a "living high-sprint training low" strategy on hemoglobin, hematocrit and erythropoietin levels in rats. We also wanted to test whether the addition of a hypoxic stress to the program of daily treadmill running at high speeds induces expressional adaptations in skeletal muscle and affects performance. The protein content of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α), cytochrome C, pyruvate dehydrogenase kinase (PDK1), heat shock protein 70 (HSP70), manganese superoxide dismutase (MnSOD) and citrate synthase activity were determined in different muscle fiber types in our animals (red and white gastrocnemius muscle). We also determined the maximal aerobic velocity (MAV) before and after the training period. A total of 24 male Wistar rats (3 month old) were randomly divided into four experimental groups: the normoxic control group (n = 6), the normoxic trained group (n = 6), the hypoxic control group (12 h pO(2) 12%/12 h pO(2) 21%) (n = 6) and the hypoxic trained group (12 h pO(2) 12%/12 h pO(2) 21%). Living in normobaric hypoxia condition for 21 days significantly increased hemoglobin, hematocrit and erythropoietin levels in both the rest and the trained groups. The trained animals (normoxia and hypoxia) significantly increased their maximal aerobic velocity. No changes were found in the skeletal muscle in PGC-1α, cytochrome C, PDK1, HSP70, MnSOD protein content and in the citrate synthase activity in any experimental group. Regardless of whether it is combined with sprint interval training or not, after 21 days of living at high altitude we found a significant increase in the hematological values determined in our study. However, contrary to

  18. Genes and athletes.

    PubMed

    Patel, Dilip R; Greydanus, Donald E

    2002-06-01

    Genetics plays an important role in determining characteristics desired for success in a given sport. Advances in biotechnology pose interesting and perplexing dilemmas for athletes, parents, health care providers, and society at large. Gene therapy holds great prospects for disease prevention and treatment. The same techniques also can be misused for genetic manipulation to enhance athletic prowess. This chapter reviews selective aspects of genotype influence on sport performance, uses and misuses of genetic technology, and ethical as well as legal dilemmas. PMID:11986034

  19. Human ankle plantar flexor muscle-tendon mechanics and energetics during maximum acceleration sprinting.

    PubMed

    Lai, Adrian; Schache, Anthony G; Brown, Nicholas A T; Pandy, Marcus G

    2016-08-01

    Tendon elastic strain energy is the dominant contributor to muscle-tendon work during steady-state running. Does this behaviour also occur for sprint accelerations? We used experimental data and computational modelling to quantify muscle fascicle work and tendon elastic strain energy for the human ankle plantar flexors (specifically soleus and medial gastrocnemius) for multiple foot contacts of a maximal sprint as well as for running at a steady-state speed. Positive work done by the soleus and medial gastrocnemius muscle fascicles decreased incrementally throughout the maximal sprint and both muscles performed more work for the first foot contact of the maximal sprint (FC1) compared with steady-state running at 5 m s(-1) (SS5). However, the differences in tendon strain energy for both muscles were negligible throughout the maximal sprint and when comparing FC1 to SS5. Consequently, the contribution of muscle fascicle work to stored tendon elastic strain energy was greater for FC1 compared with subsequent foot contacts of the maximal sprint and compared with SS5. We conclude that tendon elastic strain energy in the ankle plantar flexors is just as vital at the start of a maximal sprint as it is at the end, and as it is for running at a constant speed. PMID:27581481

  20. Importance of Muscle Power Variables in Repeated and Single Sprint Performance in Soccer Players

    PubMed Central

    López-Segovia, Manuel; Dellal, Alexandre; Chamari, Karim; González-Badillo, Juan José

    2014-01-01

    This study examined the relationship between lower body power and repeated as well as single sprint performance in soccer players. The performance of nineteen male soccer players was examined. The first testing session included the countermovement jump (CMJL) and the progressive full squat (FSL), both with external loads. Power in the CMJL and FSL was measured with each load that was lifted. The second session included a protocol of 40-m repeated sprints with a long recovery period (2 min). The number of sprints executed until there was a 3% decrease in performance for the best 40-m sprint time was recorded as a repeated sprint index (RSI). The RSI was moderately associated with power output relative to body mass in the CMJL and FSL (r = 0.53/0.54, p ≤ 0.05). The most and least powerful players (determined by FSL) showed significant differences in the RSI (9.1 ± 4.2 vs. 6.5 ± 1.6) and 10 m sprint time (p ± 0.01). Repeated and single sprints are associated with relatively lower body power in soccer players. PMID:25031688

  1. Asthma in elite athletes.

    PubMed

    Elers, Jimmi; Pedersen, Lars; Backer, Vibeke

    2011-06-01

    Asthma is frequently found among elite athletes performing endurance sports such as swimming, rowing and cross-country skiing. Although these athletes often report symptoms while exercising, they seldom have symptoms at rest. Moreover, compared with nonathletic asthmatic individuals, elite athletes have been shown to have a different distribution of airway inflammation and unequal response to bronchial provocative test. Elite athletes display signs of exercise-induced symptoms, for example, nonasthmatic inspiratory wheeze, vocal cord dysfunction and cardiac arrhythmias, which could limit their physical capacity. Elite athletes should undergo comprehensive assessment to confirm an asthma diagnosis and determine its degree of severity. Treatment should be as for any other asthmatic individual, including the use of β2-agonist, inhaled steroid as well as leukotriene-antagonist. It should, however, be noted that daily use of β-agonists could expose elite athletes to the risk of developing tolerance towards these drugs. Use of β2-agonist should be replaced with daily inhaled corticosteroid treatment, the most important treatment of exercise-induced asthma. All physicians treating asthma should be aware of the doping aspects. Systemic β2-agonist intake is strictly prohibited, whereas inhaled treatment is allowed in therapeutic doses when asthma is documented and dispensation has been granted when needed. PMID:21702657

  2. Dietary regimens of athletes competing at the Delhi 2010 Commonwealth Games.

    PubMed

    Pelly, Fiona E; Burkhart, Sarah J

    2014-02-01

    The aim of this study was to investigate the dietary regimens reported by athletes competing at a major international competition and report whether these were based on nutrient composition, religious beliefs, cultural eating style, food intolerance or avoidance of certain ingredients. A questionnaire was randomly distributed to 351 athletes in the main dining hall of the athletes' village over the three main meal periods during the Delhi 2010 Commonwealth Games (23rd Sept-14th Oct, 2010). The majority (n = 218, 62%) of athletes reported following one or more dietary regimens, with 50% (n = 174) following a diet based on the nutrient composition of the food. Significantly more athletes from weight category and aesthetic sports (28%, p = .005) and from power/sprint sports (41%, p = .004) followed low fat and high protein regimens respectively. Other specialized dietary regimens were followed by 33% of participants, with avoidance of red meat (13%), vegetarian (7%), Halal (6%), and low lactose regimens (5%) reported most frequently. Significantly more athletes from non-Western regions followed a vegetarian diet (p < .001), while more vegetarians reported avoiding additives (p = .013) and wheat (p ≤ .001). A Western style of eating was the most commonly reported cultural regimen (72% of total with 23% from non-Western regions). Those following a Western diet were significantly more likely to report following a regimen based on nutrient composition (p = .02). As a high proportion of athletes from differing countries and sports follow specialized dietary regimens, caterers and organizers should ensure that adequate nutrition support and food items are available at similar events. PMID:23918635

  3. Running mechanical alterations during repeated treadmill sprints in hot versus hypoxic environments. A pilot study.

    PubMed

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P

    2016-01-01

    We determined if performance and mechanical running alterations during repeated treadmill sprinting differ between severely hot and hypoxic environments. Six male recreational sportsmen (team- and racket-sport background) performed five 5-s sprints with 25-s recovery on an instrumented treadmill, allowing the continuous (step-by-step) measurement of running kinetics/kinematics and spring-mass characteristics. These were randomly conducted in control (CON; 25°C/45% RH, inspired fraction of oxygen = 20.9%), hot (HOT; 38°C/21% RH, inspired fraction of oxygen = 20.9%; end-exercise core temperature: ~38.6°C) and normobaric hypoxic (HYP, 25°C/45% RH, inspired fraction of oxygen = 13.3%/simulated altitude of ~3600 m; end-exercise pulse oxygen saturation: ~84%) environments. Running distance was lower (P < 0.05) in HOT compared to CON and HYP for the first sprint but larger (P < 0.05) sprint decrement score occurred in HYP versus HOT and CON. Compared to CON, the cumulated distance covered over the five sprints was lower (P < 0.01) in HYP but not in HOT. Irrespective of the environmental condition, significant changes occurred from the first to the fifth sprint repetitions (all three conditions compounded) in selected running kinetics (mean horizontal forces, P < 0.01) or kinematics (contact and swing times, both P < 0.001; step frequency, P < 0.001) and spring-mass characteristics (vertical stiffness, P < 0.001; leg stiffness, P < 0.01). No significant interaction between sprint number and condition was found for any mechanical data. Preliminary evidence indicates that repeated-sprint ability is more impaired in hypoxia than in a hot environment, when compared to a control condition. However, as sprints are repeated, mechanical alterations appear not to be exacerbated in severe (heat, hypoxia) environmental conditions. PMID:26473996

  4. The relationships among sprint performance, voluntary swimming activity, and social dominance in juvenile rainbow trout.

    PubMed

    McDonald, D G; Keeler, R A; McFarlane, W J

    2007-01-01

    The specific objectives of this study were to determine whether sprint performance in juvenile rainbow trout is correlated with either voluntary swimming activity or aggressive behaviors and to determine the reciprocal: the effect of swimming activity and aggression on sprint performance. Sprint performance was assessed by rapidly accelerating trout (5-7-cm fork length) to a fixed velocity (40, 42, or 45 cm s(-1)) and then holding them at that velocity until fatigue. There was considerable interindividual variation in sprint performance not explained by variations in body size, but intraindividual performance was highly repeatable over at least 2 mo. Voluntary swimming was measured as the frequency of transits (voluntary transit activity, VTA) between two identical tanks via a connecting channel with two different flow regimes: zero or minimum velocity (0 or 2.5 cm s(-1)) and high velocity (84 cm s(-1)). There was a strong correlation between sprint performance and VTA in minimal current but no correlation in high current. Furthermore, sprint performance did not predict the outcome of dominance encounters. Experience with rapid acceleration, especially when voluntary, led to a pronounced improvement in sprint performance in proportion to the number of acceleration events. Social dominance encounters had a more complex effect: a significant reduction in sprint performance in previously high-performance sprinters and the reverse for low performers. We propose that there are four independent axes of interindividual variation in juvenile rainbow trout: spontaneous and rheotaxis-stimulated locomotor activity, aggressive activity, and the trainability of sprint performance. The independence of these axes has the potential to produce a much larger diversity in behavioral and ultimately physiological phenotypes than would be produced if the axes were linked. PMID:17909998

  5. Neuromuscular and athletic performance following core strength training in elite youth soccer: Role of instability.

    PubMed

    Prieske, O; Muehlbauer, T; Borde, R; Gube, M; Bruhn, S; Behm, D G; Granacher, U

    2016-01-01

    Cross-sectional studies revealed that inclusion of unstable elements in core-strengthening exercises produced increases in trunk muscle activity and thus potential extra stimuli to induce more pronounced performance enhancements in youth athletes. Thus, the purpose of the study was to investigate changes in neuromuscular and athletic performance following core strength training performed on unstable (CSTU) compared with stable surfaces (CSTS) in youth soccer players. Thirty-nine male elite soccer players (age: 17 ± 1 years) were assigned to two groups performing a progressive core strength-training program for 9 weeks (2-3 times/week) in addition to regular in-season soccer training. CSTS group conducted core exercises on stable (i.e., floor, bench) and CSTU group on unstable (e.g., Thera-Band® Stability Trainer, Togu© Swiss ball) surfaces. Measurements included tests for assessing trunk muscle strength/activation, countermovement jump height, sprint time, agility time, and kicking performance. Statistical analysis revealed significant main effects of test (pre vs post) for trunk extensor strength (5%, P < 0.05, d = 0.86), 10-20-m sprint time (3%, P < 0.05, d = 2.56), and kicking performance (1%, P < 0.01, d = 1.28). No significant Group × test interactions were observed for any variable. In conclusion, trunk muscle strength, sprint, and kicking performance improved following CSTU and CSTS when conducted in combination with regular soccer training. PMID:25559249

  6. The Skeletally Immature and Newly Mature Throwing Athlete.

    PubMed

    Braithwaite, Kiery A; Marshall, Kelley W

    2016-09-01

    Injuries to the shoulder and elbow in the pediatric and adolescent throwing athlete are common. Both knowledge of throwing mechanics and understanding of normal bone development in the immature skeleton are key to the diagnosis, treatment, and potential prevention of these common injuries. Pathologic changes from chronic repetitive trauma to the developing shoulder and elbow manifest as distinctly different injuries that can be predicted by the skeletal maturation of the patient. Sites of vulnerability and resulting patterns of injury change as the child evolves from the skeletally immature little league player to the skeletally mature high school/college athlete. PMID:27545423

  7. Athletic Performance at the National Basketball Association Combine After Anterior Cruciate Ligament Reconstruction

    PubMed Central

    Mehran, Nima; Williams, Phillip N.; Keller, Robert A.; Khalil, Lafi S.; Lombardo, Stephen J.; Kharrazi, F. Daniel

    2016-01-01

    Background: Anterior cruciate ligament (ACL) injuries are significant injuries in elite-level basketball players. In-game statistical performance after ACL reconstruction has been demonstrated; however, few studies have reviewed functional performance in National Basketball Association (NBA)–caliber athletes after ACL reconstruction. Purpose: To compare NBA Combine performance of athletes after ACL reconstruction with an age-, size-, and position-matched control group of players with no previous reported knee injury requiring surgery. We hypothesized that there is no difference between the 2 groups in functional performance. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A total of 1092 NBA-caliber players who participated in the NBA Combine between 2000 and 2015 were reviewed. Twenty-one athletes were identified as having primary ACL reconstruction prior to participation in the combine. This study group was compared with an age-, size-, and position-matched control group in objective functional performance testing, including the shuttle run test, lane agility test, three-quarter court sprint, vertical jump (no step), and maximum vertical jump (running start). Results: With regard to quickness and agility, both ACL-reconstructed athletes and controls scored an average of 11.5 seconds in the lane agility test and 3.1 seconds in the shuttle run test (P = .745 and .346, respectively). Speed and acceleration was measured by the three-quarter court sprint, in which both the study group and the control group averaged 3.3 seconds (P = .516). In the maximum vertical jump, which demonstrates an athlete’s jumping ability with a running start, the ACL reconstruction group had an average height of 33.6 inches while the controls averaged 33.9 inches (P = .548). In the standing vertical jump, the ACL reconstruction group averaged 28.2 inches while the control group averaged 29.2 inches (P = .067). Conclusion: In athletes who are able to return to sport

  8. Methods of body mass reduction by combat sport athletes.

    PubMed

    Brito, Ciro José; Roas A, Fernanda Castro Martins; Brito I, Surian Souza; Marins J, Carlos Bouzas; Córdova, Claudio; Franchini, Emerson

    2012-04-01

    The aim of this study was to investigate the methods adopted to reduce body mass (BM) in competitive athletes from the grappling (judo, jujitsu) and striking (karate and tae kwon do) combat sports in the state of Minas Gerais, Brazil. An exploratory methodology was employed through descriptive research, using a standardized questionnaire with objective questions self-administered to 580 athletes (25.0 ± 3.7 yr, 74.5 ± 9.7 kg, and 16.4% ± 5.1% body fat). Regardless of the sport, 60% of the athletes reported using a method of rapid weight loss (RWL) through increased energy expenditure. Strikers tend to begin reducing BM during adolescence. Furthermore, 50% of the sample used saunas and plastic clothing, and only 26.1% received advice from a nutritionist. The authors conclude that a high percentage of athletes uses RWL methods. In addition, a high percentage of athletes uses unapproved or prohibited methods such as diuretics, saunas, and plastic clothing. The age at which combat sport athletes reduce BM for the first time is also worrying, especially among strikers. PMID:22349031

  9. Managing Hypertension in Patients with CKD: A Marathon, Not a SPRINT.

    PubMed

    Chertow, Glenn M; Beddhu, Srinivasan; Lewis, Julia B; Toto, Robert D; Cheung, Alfred K

    2016-01-01

    In this manuscript, nephrologist-investigators from one of five Clinical Center Networks of the Systolic Blood Pressure Intervention Trial (SPRINT) provide background information and context on the intensity of anti-hypertensive therapy in conjunction with the release of detailed results from SPRINT's primary analysis. The authors highlight published evidence on the safety and efficacy of differing intensities of anti-hypertensive therapy in mild to moderate CKD, where SPRINT will help to inform practice, as well as where gaps in evidence will remain. The authors also challenge the nephrology community to renew its attention and efforts on hypertension clinical care and research. PMID:26553785

  10. Anthropometric factors related to sprint and agility performance in young male soccer players

    PubMed Central

    Mathisen, Gunnar; Pettersen, Svein Arne

    2015-01-01

    Objective To investigate the relationship between anthropometrics and sprint and agility performance and describe the development of sprint (acceleration) and agility performance in 10- to 16-year-old male soccer players. Methods One hundred and thirty-two participants were divided into three age groups, 10–12 years (mean 10.8±0.50), 13–14 years (mean 13.9±0.50), and 15–16 years (mean 15.5±0.24), with assessment of 20 m sprint with 10 m split time and agility performance related to body height and body mass within groups. Results In the 10- to 12-year-olds, there were no significant correlations between height, weight, and the performance variables, except for body mass, which was correlated to 10–20 m sprint (r=0.30). In the 13- to 14-year-olds, body height was significantly correlated with 10 m sprint (r=0.50) and 20 m sprint (r=0.52), as well as 10–20 m sprint (r=0.50) and agility performance (r=0.28). In the 15- to 16-year-old group, body height was correlated to 20 m (r=0.38) and 10–20 m (r=0.45) sprint. Body mass was significantly correlated to 10 m spring (r=0.35) in the 13- to 14-year-olds, as well as 20 m (r=0.33) and 10–20 m (r=0.35) sprint in the 15- to 16-year-olds. Conclusion Height and body mass were significantly correlated with sprint performance in 13- to 16-year-old male soccer players. However, the 10- to 12-year-olds showed no significant relationship between sprint performance and anthropometrics, except for a small correlation in 10–20 m sprint. This may be attributed to maturation, with large differences in body height and body mass due to different patterns in the growth spurt. The agility performance related to anthropometrics was insignificant apart from a moderate correlation in the 13- to 14-year-olds. PMID:26604842

  11. Assessment of electrocardiography, echocardiography, and heart rate variability in dynamic and static type athletes

    PubMed Central

    Toufan, Mehrnoush; Kazemi, Babak; Akbarzadeh, Fariborz; Ataei, Amin; Khalili, Majid

    2012-01-01

    Background: Over the last two decades, morphological cardiac changes induced by athletic conditioning have been of great interest. Therefore, several studies have been orchestrated to delineate electrocardiography (ECG), echocardiography, and heart rate variability (HRV) findings in athletes. Purpose: To assess the ECG, echocardiography, and HRV in a group of dynamic and static type athletes. Methods: Fifty professional athletes (20 static and 30 dynamic exercise athletes) and 50 healthy nonathletes (control group) were recruited. Standard 12-lead ECG and transthoracic echocardiography was performed on all athletes and the control group. Through echocardiography, variables including left ventricular (LV) end-diastolic/systolic diameter, LV mass, and left atrial volume index were measured. In addition, both the athletes and the control group underwent ECG Holter monitoring for 15 minutes and several parameters related to HRV (time and frequency domain) were recorded. Results: The most common ECG abnormalities among the athletes were sinus bradycardia and incomplete right bundle branch block. LV end-diastolic diameter and left atrial volume index were significantly greater in the dynamic athletes (P < 0.001). LV end-systolic diameter was significantly lower in the static group (P < 0.001). LV mass of the dynamic and static athletes was significantly greater than that of the controls (P < 0.001). Among the ECG Holter monitoring findings, the dynamic athletes had lower systolic blood pressure than the controls (P = 0.01). Heart rate was lowest in the control group (P < 0.001). Conclusion: The most common ECG abnormalities among adolescent Iranian athletes were sinus bradycardia and incomplete right bundle branch block. Static exercise seemed to reduce LV end-systolic diameter, while dynamic exercise resulted in increased LV end-diastolic diameter and left atrial volume index. Additionally, Iranian athletes showed no differences in HRV parameters, excluding heart rate

  12. Collegiate Athletics: An Investigation into Athletic Persistence of Freshman Student-Athletes Participating in NCAA Division-III Varsity Athletic Programs

    ERIC Educational Resources Information Center

    Sombito, Lester Jamili

    2015-01-01

    Understanding of the persistence of student-athletes in athletics at the D-III level is complex. This research study investigated the issue of student-athlete retention by focusing on Division III (D-III) student-athlete persistence in athletics by asking the following research question, "To what extent do freshman student-athletes persist in…

  13. Angiotensin-converting enzyme/vitamin D receptor gene polymorphisms and bioelectrical impedance analysis in predicting athletic performances of Italian young soccer players.

    PubMed

    Micheli, Matteo Levi; Gulisano, Massimo; Morucci, Gabriele; Punzi, Tiziana; Ruggiero, Marco; Ceroti, Marco; Marella, Mario; Castellini, Elena; Pacini, Stefania

    2011-08-01

    We evaluated the association between 2 genetic polymorphisms known to be involved in fitness and performance, and anthropometric features, body composition, and athletic performances in young male soccer players with the goal of identifying genetic profiles that can be used to achieve maximal results from training. One hundred twenty-five medium-high-level male soccer players were genotyped for angiotensin-converting enzyme (ACE) I/D, and vitamin D receptor (VDR) FokI gene polymorphisms and scored for anthropometric measurements, body composition, and athletic performance. Body mass index, fat mass, fat-free mass, resistance, reactance, impedance, phase angle (PA), and body cell mass were measured. Athletic performance was evaluated by squat jump, countermovement jump (CMJ), 2-kg medicine ball throw, 10- and 20-m sprint time. We observed that the homozygous ff genotype of the VDR gene was significantly more represented in young soccer players than in a matched sedentary population. Values of reactance and PA were differently distributed in ACE and VDR genotypes with high mean values in subjects with DD (ACE) and FF (VDR) genotypes. No correlation was observed between ACE or VDR genotypes and 2-kg medicine ball throw, 10- and 20-m sprint times. The ID genotype of ACE was associated with the best performances in squat jump and CMJ. Our results suggest that determination of ACE and VDR genotypes might help select those young athletes harboring the most favorable genetic potential to succeed in soccer. PMID:21747292

  14. Vaccination in elite athletes.

    PubMed

    Gärtner, Barbara C; Meyer, Tim

    2014-10-01

    Public health vaccination guidelines cannot be easily transferred to elite athletes. An enhanced benefit from preventing even mild diseases is obvious but stronger interference from otherwise minor side effects has to be considered as well. Thus, special vaccination guidelines for adult elite athletes are required. In most of them, protection should be strived for against tetanus, diphtheria, pertussis, influenza, hepatitis A, hepatitis B, measles, mumps and varicella. When living or traveling to endemic areas, the athletes should be immune against tick-borne encephalitis, yellow fever, Japanese encephalitis, poliomyelitis, typhoid fever, and meningococcal disease. Vaccination against pneumococci and Haemophilus influenzae type b is only relevant in athletes with certain underlying disorders. Rubella and papillomavirus vaccination might be considered after an individual risk-benefit analysis. Other vaccinations such as cholera, rabies, herpes zoster, and Bacille Calmette-Guérin (BCG) cannot be universally recommended for athletes at present. Only for a very few diseases, a determination of antibody titers is reasonable to avoid unnecessary vaccinations or to control efficacy of an individual's vaccination (especially for measles, mumps, rubella, varicella, hepatitis B and, partly, hepatitis A). Vaccinations should be scheduled in a way that possible side effects are least likely to occur in periods of competition. Typically, vaccinations are well tolerated by elite athletes, and resulting antibody titers are not different from the general population. Side effects might be reduced by an optimal selection of vaccines and an appropriate technique of administration. Very few discipline-specific considerations apply to an athlete's vaccination schedule mainly from the competition and training pattern as well as from the typical geographical distribution of competitive sites. PMID:24986118

  15. Female Athletes Facing Discrimination: Curriculum Regarding Female Athletes.

    ERIC Educational Resources Information Center

    Palis, Regina

    There continues to be oppression among female athletes, even after the enactment of Title IX in 1972. Female athletes in secondary schools deal with low self-esteem, eating disorders such as anorexia and bulimia, and depression. Female athletes struggle with societal pressures to maintain a model-like figure, while trying to train and perform for…

  16. Athletic Identity of Community College Student Athletes: Issues for Counseling

    ERIC Educational Resources Information Center

    Kissinger, Daniel B.; Newman, Richard; Miller, Michael T.; Nadler, Daniel P.

    2011-01-01

    Community college student athletes are unique in their setting in the world of college student athletes. Many compete for the love of their sport, while others have aspirations for transferring to major colleges to continue their participation. The current study made use of the Athletic Identity Measurement Scale with a sample of nearly 400…

  17. The Academics Athletics Trade-off: Universities and Intercollegiate Athletics

    ERIC Educational Resources Information Center

    Denhart, Matthew; Villwock, Robert; Vedder, Richard

    2009-01-01

    Since beginning in 1852, few issues in higher education have captivated Americans as much as intercollegiate athletics. Intercollegiate athletics is almost uniquely American. Each year, millions of fans attend games and matches between student athletes who provide fans with entertainment while helping bind together communities. Proponents of…

  18. Foot Health Facts for Athletes

    MedlinePlus

    ... pounding their feet endure from... Foot Injuries in Olympic Athletes and Beyond Foot and ankle surgeons offer ... for athletes of all levels. The 2012 Summer Olympics have arrived, and according to foot and ankle ...

  19. Venous Thromboembolism and Marathon Athletes

    MedlinePlus

    ... Heart Association Cardiology Patient Page Venous Thromboembolism and Marathon Athletes Claire M. Hull and Julia A. Harris ... general adult population are indisputable. However, for the marathon athlete who trains intensively and for long periods ...

  20. Health Care Delivery in Athletics.

    ERIC Educational Resources Information Center

    Clarke, Kenneth S.

    1982-01-01

    A structural framework is provided for a responsive athletic injury control program, the Health Supervision Loop in Sport. The use of certified athletic trainers is recommended to lessen the risk of sport-related injuries. (FG)

  1. Epiphyseal injuries in the growing athlete.

    PubMed Central

    Schwab, S. A.

    1977-01-01

    The epiphyses and epiphyseal plates are vital structures in the bone development of the growing athlete. The epiphyseal plate is two to five times weaker than the surrounding fibrous tissue in children and adolescents; consequently a force causing a ligamentous tear in adults is likely to cause an epiphyseal plate injury in growing children. Two types of epiphyseal injury that are common in the growing athlete are (a) separation across the epiphyseal plate, which is usually produced by a direct blow to the joint area or by a strong muscular contraction, and (b) traumatic epiphysitis, the more common of the two, which is usually caused by strong, repetitive contraction of a muscle attached to a traction epiphysis. Each epiphyseal site has specific anatomic features and the forces causing injury differ slightly at each site. An improperly treated separation of an intra-articular pressure epiphysis can have a disastrous effect on the proper functioning of the normally well-fitted articulation of bone ends in the joint. Consequently, proper diagnosis and treatment are essential. Traumatic epiphysitis can result in chronic inflammation or fragmentation, or both, if the condition is not arrested. Therefore the athlete must discontinue the activities that are causing the trauma until the inflammation is completely arrested. Absolute rest may even be required. PMID:902208

  2. Coaching preferences of athletes.

    PubMed

    Terry, P C; Howe, B L

    1984-12-01

    The study examined the coaching preferences of 80 male and 80 female athletes, as measured by the Leadership Scale for Sports (Chelladurai and Saleh, 1978, 1980). In addition, it attempted to assess the applicability to sport of the Life-cycle and Path-goal theories of leadership. Comparisons between groups were made on the basis of sex, age, and type of sport. A MANOVA indicated that athletes in independent sports preferred more democratic behaviour (p less than .001) and less autocratic behaviour (p = .028) than athletes in interdependent sports. No differences in coaching preferences were found which could be attributed to the age or sex of the athlete, or the variability of the sports task. These results partially supported the Path-goal theory, but did not support the Life-cycle theory. Athletes of all groups tended to favour coaches who displayed training behaviour and rewarding behaviour "often", democratic behaviour and social support behaviour "occasionally", and autocratic behaviour "seldom". This consistency may be a useful finding for those organizations and institutions interested in preparing coaches. PMID:6525751

  3. Lower Body Symmetry and Running Performance in Elite Jamaican Track and Field Athletes

    PubMed Central

    Trivers, Robert; Fink, Bernhard; Russell, Mark; McCarty, Kristofor; James, Bruce; Palestis, Brian G.

    2014-01-01

    In a study of degree of lower body symmetry in 73 elite Jamaican track and field athletes we show that both their knees and ankles (but not their feet) are–on average–significantly more symmetrical than those of 116 similarly aged controls from the rural Jamaican countryside. Within the elite athletes, events ranged from the 100 to the 800 m, and knee and ankle asymmetry was lower for those running the 100 m dashes than those running the longer events with turns. Nevertheless, across all events those with more symmetrical knees and ankles (but not feet) had better results compared to international standards. Regression models considering lower body symmetry combined with gender, age and weight explain 27 to 28% of the variation in performance among athletes, with symmetry related to about 5% of this variation. Within 100 m sprinters, the results suggest that those with more symmetrical knees and ankles ran faster. Altogether, our work confirms earlier findings that knee and probably ankle symmetry are positively associated with sprinting performance, while extending these findings to elite athletes. PMID:25401732

  4. Sprint training enhances ionic regulation during intense exercise in men.

    PubMed Central

    McKenna, M J; Heigenhauser, G J; McKelvie, R S; MacDougall, J D; Jones, N L

    1997-01-01

    1. This study investigated the effects of 7 weeks of sprint training on changes in electrolyte concentrations and acid-base status in arterial and femoral venous blood, during and following maximal exercise for 30 s on an isokinetic cycle ergometer. 2. Six healthy males performed maximal exercise, before and after training. Blood samples were drawn simultaneously from brachial arterial and femoral venous catheters, at rest, during the final 10 s of exercise and during 10 min of recovery, and analysed for whole blood and plasma ions and acid-base variables. 3. Maximal exercise performance was enhanced after training, with a 13% increase in total work output and a 14% less decline in power output during maximal cycling. 4. The acute changes in plasma volume, ions and acid-base variables during maximal exercise were similar to previous observations. Sprint training did not influence the decline in plasma volume during or following maximal exercise. After training, maximal exercise was accompanied by lower arterial and femoral venous plasma [K+] and [Na+] across all measurement times (P < 0.05). Arterial plasma lactate concentration ([Lac-]) was greater (P < 0.05), but femoral venous plasma [Lac-] was unchanged by training. 5. Net release into, or uptake of ions from plasma passing through the exercising muscle was assessed by arteriovenous concentration differences, corrected for fluid movements. K+ release into plasma during exercise, and a small net K+ uptake from plasma 1 min post-exercise (P < 0.05), were unchanged by training. A net Na+ loss from plasma during exercise (P < 0.05) tended to be reduced after training (P < 0.06). Release of Lac- into plasma during and after exercise (P < 0.05) was unchanged by training. 6. Arterial and venous plasma strong ion difference ([SID]; [SID] = [Na+] + [K+] - [Lac-] - [Cl-]) were lower after training (mean differences) by 2.7 and 1.8 mmol l-1, respectively (P < 0.05). Arterial and femoral venous CO2 tensions and arterial

  5. EXCEED: an extreme ultraviolet spectrometer onboard SPRINT-A

    NASA Astrophysics Data System (ADS)

    Murakami, Go; Yoshioka, Kazuo; Yamazaki, Atsushi; Uemizu, Kazunori; Ishii, Hiroaki; Uji, Kentaro; Yoshikawa, Ichiro; Kagitani, Masato; Tsuchiya, Fuminori

    2012-09-01

    The extreme ultraviolet (EUV) telescope EXCEED (Extreme Ultraviolet Spectroscope for Exospheric Dynamics) onboard the Japan's small satellite SPRINT-A will be launched in August 2013. The EXCEED instrument will observe tenuous gases and plasmas around the planets in the solar system (e.g., Mercury, Venus, Mars, Jupiter, and Saturn). The EXCEED instrument is designed to have a spectral range of 60-145 nm with a spectral resolution of 0.4-1.0 nm. The instrument has a field of view of 400” x 140” (maximum), and the attitude fluctuations are stabilized within +/-5". The optics of the instrument consists of an entrance mirror with a diameter of 200 mm, three types of slits, two types of filters, a laminar type grating, and a 5-stage microchannel plate assembly with a resistive anode encoder. In this paper, we report the general mission overview, the instrumentations, and the results of ground calibrations.

  6. Neuro-mechanical determinants of repeated treadmill sprints - Usefulness of an "hypoxic to normoxic recovery" approach.

    PubMed

    Girard, Olivier; Brocherie, Franck; Morin, Jean-Benoit; Millet, Grégoire P

    2015-01-01

    To improve our understanding of the limiting factors during repeated sprinting, we manipulated hypoxia severity during an initial set and examined the effects on performance and associated neuro-mechanical alterations during a subsequent set performed in normoxia. On separate days, 13 active males performed eight 5-s sprints (recovery = 25 s) on an instrumented treadmill in either normoxia near sea-level (SL; FiO2 = 20.9%), moderate (MH; FiO2 = 16.8%) or severe normobaric hypoxia (SH; FiO2 = 13.3%) followed, 6 min later, by four 5-s sprints (recovery = 25 s) in normoxia. Throughout the first set, along with distance covered [larger sprint decrement score in SH (-8.2%) compared to SL (-5.3%) and MH (-7.2%); P < 0.05], changes in contact time, step frequency and root mean square activity (surface electromyography) of the quadriceps (Rectus femoris muscle) in SH exceeded those in SL and MH (P < 0.05). During first sprint of the subsequent normoxic set, the distance covered (99.6, 96.4, and 98.3% of sprint 1 in SL, MH, and SH, respectively), the main kinetic (mean vertical, horizontal, and resultant forces) and kinematic (contact time and step frequency) variables as well as surface electromyogram of quadriceps and plantar flexor muscles were fully recovered, with no significant difference between conditions. Despite differing hypoxic severity levels during sprints 1-8, performance and neuro-mechanical patterns did not differ during the four sprints of the second set performed in normoxia. In summary, under the circumstances of this study (participant background, exercise-to-rest ratio, hypoxia exposure), sprint mechanical performance and neural alterations were largely influenced by the hypoxia severity in an initial set of repeated sprints. However, hypoxia had no residual effect during a subsequent set performed in normoxia. Hence, the recovery of performance and associated neuro-mechanical alterations was complete after resting for 6 min near sea level, with a

  7. Speed, force, and power values produced from nonmotorized treadmill test are related to sprinting performance.

    PubMed

    Mangine, Gerald T; Hoffman, Jay R; Gonzalez, Adam M; Wells, Adam J; Townsend, Jeremy R; Jajtner, Adam R; McCormack, William P; Robinson, Edward H; Fragala, Maren S; Fukuda, David H; Stout, Jeffrey R

    2014-07-01

    The relationships between 30-m sprint time and performance on a nonmotorized treadmill (TM) test and a vertical jump test were determined in this investigation. Seventy-eight physically active men and women (22.9 ± 2.7 years; 73.0 ± 14.7 kg; 170.7 ± 10.4 cm) performed a 30-second maximal sprint on the curve nonmotorized TM after 1 familiarization trial. Pearson product-moment correlation coefficients produced significant (p ≤ 0.05) moderate to very strong relationships between 30-m sprint time and body mass (r = -0.37), %fat (r = 0.79), peak power (PP) (r = -0.59), relative PP (r = -0.42), time to peak velocity (r = -0.23) and TM sprint times at 10 m (r = 0.48), 20 m (r = 0.59), 30 m (r = 0.67), 40 m (r = 0.71), and 50 m (r = 0.75). Strong relationships between 30-m sprint time and peak (r = -0.479) and mean vertical jump power (r = -0.559) were also observed. Subsequently, stepwise regression was used to produce two 30-m sprint time prediction models from TM performance (TM1: body mass + TM data and TM2: body composition + TM data) in a validation group (n = 39), and then crossvalidated against another group (n = 39). As no significant differences were observed between these groups, data were combined (n = 72) and used to create the final prediction models (TM1: r = 0.75, standard error of the estimate (SEE) = 0.27 seconds; TM2: r = 0.84, SEE = 0.22 seconds). These final movement-specific models seem to be more accurate in predicting 30-m sprint time than derived peak (r = 0.23, SEE = 0.48 seconds) and mean vertical jump power (r = 0.31, SEE = 0.45 seconds) equations. Consequently, sprinting performance on the TM can significantly predict short-distance sprint time. It, therefore, may be used to obtain movement-specific measures of sprinting force, velocity, and power in a controlled environment from a single 30-second maximal sprinting test. PMID:24950225

  8. Diet Quality of Collegiate Athletes

    ERIC Educational Resources Information Center

    Webber, Kelly; Stoess, Amanda Ireland; Forsythe, Hazel; Kurzynske, Janet; Vaught, Joy Ann; Adams, Bailey

    2015-01-01

    Background/Objectives: Collegiate athletes generally appear healthy according to weight for height and body fat standards. Despite the fact that there are well known connections between athletic performance and nutrition, little is known about the diets of collegiate athletes. The objective of this study was to determine the diet quality of 138…

  9. Abusive Behaviors of College Athletes.

    ERIC Educational Resources Information Center

    Chandler, Steve B.; Johnson, DeWayne J.; Carroll, Pamela S.

    1999-01-01

    Comparison of 126 college athletes and 216 nonathletes on a questionnaire concerning abusive behaviors found that athletes were more often involved in physical abuse of someone of the same sex or sexual abuse of someone of the opposite sex than nonathletes. Athletes reported a history of prior abuse (physical and/or sexual) associated with later…

  10. A Commentary on Collegiate Athletics.

    ERIC Educational Resources Information Center

    Boyd, William B.

    1980-01-01

    The problems of intercollegiate athletics are seen as pathological. Problems discussed include: the bad behavior of fans, players and coaches; cheating; exploitation of athletes; resistance to reforms and public policy (specifically Title IX); the myth of faculty control of athletics; and the bad behavior of the sports media. (MLW)

  11. Strategic Planning for Collegiate Athletics.

    ERIC Educational Resources Information Center

    Yow, Deborah A.; Migliore, R. Henry; Bowden, William W.; Stevens, Robert E.; Loudon, David L.

    This book presents strategies for planning and managing athletic programs. It helps college athletic administrators analyze their organization's environment, set objectives, decide on specific actions, and obtain feedback. Chapter 1, "Perspectives on Planning for Athletics Programs," discusses what planning is and why it is important. Chapter 2,…

  12. Student Attitudes toward Intercollegiate Athletics.

    ERIC Educational Resources Information Center

    Matross, Ronald P.

    1980-01-01

    University students said intercollegiate athletics helped the quality of life at the university, enhanced the personal development of athletes, and provided entertainment. Most wanted to expand women's athletic programs and maintain men's programs. Those who had attended intercollegiate sports events were more favorable than those who had not.…

  13. Sports Nutrition for Young Athletes

    ERIC Educational Resources Information Center

    Cotugna, Nancy; Vickery, Connie E.; McBee, Sheldon

    2005-01-01

    Nutritional needs for peak athletic performance include sufficient calorie intake, adequate hydration, and attention to timing of meals. Student athletes and their advisors often are misinformed or have misconceptions about sports nutrition. This paper identifies nutritional needs of young athletes, reviews common misconceptions, and examines the…

  14. MondoA deficiency enhances sprint performance in mice

    PubMed Central

    Imamura, Minako; Chang, Benny Hung-Junn; Kohjima, Motoyuki; Li, Ming; Hwang, Byounghoon; Taegtmeyer, Heinrich; Harris, Robert A.; Chan, Lawrence

    2015-01-01

    MondoA is a basic helix–loop–helix (bHLH)/leucine zipper (ZIP) transcription factor that is expressed predominantly in skeletal muscle. Studies in vitro suggest that the Max-like protein X (MondoA:Mlx) heterodimer senses the intracellular energy status and directly targets the promoter region of thioredoxin interacting protein (Txnip) and possibly glycolytic enzymes. We generated MondoA-inactivated (MondoA−/−) mice by gene targeting. MondoA−/− mice had normal body weight at birth, exhibited normal growth and appeared to be healthy. However, they exhibited unique metabolic characteristics. MondoA−/− mice built up serum lactate and alanine levels and utilized fatty acids for fuel during exercise. Gene expression and promoter analysis suggested that MondoA functionally represses peroxisome-proliferator-activated receptor γ co-activator-1α (PGC-1α)–mediated activation of pyruvate dehydrogenase kinase 4 (PDK4) transcription. PDK4 normally down-regulates the activity of pyruvate dehydrogenase, an enzyme complex that catalyses the decarboxylation of pyruvate to acetyl-CoA for entry into the Krebs cycle; in the absence of MondoA, pyruvate is diverted towards lactate and alanine, both products of glycolysis. Dynamic testing revealed that MondoA−/− mice excel in sprinting as their skeletal muscles display an enhanced glycolytic capacity. Our studies uncover a hitherto unappreciated function of MondoA in fuel selection in vivo. Lack of MondoA results in enhanced exercise capacity with sprinting. PMID:25145386

  15. Skeletal muscle signature of a champion sprint runner.

    PubMed

    Trappe, Scott; Luden, Nicholas; Minchev, Kiril; Raue, Ulrika; Jemiolo, Bozena; Trappe, Todd A

    2015-06-15

    We had the unique opportunity to study the skeletal muscle characteristics, at the single fiber level, of a world champion sprint runner who is the current indoor world record holder in the 60-m hurdles (7.30 s) and former world record holder in 110-m hurdles (12.91 s). Muscle biopsies were obtained from the vastus lateralis at rest and 4 h after a high-intensity exercise challenge (4 × 7 repetitions of resistance exercise). Single muscle fiber analyses were conducted for fiber type distribution (myosin heavy chain, MHC), fiber size, contractile function (strength, speed, and power) and mRNA expression (before and after the exercise bout). The world-class sprinter's leg muscle had a high abundance (24%) of the pure MHC IIx muscle fibers with a total fast-twitch fiber population of 71%. Power output of the MHC IIx fibers (35.1 ± 1.4 W/l) was 2-fold higher than MHC IIa fibers (17.1 ± 0.5 W/l) and 14-fold greater than MHC I fibers (2.5 ± 0.1 W/l). Additionally, the MHC IIx fibers were highly responsive to intense exercise at the transcriptional level for genes involved with muscle growth and remodeling (Fn14 and myostatin). To our knowledge, the abundance of pure MHC IIx muscle fibers is the highest observed in an elite sprinter. Further, the power output of the MHC IIa and MHC IIx muscle fibers was greater than any human values reported to date. These data provide a myocellular basis for the high level of sprinting success achieved by this individual. PMID:25749440

  16. Relationship between muscular strength and sprints with changes of direction.

    PubMed

    Castillo-Rodríguez, Alfonso; Fernández-García, José C; Chinchilla-Minguet, José L; Carnero, Elvis Álvarez

    2012-03-01

    Sprints with changes of direction (COD) have been traditionally associated with performance in team sports. Jumping tests have been used as predictors of COD; however, there are not too many studies analyzing how dominance affects the best performance of the turn. The purpose of this study was to explore the relationship between tests pertaining to jumps (1 and 2 legs) and COD (right and left turns). Forty-two male students were selected at the Faculty of Physical Education (age: 20.1 ± 3.7 years; weight: 73.4 ± 8.4 kg; body mass index: 23.1 ± 2.6 kg·m(-2); and fat mass: 17.1 ± 8.8%). All the subjects had right leg dominance. The COD tests were assessed using three 10-m sprint tests (90° right and left turns and 180° turn). Jumps were countermovement jumps (CMJs with 1 and 2 legs) and the drop jump (DJ). Pearson coefficient correlation and stepwise regression analyses were performed. Our results showed that both CMJs and DJs were associated with COD. The CMJ with the right leg had the best coefficient correlation with left COD time (r = -0.64; p < 0.01). Also, the CMJ was associated with COD180° time (r = -0.60; p < 0.01). After regression analysis, only right one-leg CMJ and CMJ were predictors of left COD time (adjusted R2 = 0.46; p < 0.01). The main finding of this study was that the CMJ, but not the DJ, was the best predictor of dominant side COD. Jumps are an important component of team sport training because they improve COD performance. However, coaches use several types of jumps during training; our results suggest that jumps similar to the CMJ should be useful tools to improve COD, which helps to specify better training prescription. PMID:22289697

  17. Sprint Interval and Sprint Continuous Training Increases Circulating CD34+ Cells and Cardio-Respiratory Fitness in Young Healthy Women

    PubMed Central

    Harris, Emma; Rakobowchuk, Mark; Birch, Karen M.

    2014-01-01

    Introduction The improvement of vascular health in the exercising limb can be attained by sprint interval training (SIT). However, the effects on systemic vascular function and on circulating angiogenic cells (CACs) which may contribute to endothelial repair have not been investigated. Additionally, a comparison between SIT and sprint continuous training (SCT) which is less time committing has not been made. Methods 12 women (22±2 yrs) completed 12 sessions of either SIT (n = 6) or work-matched SCT (n = 6) on 3 days/week. Pre and post-training assessments included brachial artery endothelial function and peripheral blood analysis for CAC number (CD34+/CD34+CD45dim). CAC function was measured by migration and adhesion assays. Cardio-respiratory fitness, carotid arterial stiffness and carotid-radial and brachial-foot pulse wave velocity (PWV) were also evaluated. Results CD34+ CACs increased following training in both groups but CD34+CD45dim did not (Pre CD34+: 40±21/105 leukocytes, Post CD34+: 56±24/105 leukocytes, main time effect p<0.05). Brachial artery flow-mediated dilation (FMD) increased following SIT but SCT had no effect (Pre SIT: 5.0±3.4%, Post SIT: 5.9±3.0%, Pre SCT: 7.2±2.7%, Post SCT: 6.5±2.9%; group x time interaction p = 0.08). increased in both training groups (Pre: 34.6±4.6 ml•kg•ml−1, Post: 36.9±5.4 ml•kg•ml−1, main time effect p<0.05). CAC function, carotid arterial stiffness and PWV did not change after training (p>0.05). Discussion SCT involving little time commitment is comparable to SIT in increasing CD34+ cell number and . An increased mobilisation of CD34+ CACs suggests that sprint training may be an effective method to enhance vascular repair. PMID:25265043

  18. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test

    PubMed Central

    Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

    2016-01-01

    Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg-1 friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key points The Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring. This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase. This maximal power output improvement was independent from the shoe-pedal linkage condition. Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences. PMID:27274658

  19. Predictors of sprint start speed: the effects of resistive ground-based vs. inclined treadmill training.

    PubMed

    Myer, Gregory D; Ford, Kevin R; Brent, Jensen L; Divine, Jon G; Hewett, Timothy E

    2007-08-01

    There is currently no consensus with regard to the most effective method to train for improved acceleration, or with regard to which kinematic variable provides the greatest opportunity for improvement in this important performance characteristic. The purpose of this study was to determine the effects of resistive ground-based speed training and incline treadmill speed training on speed-related kinematic measures and sprint start speed. The hypothesis tested was that incline treadmill training would improve sprint start time, while the ground-based resistive training would not. Corollary hypotheses were that treadmill training would increase stride frequency and ground-based training would not affect kinematics during the sprint start. Thirty-one high school female soccer players (15.7 +/- 0.5 years) were assigned to either treadmill (n = 17) or ground-based (n = 14) training groups and trained 2 times a week for 6 weeks. The treadmill group utilized incline speed training on a treadmill, while the ground-based group utilized partner band resistance ground-based techniques. Three-dimensional motion analysis was used (4.5 m mark) before and after training to quantify kinematics during the fastest of 3 recorded sprint starts (9.1 m). Both groups decreased average sprint start time from 1.75 +/- 0.12 to 1.68 +/- 0.08 seconds (p < 0.001). Training increased stride frequency (p = 0.030) but not stride length. After training, total vertical pelvic displacement and stride length predicted 62% of the variance in sprint start time for the resistive ground-based group, while stride length and stride frequency accounted for 67% prediction of the variance in sprint start time for the treadmill group. The results of this study indicate that both incline treadmill and resistive ground-based training are effective at improving sprint start speed, although they potentially do so through differing mechanisms. PMID:17685716

  20. Effect of acute interval sprinting exercise on postprandial lipemia of sedentary young men

    PubMed Central

    Chu, Aaron; Boutcher, Yati N; Boutcher, Stephen H

    2016-01-01

    [Purpose] Postprandial lipemia (PPL) contributesto the development of atherosclerosis. In females, repeated 8-second bouts of interval sprinting exercise reduced PPL, however, the effect of 8-second bouts of interval sprinting on PPL of overweight males is undetermined. Thus, the effect of 8-secondsof interval sprinting for 20 min, the night before ingestion of a high-fat meal (HFM), on plasma triacylglycerol(TG) levelswas examined. [Methods] Ten overweight males acted as participants (BMI = 26±3.0kg/m2, age 22 ± 2.5 years). A crossover design was employed withinterval sprinting and a noexercise condition separated by 7days. Participants consumed a milkshake (high-fat meal;HFM = 4170 kJ/993 Kcal) the morning after an overnight fast, followed by 4 hourly blood samples. Participants performedone bout of interval sprinting (8seconds sprinting at 110-115rpm, 12seconds active recovery at ~60rpm for 20 minutes) the evening before the consumption of the HFM. [Results] Postprandial TG was 22.5% lower in the interval sprinting compared to the noexercise condition when comparing the change in total area under the curve (ΔAUCT): ISE(7.15±1.90mmolL-1h-1) versus noexercise (9.22±3.44mmolL-1h-1), p=.014. The correlation between fasting TG levels in the noexercise condition and total reduction in AUCT between the conditions was significant (r=.87, p=.001). [Conclusion] One 20-min bout of interval sprinting,the night before consumption of a HFM,significantly attenuated the PPL response of sedentary males. PMID:27298807

  1. Effects of coffee and caffeine anhydrous on strength and sprint performance.

    PubMed

    Trexler, Eric T; Smith-Ryan, Abbie E; Roelofs, Erica J; Hirsch, Katie R; Mock, Meredith G

    2016-09-01

    Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300 mg flat dose; yielding 3-5 mg/kg bodyweight), COF (8.9 g; 303 mg caffeine), or placebo (PLA; 3.8 g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p = .04), but not PLA (p = .99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p > .05). There were no sprint × treatment interactions for PP or TW (p > .05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise. PMID:26394649

  2. Effects of a Non-Circular Chainring on Sprint Performance During a Cycle Ergometer Test.

    PubMed

    Hintzy, Frédérique; Grappe, Frédéric; Belli, Alain

    2016-06-01

    Non-circular chainrings have been reported to alter the crank angular velocity profile over a pedal revolution so that more time is spent in the effective power phase. The purpose of this study was to determine whether sprint cycling performance could be improved using a non-circular chainring (Osymetric: ellipticity 1.25 and crank lever mounted nearly perpendicular to the major axis), in comparison with a circular chainring. Twenty sprint cyclists performed an 8 s sprint on a cycle ergometer against a 0.5 N/kg(-1) friction force in four crossing conditions (non-circular or circular chainring with or without clipless pedal). Instantaneous force, velocity and power were continuously measured during each sprint. Three main characteristic pedal downstrokes were selected: maximal force (in the beginning of the sprint), maximal power (towards the middle), and maximal velocity (at the end of the sprint). Both average and instantaneous force, velocity and power were calculated during the three selected pedal downstrokes. The important finding of this study was that the maximal power output was significantly higher (+ 4.3%, p < 0.05) when using the non-circular chainring independent from the shoe-pedal linkage condition. This improvement is mainly explained by a significantly higher instantaneous external force that occurs during the downstroke. Non-circular chainring can have potential benefits on sprint cycling performance. Key pointsThe Osymetric non-circular chainring significantly maximized crank power by 4.3% during sprint cycling, in comparison with a circular chainring.This maximal power output improvement was due to significant higher force developed when the crank was in the effective power phase.This maximal power output improvement was independent from the shoe-pedal linkage condition.Present benefits provided by the non-circular chainring on pedalling kinetics occurred only at high cadences. PMID:27274658

  3. The Effect of Passive versus Active Recovery on Power Output over Six Repeated Wingate Sprints

    ERIC Educational Resources Information Center

    Lopez, Egla-Irina D.; Smoliga, James M.; Zavorsky, Gerald S.

    2014-01-01

    Purpose: The aim of this study was to examine the effect of active versus passive recovery on 6 repeated Wingate tests (30-s all-out cycling sprints on a Velotron ergometer). Method: Fifteen healthy participants aged 29 (SD = 8) years old (body mass index = 23 [3] kg/m[superscript 2]) participated in 3 sprint interval training sessions separated…

  4. Osteitis pubis in athletes.

    PubMed

    Beatty, Tricia

    2012-01-01

    Osteitis pubis is one of many etiologies of groin pain in athletes. It is a painful overuse injury of the pubic symphysis and the parasymphyseal bone that typically is found in athletes whose sports involve kicking, rapid accelerations, decelerations, and abrupt directional changes. Athletes most commonly present with a complaint of anterior and/or medial groin pain but also can present with lower abdominal, adductor, inguinal, perineal, and/or scrotal pain. Symptoms can be severe and can limit participation in sport until treatment is instituted. Imaging is useful for ruling out other etiologies of groin pain, identifying concomitant pathology, and confirming the diagnosis itself. Treatment is varied but usually includes nonoperative measures of rest, rehabilitation, and/or pharmacotherapy and also may include injections and/or surgical procedures. A high clinical suspicion should exist when evaluating soccer, rugby, or American football players and distance runners who present with complaints of groin pain. PMID:22410702

  5. Dental problems in athletes.

    PubMed

    Inouye, Jill; McGrew, Chris

    2015-01-01

    Orofacial injuries and diseases occur in athletes, and they may not always have access to dentists. Therefore team physicians should be aware of the common injuries and initial management. Treatment of dental injuries will depend on whether the teeth are primary or permanent. The most common type of fracture is crown fracture, but there are other dental injuries that can lead to future complications if not treated promptly and monitored closely. Tooth avulsions need to be handled properly, and athletes should see a dentist as soon as possible. Despite the urgency of some injuries, other orofacial injuries or diseases, such as lacerations and caries, should not be overlooked. Proper education and use of mouth guards can assist athletes in reducing their risk of orofacial injuries. PMID:25574879

  6. [Musculoskeletal rehabilitation and bone. Abnormal bone metabolism in female elite athletes].

    PubMed

    Enatsu, Akiko

    2010-04-01

    Recently, female athletes are particularly well, the other hand, many athletes suffer from amenorrhea due to excessive training. Especially, in sports with weight restrictions, they suffer from "Female athlete triad" , eating disorders, amenorrhea and osteoporosis. Amenorrhea is nothing else than a lack of estrogen, action on bone resorption and promote bone formation, by neglect this, it lead to osteoporosis and a stress fracture, and they would often give up their career as elite athletes. So we should consider it as serious sports injury. The problems of amenorrhea is should be recognized as a deficiency of estrogen. A Case of amenorrhea in female athletes, it is necessary to consider the hormone replacement therapy based on the appropriate diagnosis. However, it is important to start the management of body fat and body weight and strength of exercises since adolescent for the prevention the amenorrhea. PMID:20354328

  7. Caffeine's effect on intermittent sprint cycling performance with different rest intervals.

    PubMed

    Lee, Chia-Lun; Cheng, Ching-Feng; Lin, Jung-Charng; Huang, Hsin-Wei

    2012-06-01

    The purpose of this study was to investigate the effects of caffeine ingestion on the performance of an intermittent sprint cycling test (ISCT) with different rest intervals. Fourteen males with team sport experience consumed 6 mg kg(-1) of caffeine or a placebo 60 min prior to completing two sets of an ISCT with 4-min rest intervals. Each set consisted of 12 × 4-s sprints with 20- or 90-s active recovery intervals at 60-70 rpm. Blood lactate was collected at baseline and immediately following the completion of six sprints in each set. At 20-s recovery intervals, peak power and total work were not significantly different between conditions during the ISCT (P > 0.05); but caffeine reduced 6.31% effort for mean power in Sprint 10 of the later stage, as well as an increased fatigue index and elevated blood lactate levels during the ISCT (P < 0.05). At 90-s recovery intervals, peak power, mean power, and total work under caffeine conditions were significantly higher than under placebo conditions during the ISCT (P < 0.05), but no differences were apparent in fatigue index and blood lactate levels (P > 0.05). In conclusion, caffeine ingestion may be ergolytic, affecting performance and fatigue development in the later stage during a prolonged and intermittent sprint test with a short recovery interval. However, caffeine produces an ergogenic effect in the initial stage of an intermittent sprint performance with a longer recovery interval. PMID:21960086

  8. Relationship between Repeated Sprint Ability and Aerobic Capacity in Professional Soccer Players

    PubMed Central

    Jones, Rhys M.; Cook, Christian C.; Kilduff, Liam P.; Milanović, Zoran; James, Nic; Sporiš, Goran; Fiorentini, Bruno; Fiorentini, Fredi; Turner, Anthony; Vučković, Goran

    2013-01-01

    Aim. The aim of the present study was to investigate the relationship between maximal aerobic capacity (VO2 max) and repeated sprint ability (RSA) in a group of professional soccer players. Methods. Forty-one professional soccer players (age 23 ± 4 yrs, height 180.0 ± 5.3 cm, weight 79.6 ± 5.3 kg) were required to perform tests to assess RSA and VO2 max on two separate days with at least 48 hr rest between testing sessions. Each player performed a treadmill test to determine their VO2 max and a test for RSA involving the players completing 6 × 40 m sprints (turn after 20 m) with 20 s active recovery between each sprint. Results. There was a significant negative correlation between body mass normalised VO2 max and mean sprint time (RSAmean) (r = −0.655; P < 0.01) and total sprint time (RSAtotal) (r = −0.591, P < 0.01). Conclusion. Results of the current study indicate that VO2 max is one important factor aiding soccer players in the recovery from repeated sprint type activities. PMID:24198732

  9. Reduction in plasma leucine after sprint exercise is greater in males than in females.

    PubMed

    Esbjörnsson, M; Rooyackers, O; Norman, B; Rundqvist, H C; Nowak, J; Bülow, J; Simonsen, L; Jansson, E

    2012-06-01

    There is a pronounced gender difference in the accumulation of plasma ammonia after sprint exercise. Ammonia is a key intermediate in amino acid metabolism, which implies that gender-related differences in plasma and muscle amino acid concentrations after sprint exercise exist. To study this, three bouts of 30-s sprint exercise were performed by healthy females (n=8) and males (n=6). Blood leucine and muscle leucine were collected over the exercise period. Basal arterial plasma and skeletal muscle leucine were 40% higher in males than females (P<0.010 and P<0.020). Plasma, but not muscle, leucine decreased by sprint exercise and more so in males than females (g × t: P=0.025). Increase in ammonia was higher in males than females in both plasma and muscle (g × t: P<0.001 and P=0.003). An opposite pattern was shown for plasma glutamine, where an increase was found in females (P<0.001), but not in males. In conclusion, the lower plasma ammonia after sprint exercise in females seems to be explained by a lower accumulation of ammonia in skeletal muscle and by a buffering of ammonia in the form of glutamine in females. The greater reduction in plasma leucine in males seems to be related to their greater increase in muscle ammonia after sprint exercise. PMID:22612362

  10. The Relationship Between Body Composition, Anaerobic Performance and Sprint Ability of Amputee Soccer Players

    PubMed Central

    Özkan, Ali; Kayıhan, Gürhan; Köklü, Yusuf; Ergun, Nevin; Koz, Mitat; Ersöz, Gülfem; Dellal, Alexandre

    2012-01-01

    The purpose of the present study was to investigate the relationship between body composition, anaerobic performance and sprint performance of amputee soccer players. Fifteen amputee soccer players participated in this study voluntarily. Subjects’ height, body weight, body mass index, body fat percentage (Jackson and Pollock formula) and somatotype characteristics (Heath-Carter system) were determined. The sprint performance at 10m, 20m and 30m was evaluated, whereas the counter movement jump (CMJ), relative CMJ (RCMJ), squat jump (SJ) and relative SJ (RSJ) tests were used for the determination of anaerobic performance. The results of the Pearson Product Moment correlation analysis indicated that body composition was significantly correlated with CMJ and SJ (p < 0.01), on the other hand, no measure of body composition was significantly related to the other component (p > 0.05). A significant correlation was found between CMJ, RCMJ, SJ, 10 m, 20 m and 30 m sprint performance (p < 0.05); whereas, in contrast, no measure of body composition was significantly related to the 10 m, 20 m and 30 m sprint performance (p > 0.05). In conclusion, the findings of the present study indicated that sprint performance was described as an essential factor in anaerobic performance whereas body composition and somatotype play a determinant role in anaerobic and sprint performance in amputee soccer players. PMID:23486067

  11. Modeling Longitudinal Changes in 5 m Sprinting Performance Among Young Male Tennis Players.

    PubMed

    Kramer, Tamara; Valente-Dos-Santos, João; Coelho-E-Silva, Manuel J; Malina, Robert M; Huijgen, Barbara C H; Smith, Joanne; Elferink-Gemser, Marije T; Visscher, Chris

    2016-02-01

    Year-to-year changes in sprinting in youth tennis players were examined in a mixed-longitudinal study (256 male players, aged 10-15 years: 993 measurements). Height (h), body mass (BM), lower limb explosive strength (LLES), and a 5-m sprint were measured over five years. During that period, players were classified as elite or sub-elite. To account for the repeated measurements within the individual nature of longitudinal data, multilevel random effects regression analyses were used. Sprint performance improved with age at each additional 1 year of age, thus predicting ∼.016 sec improvement in five-meter sprint time by all variables of the model. It was possible to predict the performance of elite tennis players in the 5-m sprint (sec) for elite players (1.1493 - (0.0159 ċ centered age) - (0.009 ċ BM) - (0.044 ċ LLES) and sub-elite players (1.1493 - (0.0159 ċ centered age) + 0.0135 - (0.009 ċ BM) - (0.044 ċ LLES) - (0.0557 ċ centered age). Sprint performance differences between elite and sub-elite players was related to longitudinal changes in body size and lower limb strength up until age 13. PMID:27420323

  12. Arrhythmias in the athlete.

    PubMed

    Bisbal, F; Mont, L

    2012-06-01

    Regular exercise provides substantial health benefits, mostly by reducing cardiovascular risk factors. However, it may also trigger acute cardiac events and cause sudden cardiac death in individuals with a pre-existing condition. In an otherwise healthy population, intense regular exercise may lead to morphological and electrical cardiac adaptations commonly referred as "athlete's heart." Recent data suggest that this may itself produce structural changes of atrial and ventricular myocardium with enlargement and fibrosis, creating the substrate for development of arrhythmias in apparently healthy athletes. The state of the art in this controversial issue is reviewed. PMID:22782729

  13. Groin pain in athletes.

    PubMed

    Hureibi, K A; McLatchie, G R

    2010-05-01

    Groin pain in athletes is a common problem in sport medicine, and remains a diagnostic challenge. It is more common with sports that involve kicking, rapid accelerations and decelerations, and sudden direction changes. There is an extensive differential diagnosis and overlap in signs between possible diagnoses. It is important to appreciate the anatomy of the groin and undertake a careful history and examination. Adductor strain, groin disruption and osteitis pubis are among the common causes. The aim of this article is to briefly review the most common causes of groin pain in athletes. The diagnosis and management of these conditions are briefly discussed. PMID:20533693

  14. Trainability of Young Athletes and Overtraining

    PubMed Central

    Matos, Nuno; Winsley, Richard J.

    2007-01-01

    Exercise adaptations to strength, anaerobic and aerobic training have been extensively studied in adults, however, young people appear to respond differently to such exercise stimulus in comparison to adults. In addition, because overtraining in young athletes has received little attention, this important area is also discussed. Resistance training in children can be safe and effective. It has the potential to improve sport performance, enhance body composition and reduce the rate of sport incurred injury. Furthermore, with the appropriate stimulus, prepubertal and adolescent athletes can show significant increments in muscle strength (13 - 30%). Children can improve anaerobic power (3%-10% Mean Power and 4%-20% in Peak Power), although the mechanisms responsible for the improvements in children remain unclear. Children show a ‘reduced’ trainability of peak VO2 in comparison to adults. Nevertheless, their aerobic power is trainable, with improvements reported at approximately 5%. Moreover, improvements in other variables like exercise economy or lactate threshold may occur without significant changes in peak VO2 The limited evidence available indicates that overtraining is occurring in young athletes (30% prevalence), highlighting the importance of further research in to all the possible contributing factors - physiological, psychological and emotional - when investigating overtraining. Key pointsChildren’s strength, anaerobic and aerobic power is trainable, although the improvements may be smaller than seen in adults.Children can demonstrate significant gains in muscle strength with resistance training (13 - 30%).Improvements in mean power (3 - 10%) and peak power (4 - 20%) are reported in children.Aerobic fitness can improve with training in children by approximately 5%.Limited available evidence indicates an occurrence of overtraining in young athletes of around 30%. PMID:24149422

  15. Health-risk behaviors among high school athletes and preventive services provided during sports physicals

    PubMed Central

    Johnson, Karen E.; McRee, Annie-Laurie

    2014-01-01

    Introduction Pre-participation exams (PPEs), or sports physicals, present opportunities for health care providers to identify and discuss common adolescent health-risk behaviors. We sought to examine the prevalence of health-risk behaviors among high school athletes, and the proportion of providers who address these behaviors during PPEs. Method We used data from two statewide surveys: a survey of adolescents (n=46,492) and a survey of nurse practitioners and physicians (n=561) for this descriptive study. Results The most prevalent risk behaviors reported by student athletes were: low levels of physical activity (70%), bullying perpetration (41%), and alcohol use (41%). Most providers (≥75%) addressed many common risk behaviors during PPEs but fewer addressed bullying, violence, and prescription drug use. Topics discussed differed by provider type and patient population. Discussion Many providers addressed critical threats to adolescent health during PPEs but findings suggest potential disconnects between topics addressed during PPEs and behaviors of athletes. PMID:25043289

  16. Exploring the potential for changing gender norms among cricket coaches and athletes in India.

    PubMed

    Miller, Elizabeth; Das, Madhumita; Verma, Ravi; O'Connor, Brian; Ghosh, Sancheeta; Jaime, Maria Catrina D; McCauley, Heather L

    2015-02-01

    This study explored gender norms with cricket coaches and athletes in India to adapt a coach-delivered gender violence prevention program from the United States for the urban Indian context. Interviews and focus groups conducted among coaches and adolescent cricketers highlight the extent to which coaches and athletes articulate prevailing inequitable notions about gender and recognition of the power coaches wield. Adapting a violence prevention program that emphasizes gender norms change may be feasible with Indian cricket coaches but is likely to require attention to defining gender equity and challenging cultural assumptions with coaches prior to implementing the program with athletes. PMID:25540256

  17. The Research on the High-Protein Low-Calorie Food Recipe for Teenager Gymnastics Athletes

    PubMed Central

    Wei, Cong

    2015-01-01

    In order to prevent teenager gymnastics athletes getting fat deposition, weight gain, they should supply a rational food. This paper considers the normal growth and development of athletes, body fat deposition proteins and hunger feel, configured high-protein low-calorie food recipe. Then analysis the composition and the essential amino acids of the recipe. In the final choiced 18 adolescent gymnastics athletes as subjects, to verify the validity of the formula. And analysis the experimental results. The experimental results analysis shows that this recipe basically meets the design requirements. PMID:26628935

  18. The Research on the High-Protein Low-Calorie Food Recipe for Teenager Gymnastics Athletes.

    PubMed

    Wei, Cong

    2015-01-01

    In order to prevent teenager gymnastics athletes getting fat deposition, weight gain, they should supply a rational food. This paper considers the normal growth and development of athletes, body fat deposition proteins and hunger feel, configured high-protein low-calorie food recipe. Then analysis the composition and the essential amino acids of the recipe. In the final choiced 18 adolescent gymnastics athletes as subjects, to verify the validity of the formula. And analysis the experimental results. The experimental results analysis shows that this recipe basically meets the design requirements. PMID:26628935

  19. Epidemiologic Comparison of Injured High School Basketball Athletes Reporting to Emergency Departments and the Athletic Training Setting

    PubMed Central

    Fletcher, Erica N.; McKenzie, Lara B.; Comstock, R. Dawn

    2014-01-01

    Context: Basketball is a popular US high school sport with more than 1 million participants annually. Objective: To compare patterns of athletes with basketball-related injuries presenting to US emergency departments from 2005 through 2010 and the high school athletic training setting from the 2005–2011 seasons. Design: Descriptive epidemiology study. Setting: Data from the National Electronic Injury Surveillance System of the US Consumer Product Safety Commission and the High School Reporting Information Online database. Main Outcome Measure(s): Complex sample weights were used to calculate national estimates of basketball-related injuries for comparison. Patients or Other Participants: Adolescents from 13 to 19 years of age treated in US emergency departments for basketball-related injuries and athletes from 13 to 19 years of age from schools participating in High School Reporting Information Online who were injured while playing basketball. Results: Nationally, an estimated 1 514 957 (95% confidence interval = 1 337 441, 1 692 474) athletes with basketball-related injuries reported to the emergency department and 1 064 551 (95% confidence interval = 1 055 482, 1 073 620) presented to the athletic training setting. Overall, the most frequent injuries seen in the emergency department were lacerations and fractures (injury proportion ratios [IPRs] = 3.45 and 1.72, respectively), whereas those seen in the athletic training setting were more commonly concussions and strains/sprains (IPRs = 2.23 and 1.19, respectively; all P values < .0001). Comparisons of body site and diagnosis combinations revealed additional differences. For example, athletes with lower leg fractures more often presented to the emergency department (IPR = 6.53), whereas those with hand fractures more frequently presented to the athletic training setting (IPR = 1.18; all P values < .0001). Conclusions: Patterns of injury differed among high school basketball players

  20. Percentile Values for Running Sprint Field Tests in Children Ages 6-17 Years: Influence of Weight Status

    ERIC Educational Resources Information Center

    Castro-Pinero, Jose; Gonzalez-Montesinos, Jose Luis; Keating, Xiaofen D.; Mora, Jesus; Sjostrom, Michael; Ruiz, Jonatan R.

    2010-01-01

    The aim of this study was to provide percentile values for six different sprint tests in 2,708 Spanish children (1,234 girls) ages 6-17.9 years. We also examined the influence of weight status on sprint performance across age groups, with a focus on underweight and obese groups. We used the 20-m, 30-m, and 50-m running sprint standing start and…

  1. Acute supra-therapeutic oral terbutaline administration has no ergogenic effect in non-asthmatic athletes.

    PubMed

    Sanchez, Anthony M J; Borrani, Fabio; Le Fur, Marie Amélie; Le Mieux, Anais; Lecoultre, Virgile; Py, Guillaume; Gernigon, Christophe; Collomp, Katia; Candau, Robin

    2013-02-01

    This study aimed to investigate the effects on a possible improvement in aerobic and anaerobic performance of oral terbutaline (TER) at a supra-therapeutic dose in 7 healthy competitive male athletes. On day 1, ventilatory threshold, maximum oxygen uptake [Formula: see text] and corresponding power output were measured and used to determine the exercise load on days 2 and 3. On days 2 and 3, 8 mg of TER or placebo were orally administered in a double-blind process to athletes who rested for 3 h, and then performed a battery of tests including a force-velocity exercise test, running sprint and a maximal endurance cycling test at Δ50 % (50 % between VT and [Formula: see text]). Lactatemia, anaerobic parameters and endurance performance ([Formula: see text] and time until exhaustion) were raised during the corresponding tests. We found that TER administration did not improve any of the parameters of aerobic performance (p > 0.05). In addition, no change in [Formula: see text] kinetic parameters was found with TER compared to placebo (p > 0.05). Moreover, no enhancement of the force-velocity relationship was observed during sprint exercises after TER intake (p > 0.05) and, on the contrary, maximal strength decreased significantly after TER intake (p < 0.05) but maximal power remained unchanged (p > 0.05). In conclusion, oral acute administration of TER at a supra-therapeutic dose seems to be without any relevant ergogenic effect on anaerobic and aerobic performances in healthy athletes. However, all participants experienced adverse side effects such as tremors. PMID:22767151

  2. Paths to Expertise in Portuguese National Team Athletes

    PubMed Central

    Leite, Nuno; Baker, Joseph; Sampaio, Jaime

    2009-01-01

    The purpose of this study was to identify the quantity and type of sporting activities undertaken by expert team sport athletes in the earlier stages of the long- term athlete development. Experts in roller-hockey (n = 19), volleyball (n = 14), soccer (n = 42) and basketball (n = 37) provided detailed information about the sporting activities they undertook throughout their careers. Results showed considerable variation between and within sports; however, generally, athletes began participating in sports between 6 and 10 years of age. The pattern of participation in specific and non-specific (team, individual and combat) sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. Our results suggest that involvement in multiple sports during early stages of development is an alternative to early specialization and add further evidence of the complexity of skill acquisition in sport. Key points Although most athletes began sport participation between 6 and 10 years of age, there was significant variation across groups suggesting considerable flexibility in the pathways to expertise. The path to expertise in volleyball was clearly distinct from the paths of basketball, soccer and roller-hockey. There is a considerable involvement in sports other than the athlete’s primary sport, suggesting early specialization is not required for these sports. The pattern of participation in specific and non-specific sports for each stage of involvement demonstrated an increase in the number of activities participated in until early adolescence. PMID:24149598

  3. Child and Adolescent Athletes with Diabetes.

    ERIC Educational Resources Information Center

    Blackett, Piers R.

    1988-01-01

    Exercise may be a useful element in teaching diabetic children to control the disease. Controlling glucose levels during exercise requires close regulation of diet and insulin. Practical and medical aspects of exercise for diabetics are discussed, as well as its physical benefits, such as a strengthened heart. (JL)

  4. Commercialism in Intercollegiate Athletics.

    ERIC Educational Resources Information Center

    Delany, James E.

    1997-01-01

    Outlines the history of intercollegiate athletics and the evolution of commercialization in college sports, particularly through television. Argues that few Division I programs could be self-sufficient; the issue is the degree to which sports are commercialized for revenue, and the challenge to balance schools' needs, private sector interests, and…

  5. Drug abuse in athletes

    PubMed Central

    Reardon, Claudia L; Creado, Shane

    2014-01-01

    Drug abuse occurs in all sports and at most levels of competition. Athletic life may lead to drug abuse for a number of reasons, including for performance enhancement, to self-treat otherwise untreated mental illness, and to deal with stressors, such as pressure to perform, injuries, physical pain, and retirement from sport. This review examines the history of doping in athletes, the effects of different classes of substances used for doping, side effects of doping, the role of anti-doping organizations, and treatment of affected athletes. Doping goes back to ancient times, prior to the development of organized sports. Performance-enhancing drugs have continued to evolve, with “advances” in doping strategies driven by improved drug testing detection methods and advances in scientific research that can lead to the discovery and use of substances that may later be banned. Many sports organizations have come to ban the use of performance-enhancing drugs and have very strict consequences for people caught using them. There is variable evidence for the performance-enhancing effects and side effects of the various substances that are used for doping. Drug abuse in athletes should be addressed with preventive measures, education, motivational interviewing, and, when indicated, pharmacologic interventions. PMID:25187752

  6. The Female Athlete Triad

    PubMed Central

    Nazem, Taraneh Gharib; Ackerman, Kathryn E.

    2012-01-01

    Context: The female athlete triad (the triad) is an interrelationship of menstrual dysfunction, low energy availability (with or without an eating disorder), and decreased bone mineral density; it is relatively common among young women participating in sports. Diagnosis and treatment of this potentially serious condition is complicated and often requires an interdisciplinary team. Evidence Acquisition: Articles from 1981 to present found on PubMed were selected for review of major components of the female athlete triad as well as strategies for diagnosis and treatment of the conditions. Results: The main goal in treatment of young female athletes with the triad is a natural return of menses as well as enhancement of bone mineral density. While no specific drug intervention has been shown to consistently improve bone mineral density in this patient population, maximizing energy availability and optimizing vitamin D and calcium intake are recommended. Conclusions: Treatment requires a multidisciplinary approach involving health care professionals as well as coaches and family members. Prevention of this condition is important to minimize complications of the female athlete triad. PMID:23016101

  7. An Athletic Arms Race

    ERIC Educational Resources Information Center

    Budig, Gene A.

    2007-01-01

    Myles Brand is a person of unquestioned integrity and high principle. As president of the National Collegiate Athletic Association (NCAA), he has been asked to fend off an unruly mob with a switch. In the present environment for collegiate sports, his chances for success are slight, at best. What Brand and the NCAA face today is a very real "arms…

  8. Eating Disorders among Athletes.

    ERIC Educational Resources Information Center

    Fairbanks, George

    1987-01-01

    Case examples are presented of typical pressures felt by aerobic dance instructors, cheerleaders and majorettes, and wrestlers to illustrate how they may become susceptible to eating disorders. Suggestions are presented for coaches, parents, and administrators in preventing or intervening in eating disorders among athletes. (CB)

  9. MUSCLE INJURIES IN ATHLETES

    PubMed Central

    Barroso, Guilherme Campos; Thiele, Edilson Schwansee

    2015-01-01

    This article had the aim of demonstrating the physiology, diagnosis and treatment of muscle injuries, focusing on athletes and their demands and expectations. Muscle injuries are among the most common complaints in orthopedic practice, occurring both among athletes and among non-athletes. These injuries present a challenge for specialists, due to the slow recovery, during which time athletes are unable to take part in training and competitions, and due to frequent sequelae and recurrences of the injuries. Most muscle injuries (between 10% and 55% of all injuries) occur during sports activities. The muscles most commonly affected are the ischiotibial, quadriceps and gastrocnemius. These muscles go across two joints and are more subject to acceleration and deceleration forces. The treatment for muscle injuries varies from conservative treatment to surgery. New procedures are being used, like the hyperbaric chamber and the use of growth factors. However, there is still a high rate of injury recurrence. Muscle injury continues to be a topic of much controversy. New treatments are being researched and developed, but prevention through muscle strengthening, stretching exercises and muscle balance continues to be the best “treatment”. PMID:27027021

  10. Gastrointestinal Bleeding in Athletes.

    ERIC Educational Resources Information Center

    Eichner, Edward R.

    1989-01-01

    Describes the scope and importance of gastrointestinal bleeding in runners and other athletes, discussing causes, sites, and implications of exercise-related bleeding. Practical tips to mitigate the problem, potentially more troublesome in women because of lower iron stores, are presented (e.g., gradual conditioning and avoidance of prerace…

  11. Nutrition and athletic performance

    MedlinePlus

    ... best for the first hour. Switching to an energy drink after the first hour will help you get ... in an unnatural way can have negative health effects. It is important to set realistic body weight goals. Young athletes who are trying to lose weight should work ...

  12. Drug abuse in athletes.

    PubMed

    Reardon, Claudia L; Creado, Shane

    2014-01-01

    Drug abuse occurs in all sports and at most levels of competition. Athletic life may lead to drug abuse for a number of reasons, including for performance enhancement, to self-treat otherwise untreated mental illness, and to deal with stressors, such as pressure to perform, injuries, physical pain, and retirement from sport. This review examines the history of doping in athletes, the effects of different classes of substances used for doping, side effects of doping, the role of anti-doping organizations, and treatment of affected athletes. Doping goes back to ancient times, prior to the development of organized sports. Performance-enhancing drugs have continued to evolve, with "advances" in doping strategies driven by improved drug testing detection methods and advances in scientific research that can lead to the discovery and use of substances that may later be banned. Many sports organizations have come to ban the use of performance-enhancing drugs and have very strict consequences for people caught using them. There is variable evidence for the performance-enhancing effects and side effects of the various substances that are used for doping. Drug abuse in athletes should be addressed with preventive measures, education, motivational interviewing, and, when indicated, pharmacologic interventions. PMID:25187752

  13. Change and Athletic Training

    ERIC Educational Resources Information Center

    Ray, Richard

    2006-01-01

    Dr. R. Richard Ray, Jr. is a Professor and Chair of Kinesiology at Hope College in Holland, Michigan. Since 1982 he has served as the Program Director for the Athletic Training Education Program at Hope College. Dr. Ray is the author of several books and over 40 articles. In this article he begins by laying a foundation for the reasons why change…

  14. Abuse of Anabolic Steroids and Their Precursors by Adolescent Amateur Athletes. Hearing before the Senate Caucus on International Narcotics Control, One Hundred Eighth Congress, Second Session (July 13, 2004). Senate Hearing 108-814

    ERIC Educational Resources Information Center

    US Senate, 2005

    2005-01-01

    For more than two decades, the use of steroids by professional athletes has been widely reported. Indictments against executive officers of a San Francisco area nutritional supplements lab--and these indictments were Federal steroid distribution charges--have brought even more attention to the use of steroids. Recently, accusations of world-class…

  15. Long term consequences of the female athlete triad.

    PubMed

    Thein-Nissenbaum, Jill

    2013-06-01

    In the past 40 years, female sports participation, particularly at the high school level, has significantly increased. Physical activity in females has numerous positive benefits, including improved body image and overall health. Unfortunately, a select population of exercising females may experience symptoms related to the female athlete triad, which refers to the interrelatedness of energy availability, menstrual function, and bone mineral density. Clinically, these conditions can manifest as disordered eating behaviors, menstrual irregularity, and stress fractures. Triad symptoms are distributed along a spectrum between optimal health and disease; all of the components of the triad may not be affected simultaneously. The female athlete triad was first identified in 1992. Since that time, a vast amount of research related to the identification, management and prevention of this condition has been published. More recently, research related to the long term effects of triad components has come into light. Women who were diagnosed with female athlete triad syndrome as adolescents and young adults in the 1990s are now in their 30s and 40s; negative long term effects of the female athlete triad, such as low bone mineral density, are now starting to manifest. Women of all ages should be assessed for triad components during routine annual physical examinations; appropriate measures to treat any current triad components should be implemented. In addition, women in their 30s, 40s and early 50s should be screened for a history of the female athlete triad. Multidisciplinary management of these conditions is strongly recommended. PMID:23541905

  16. Does improved decision-making ability reduce the physiological demands of game-based activities in field sport athletes?

    PubMed

    Gabbett, Tim J; Carius, Josh; Mulvey, Mike

    2008-11-01

    This study investigated the effects of video-based perceptual training on pattern recognition and pattern prediction ability in elite field sport athletes and determined whether enhanced perceptual skills influenced the physiological demands of game-based activities. Sixteen elite women soccer players (mean +/- SD age, 18.3 +/- 2.8 years) were allocated to either a video-based perceptual training group (N = 8) or a control group (N = 8). The video-based perceptual training group watched video footage of international women's soccer matches. Twelve training sessions, each 15 minutes in duration, were conducted during a 4-week period. Players performed assessments of speed (5-, 10-, and 20-m sprint), repeated-sprint ability (6 x 20-m sprints, with active recovery on a 15-second cycle), estimated maximal aerobic power (V O2 max, multistage fitness test), and a game-specific video-based perceptual test of pattern recognition and pattern prediction before and after the 4 weeks of video-based perceptual training. The on-field assessments included time-motion analysis completed on all players during a standardized 45-minute small-sided training game, and assessments of passing, shooting, and dribbling decision-making ability. No significant changes were detected in speed, repeated-sprint ability, or estimated V O2 max during the training period. However, video-based perceptual training improved decision accuracy and reduced the number of recall errors, indicating improved game awareness and decision-making ability. Importantly, the improvements in pattern recognition and prediction ability transferred to on-field improvements in passing, shooting, and dribbling decision-making skills. No differences were detected between groups for the time spent standing, walking, jogging, striding, and sprinting during the small-sided training game. These findings demonstrate that video-based perceptual training can be used effectively to enhance the decision-making ability of field

  17. Motion analyses of adolescent rugby union players: a comparison of training and game demands.

    PubMed

    Hartwig, Timothy B; Naughton, Geraldine; Searl, John

    2011-04-01

    This research described the physiological demands of participation in adolescent rugby union including positional differences and the degree to which training practices replicate game demands. Between 2003 and 2008, 118 male adolescent rugby players aged 14 to 18 years were recruited from 10 teams representing 3 levels of adolescent rugby. Time-motion analyses using global positioning satellite tracking devices (SPI10; GPSports Systems Pty Ltd 2003) and computer-based tracking software (Trak Performance; Sports Tec Pty Ltd) applied to video footage determined player movement patterns 161 times during rugby training sessions and 53 times during rugby games. Compared with rugby training, rugby games were consistently characterized by more time spent jogging (14 vs. 8%), striding (3.2 vs. 1.3%), and sprinting (1.3 vs. 0.1%) (p < 0.001). Players also covered greater distances (4000 ± 500 vs. 2710 ± 770 m) and performed more sprints (21.8 vs. 1) during games compared with training (p < 0.001). The average sprint duration of 2 seconds was similar in games and training; however, the frequency of sprint efforts in training sessions was low (1 per hour). A major finding of this study is the disparity between physical game demands and on-field rugby training practices in adolescent players determined using time-motion analyses. Sprint pattern differences between games and training in particular could have important implications for player performance during competition. Results of this study should assist in the development of game-specific training sessions and drills that provide the kinds of physically demanding experiences observed in games. Additionally, coaches could assist in the management of adolescent players' participation loads by increasing the intensity and specificity and decreasing the volume of training. PMID:20647941

  18. The Role of the Faculty Athletics Representative.

    ERIC Educational Resources Information Center

    Cooper, Arthur W.

    1992-01-01

    The faculty athletics representative plays an important role in the athletic-academic relationship. This responsibility includes certifying student-athlete eligibility, reporting academic data as required, evaluating athlete-applicant qualifications and abilities, regular evaluation of athlete performance, and participation in evaluation of…

  19. Specific Measurement of Tethered Running Kinetics and its Relationship to Repeated Sprint Ability

    PubMed Central

    Sousa, Filipe; dos Reis, Ivan; Ribeiro, Luiz; Martins, Luiz; Gobatto, Claudio

    2015-01-01

    Repeated sprint ability has been widely studied by researchers, however, analysis of the relationship between most kinetic variables and the effect of fatigue is still an ongoing process. To search for the best biomechanical parameter to evaluate repeated sprint ability, several kinetic variables were measured in a tethered field running test and compared regarding their sensitivity to fatigue and correlation with time trials in a free running condition. Nine male sprint runners (best average times: 100 m = 10.45 ± 0.07 s; 200 m = 21.36 ± 0.17 s; 400 m = 47.35 ± 1.09 s) completed two test sessions on a synthetic track. Each session consisted of six 35 m sprints interspersed by 10 s rest under tethered field running or free running conditions. Force, power, work, an impulse and a rate of force development were all directly measured using the sensors of a new tethered running apparatus, and a one-way ANOVA with Scheffé post-hoc test used to verify differences between sprints (p < 0.05). Pearson product-moment correlation measured the relationship between mechanical variables and free running performance. A total impulse, the rate of force development and maximum force did not show significant differences for most sprints. These three variables presented low to moderate correlations with free running performance (r between 0.01 and −0.35). Maximum and mean power presented the strongest correlations with free running performance (r = −0.71 and −0.76, respectively; p < 0.001), followed by mean force (r = −0.61; p < 0.001) and total work (r = −0.50; p < 0.001). It was concluded that under a severe work-to-rest ratio condition, power variables were better suited to evaluating repeated sprint ability than the other studied variables. PMID:26839625

  20. Effects of hamstring-emphasized neuromuscular training on strength and sprinting mechanics in football players.

    PubMed

    Mendiguchia, J; Martinez-Ruiz, E; Morin, J B; Samozino, P; Edouard, P; Alcaraz, P E; Esparza-Ros, F; Mendez-Villanueva, A

    2015-12-01

    The objective of this study was to examine the effects of a neuromuscular training program combining eccentric hamstring muscle strength, plyometrics, and free/resisted sprinting exercises on knee extensor/flexor muscle strength, sprinting performance, and horizontal mechanical properties of sprint running in football (soccer) players. Sixty footballers were randomly assigned to an experimental group (EG) or a control group (CG). Twenty-seven players completed the EG and 24 players the CG. Both groups performed regular football training while the EG performed also a neuromuscular training during a 7-week period. The EG showed a small increases in concentric quadriceps strength (ES = 0.38/0.58), a moderate to large increase in concentric (ES = 0.70/0.74) and eccentric (ES = 0.66/0.87) hamstring strength, and a small improvement in 5-m sprint performance (ES = 0.32). By contrast, the CG presented lower magnitude changes in quadriceps (ES = 0.04/0.29) and hamstring (ES = 0.27/0.34) concentric muscle strength and no changes in hamstring eccentric muscle strength (ES = -0.02/0.11). Thus, in contrast to the CG (ES = -0.27/0.14), the EG showed an almost certain increase in the hamstring/quadriceps strength functional ratio (ES = 0.32/0.75). Moreover, the CG showed small magnitude impairments in sprinting performance (ES = -0.35/-0.11). Horizontal mechanical properties of sprint running remained typically unchanged in both groups. These results indicate that a neuromuscular training program can induce positive hamstring strength and maintain sprinting performance, which might help in preventing hamstring strains in football players. PMID:25556888

  1. Nitrate Intake Promotes Shift in Muscle Fiber Type Composition during Sprint Interval Training in Hypoxia

    PubMed Central

    De Smet, Stefan; Van Thienen, Ruud; Deldicque, Louise; James, Ruth; Sale, Craig; Bishop, David J.; Hespel, Peter

    2016-01-01

    Purpose: We investigated the effect of sprint interval training (SIT) in normoxia, vs. SIT in hypoxia alone or in conjunction with oral nitrate intake, on buffering capacity of homogenized muscle (βhm) and fiber type distribution, as well as on sprint and endurance performance. Methods: Twenty-seven moderately-trained participants were allocated to one of three experimental groups: SIT in normoxia (20.9% FiO2) + placebo (N), SIT in hypoxia (15% FiO2) + placebo (H), or SIT in hypoxia + nitrate supplementation (HN). All participated in 5 weeks of SIT on a cycle ergometer (30-s sprints interspersed by 4.5 min recovery-intervals, 3 weekly sessions, 4–6 sprints per session). Nitrate (6.45 mmol NaNO3) or placebo capsules were administered 3 h before each session. Before and after SIT participants performed an incremental VO2max-test, a 30-min simulated cycling time-trial, as well as a 30-s cycling sprint test. Muscle biopsies were taken from m. vastus lateralis. Results: SIT decreased the proportion of type IIx muscle fibers in all groups (P < 0.05). The relative number of type IIa fibers increased (P < 0.05) in HN (P < 0.05 vs. H), but not in the other groups. SIT had no significant effect on βhm. Compared with H, SIT tended to enhance 30-s sprint performance more in HN than in H (P = 0.085). VO2max and 30-min time-trial performance increased in all groups to a similar extent. Conclusion: SIT in hypoxia combined with nitrate supplementation increases the proportion of type IIa fibers in muscle, which may be associated with enhanced performance in short maximal exercise. Compared with normoxic training, hypoxic SIT does not alter βhm or endurance and sprinting exercise performance. PMID:27378942

  2. Visual- spatial capacity: gender and sport differences in young volleyball and tennis athletes and non-athletes

    PubMed Central

    2014-01-01

    Background In the general population visual-spatial ability is better in males, due to the influence of biological and socio-cultural factors. We know that sport activity improves motor skills. The aim of this work is to determine if these gender differences exist in young athletes. The orientation test described by Terzi and standardized by Cesaroni, used to measure spatial ability, was carried out on 60 volleyball or 60 tennis athletes as well as on 60 non-sporting subjects. Results The data analysis revealed a worse performance for non-athletes in comparison with athletes in both components of test (p < 0.0001; p = 0.04), with no differences between the volleyball and tennis groups. As far as gender comparison is concerned, as expected in the non- sport group the males presented better values (p < 0.001; p = 0.006). However in both sports groups there weren’t any gender differences in either part of the test (p = 0.18; p = 0.056). Conclusions These results confirm that during athletic preparation in volleyball and tennis the specific training is able to develop spatial ability. Besides, boys and girls have similar performance demands and training experience. It appears that this specific training could be responsible for modifying gender differences in performance of spatial ability during adolescence. PMID:24447526

  3. Prediction Versus Reality: The Use of Mathematical Models to Predict Elite Performance in Swimming and Athletics at the Olympic Games

    PubMed Central

    Heazlewood, Timothy

    2006-01-01

    A number of studies have attempted to predict future Olympic performances in athletics and swimming based on trends displayed in previous Olympic Games. Some have utilised linear models to plot and predict change, whereas others have utilised multiple curve estimation methods based on inverse, sigmoidal, quadratic, cubic, compound, logistic, growth and exponential functions. The non linear models displayed closer fits to the actual data and were used to predict performance changes 10’s, 100’s and 1000’s of years into the future. Some models predicted that in some events male and female times and distances would crossover and females would eventually display superior performance to males. Predictions using mathematical models based on pre-1996 athletics and pre-1998 swimming performances were evaluated based on how closely they predicted sprints and jumps, and freestyle swimming performances for both male and females at the 2000 and 2004 Olympic Games. The analyses revealed predictions were closer for the shorter swimming events where men’s 50m and women’s 50m and 100m actual times were almost identical to predicted times. For both men and women, as the swim distances increased the accuracy of the predictive model decreased, where predicted times were 4.5-7% faster than actual times achieved. The real trends in some events currently displaying performance declines were not foreseen by the mathematical models, which predicted consistent improvements across all athletic and swimming events selected for in this study. Key Points Prediction of future Olympic performance based on previous performance trends. Application of non-linear mathematical equations resulting in better fitting models. Application of mathematical predictive models to the Olympic sports of athletics and swimming. Accuracy of mathematical models in predicting sprint events in running and swimming. A research approach to predict future Olympic performance and set future performance standards

  4. National Athletic Trainers' Association Position Statement: Fluid Replacement for Athletes

    PubMed Central

    Casa, Douglas J.; Armstrong, Lawrence E.; Hillman, Susan K.; Montain, Scott J.; Reiff, Ralph V.; Rich, Brent S. E.; Roberts, William O.; Stone, Jennifer A.

    2000-01-01

    Objective: To present recommendations to optimize the fluid-replacement practices of athletes. Background: Dehydration can compromise athletic performance and increase the risk of exertional heat injury. Athletes do not voluntarily drink sufficient water to prevent dehydration during physical activity. Drinking behavior can be modified by education, increasing accessibility, and optimizing palatability. However, excessive overdrinking should be avoided because it can also compromise physical performance and health. We provide practical recommendations regarding fluid replacement for athletes. Recommendations: Educate athletes regarding the risks of dehydration and overhydration on health and physical performance. Work with individual athletes to develop fluid-replacement practices that optimize hydration status before, during, and after competition. Imagesp224-a PMID:16558633

  5. Effects of in-season short-term plyometric training program on leg power, jump- and sprint performance of soccer players.

    PubMed

    Chelly, Mohamed Souhaiel; Ghenem, Mohamed Ali; Abid, Khalil; Hermassi, Souhail; Tabka, Zouhair; Shephard, Roy J

    2010-10-01

    Our hypothesis was that the addition of an 8-week lower limb plyometric training program (hurdle and depth jumping) to normal in-season conditioning would enhance measures of competitive potential (peak power output [PP], jump force, jump height, and lower limb muscle volume) in junior soccer players. The subjects (23 men, age 19 ± 0.7 years, body mass 70.5 ± 4.7 kg, height 1.75 ± 0.06 m, body fat 14.7 ± 2.6%) were randomly assigned to a control (normal training) group (Gc; n = 11) and an experimental group (Gex, n = 12) that also performed biweekly plyometric training. A force-velocity ergometer test determined PP. Characteristics of the squat jump (SJ) and the countermovement jump (CMJ) (jump height, maximal force and velocity before take-off, and average power) were determined by force platform. Video-camera kinematic analyses over a 40-m sprint yielded running velocities for the first step (VS), the first 5 m (V5m) and between 35 and 40 m (Vmax). Leg muscle volume was estimated using a standard anthropometric kit. Gex showed gains relative to controls in PP (p < 0.01); SJ (height p < 0.01; velocity p < 0.001), CMJ (height p < 0.001; velocity p < 0.001, average power p < 0.01) and all sprint velocities (p < 0.001 for V5m and Vmax, p < 0.01 for VS). There was also a significant increase (p < 0.05) in thigh muscle volume, but leg muscle volume and mean thigh cross-sectional area remain unchanged. We conclude that biweekly plyometric training of junior soccer players (including adapted hurdle and depth jumps) improved important components of athletic performance relative to standard in-season training. Accordingly, such exercises are highly recommended as part of an annual soccer training program. PMID:20844458

  6. Radiographic Evidence of Femoroacetabular Impingement in Athletes With Athletic Pubalgia

    PubMed Central

    Economopoulos, Kostas J.; Milewski, Matthew D.; Hanks, John B.; Hart, Joseph M.; Diduch, David R.

    2014-01-01

    Background: Two of the most common causes of groin pain in athletes are femoroacetabular impingement (FAI) and athletic pubalgia. An association between the 2 is apparent, but the prevalence of radiographic signs of FAI in patients undergoing athletic pubalgia surgery remains unknown. The purpose of this study was to determine the prevalence of radiologic signs of FAI in patients with athletic pubalgia. Hypothesis: We hypothesized that patients with athletic pubalgia would have a high prevalence of underlying FAI. Study Design: Case series. Level of Evidence: Level 4. Methods: A retrospective review of all patients evaluated at our institution with athletic pubalgia who underwent surgical treatment (ie, for sports hernia) from 1999 to 2011 was performed. The radiographs of patients with athletic pubalgia were reviewed for radiographic signs of FAI. Alpha angles were measured using frog-leg lateral radiographs. Pincer lesions were identified by measuring the lateral center-edge angle and identifying the presence of a “crossover” sign on anteroposterior radiographs. Phone follow-up was performed 2 years or more after the initial sports hernia surgery to evaluate recurrent symptoms. Results: Forty-three patients underwent 56 athletic pubalgia surgeries. Radiographic evidence of FAI was identified in at least 1 hip in 37 of 43 patients (86%). Cam lesions were identified in 83.7% of the population; the alpha angle averaged 66.7° ± 17.9° for all hips. Pincer lesions were present in 28% of the hips. Eight patients had recurrent groin pain, 3 patients had revision athletic pubalgia surgery, and 1 had hip arthroscopy. Conclusion: The study demonstrates a high prevalence of radiographic FAI in patients with athletic pubalgia. Clinical Relevance: Underlying FAI may be a cause of continued groin pain after athletic pubalgia surgery. Patients with athletic pubalgia should be evaluated closely for FAI. PMID:24587869

  7. Jump Kinetic Determinants of Sprint Acceleration Performance from Starting Blocks in Male Sprinters

    PubMed Central

    Maulder, Peter S.; Bradshaw, Elizabeth J.; Keogh, Justin

    2006-01-01

    The purpose of this research was to identify the jump kinetic determinants of sprint acceleration performance from a block start. Ten male (mean ± SD: age 20 ± 3 years; height 1.82 ± 0.06 m; weight 76.7 ± 7.9 kg; 100 m personal best: 10.87 + 0.36 s {10.37 - 11.42}) track sprinters at a national and regional competitive level performed 10 m sprints from a block start. Anthropometric dimensions along with squat jump (SJ), countermovement jump (CMJ), continuous straight legged jump (SLJ), single leg hop for distance, and single leg triple hop for distance measures of power were also tested. Stepwise multiple regression analysis identified CMJ average power (W/kg) as a predictor of 10 m sprint performance from a block start (r = 0.79, r2 = 0.63, p<0.01, SEE = 0.04 (s), %SEE = 2.0). Pearson correlation analysis revealed CMJ force and power (r = -0.70 to -0.79; p = 0.011 - 0.035) and SJ power (r = -0.72 to -0.73; p = 0.026 - 0.028) generating capabilities to be strongly related to sprint performance. Further linear regression analysis predicted an increase in CMJ average and peak take-off power of 1 W/kg (3% & 1.5% respectively) to both result in a decrease of 0.01 s (0.5%) in 10 m sprint performance. Further, an increase in SJ average and peak take-off power of 1 W/kg (3.5% & 1.5% respectively) was predicted to result in a 0.01 s (0.5%) reduction in 10 m sprint time. The results of this study seem to suggest that the ability to generate power both elastically during a CMJ and concentrically during a SJ to be good indicators of predicting sprint performance over 10 m from a block start. Key Points The relative explosive ability of the hip and knee extensors during a countermovement jump can predict 10 m sprint performance from a block start. The relative power outputs of male competitive sprinters during a squat jump can predict 10 m sprint performance from a block start. PMID:24260010

  8. Injury Rehabilitation Overadherence: Preliminary Scale Validation and Relationships With Athletic Identity and Self-Presentation Concerns

    PubMed Central

    Podlog, Leslie; Gao, Zan; Kenow, Laura; Kleinert, Jens; Granquist, Megan; Newton, Maria; Hannon, James

    2013-01-01

    Context: Evidence suggests that nonadherence to rehabilitation protocols may be associated with worse clinical and functional rehabilitation outcomes. Recently, it has been recognized that nonadherence may not only reflect a lack of rehabilitation engagement but that some athletes may “overadhere” to their injury-rehabilitation regimen or risk a premature return to sport. Presently, no measure of overadherence exists, and correlates of overadherence and risking a premature return to sport remain uncertain. Objective: To provide initial validation of a novel injury-rehabilitation overadherence measure (study 1) and to examine correlates of overadherence and risking a premature return to sport (study 2). Design: Cross-sectional study. Setting: High school athletes (study 1) and collegiate athletes (study 2). Patients or Other Participants: In study 1, 118 currently injured US adolescent athletes competing in a range of high school sports participated. In study 2, 105 currently injured collegiate athletes (National Collegiate Athletic Association Divisions I–III) volunteered. Main Outcome Measure(s): The Rehabilitation Overadherence Questionnaire was a novel instrument developed to assess injured athletes' tendency toward overadherence behaviors and beliefs. We used an adapted version of the Injury Psychological Readiness to Return to Sport Scale to assess the tendency to risk a premature return to sport. Results: In study 1, the construct validity of the overadherence measure was supported using principal axis factoring. Moreover, bivariate correlation and regression analyses indicated that self-presentation concerns and athletic identity were positive predictors of adolescent rehabilitation overadherence and a premature return to sport. Study 2 provided support for the 2-factor structure of the overadherence measure found in study 1 via confirmatory factor analysis. Further support for the relationship among self-presentation concerns, athletic identity, and

  9. Green Tea, Intermittent Sprinting Exercise, and Fat Oxidation.

    PubMed

    Gahreman, Daniel; Wang, Rose; Boutcher, Yati; Boutcher, Stephen

    2015-07-01

    Fat oxidation has been shown to increase after short term green tea extract (GTE) ingestion and after one bout of intermittent sprinting exercise (ISE). Whether combining the two will result in greater fat oxidation after ISE is undetermined. The aim of the current study was to investigate the combined effect of short term GTE and a single session of ISE upon post-exercise fat oxidation. Fourteen women consumed three GTE or placebo capsules the day before and one capsule 90 min before a 20-min ISE cycling protocol followed by 1 h of resting recovery. Fat oxidation was calculated using indirect calorimetry. There was a significant increase in fat oxidation post-exercise compared to at rest in the placebo condition (p < 0.01). After GTE ingestion, however, at rest and post-exercise, fat oxidation was significantly greater (p < 0.05) than that after placebo. Plasma glycerol levels at rest and 15 min during post-exercise were significantly higher (p < 0.05) after GTE consumption compared to placebo. Compared to placebo, plasma catecholamines increased significantly after GTE consumption and 20 min after ISE (p < 0.05). Acute GTE ingestion significantly increased fat oxidation under resting and post-exercise conditions when compared to placebo. PMID:26184298

  10. Green Tea, Intermittent Sprinting Exercise, and Fat Oxidation

    PubMed Central

    Gahreman, Daniel; Wang, Rose; Boutcher, Yati; Boutcher, Stephen

    2015-01-01

    Fat oxidation has been shown to increase after short term green tea extract (GTE) ingestion and after one bout of intermittent sprinting exercise (ISE). Whether combining the two will result in greater fat oxidation after ISE is undetermined. The aim of the current study was to investigate the combined effect of short term GTE and a single session of ISE upon post-exercise fat oxidation. Fourteen women consumed three GTE or placebo capsules the day before and one capsule 90 min before a 20-min ISE cycling protocol followed by 1 h of resting recovery. Fat oxidation was calculated using indirect calorimetry. There was a significant increase in fat oxidation post-exercise compared to at rest in the placebo condition (p < 0.01). After GTE ingestion, however, at rest and post-exercise, fat oxidation was significantly greater (p < 0.05) than that after placebo. Plasma glycerol levels at rest and 15 min during post-exercise were significantly higher (p < 0.05) after GTE consumption compared to placebo. Compared to placebo, plasma catecholamines increased significantly after GTE consumption and 20 min after ISE (p < 0.05). Acute GTE ingestion significantly increased fat oxidation under resting and post-exercise conditions when compared to placebo. PMID:26184298

  11. The effects of traditional and enforced stopping speed and agility training on multidirectional speed and athletic function.

    PubMed

    Lockie, Robert G; Schultz, Adrian B; Callaghan, Samuel J; Jeffriess, Matthew D

    2014-06-01

    This study investigated the effects of a traditional speed and agility training program (TSA) and an enforced stopping program emphasizing deceleration (ESSA). Twenty college-aged team sport athletes (16 males, 4 females) were allocated into the training groups. Pretesting and posttesting included: 0-10, 0-20, 0-40 m sprint intervals, change-of-direction, and acceleration test (CODAT), T-test (multidirectional speed); vertical, standing broad, lateral, and drop jumps, medicine ball throw (power); Star Excursion Balance Test (posteromedial, medial, anteromedial reaches; dynamic stability); and concentric (240° · s(-1)) and eccentric (30° · s(-1)) knee extensor and flexor isokinetic testing (unilateral strength). Both groups completed a 6-week speed and agility program. The ESSA subjects decelerated to a stop within a specified distance in each drill. A repeated measures analysis of variance determined significant (p ≤ 0.05) within- and between-group changes. Effect sizes (Cohen's d) were calculated. The TSA group improved all speed tests (d = 0.29-0.96), and most power tests (d = 0.57-1.10). The ESSA group improved the 40-m sprint, CODAT, T-test, and most power tests (d = 0.46-1.31) but did not significantly decrease 0-10 and 0-20 m times. The TSA group increased posteromedial and medial excursions (d = 0.97-1.89); the ESSA group increased medial excursions (d = 0.99-1.09). The ESSA group increased concentric knee extensor and flexor strength, but also increased between-leg knee flexor strength differences (d = 0.50-1.39). The loading associated with stopping can increase unilateral strength. Coaches should ensure deceleration drills allow for appropriate sprint distances before stopping, and athletes do not favor 1 leg for stopping after deceleration. PMID:24169474

  12. Four Weeks of Sprint Interval Training Improves 5-km Run Performance.

    PubMed

    Denham, Joshua; Feros, Simon A; OʼBrien, Brendan J

    2015-08-01

    Sprint interval training (SIT) rapidly improves cardiorespiratory fitness but demands less training time and volume than traditional endurance training. Although the health and fitness benefits caused by SIT have received considerable research focus, the effect of short-term SIT on 5-km run performance is unknown. Thirty healthy untrained participants (aged 18-25 years) were allocated to a control (n = 10) or a SIT (n = 20) group. Sprint interval training involved 3-8 sprints at maximal intensity, 3 times a week for 4 weeks. Sprints were progressed to 8 by the 12th session. All participants completed a 5-km time trial on a public running track and an incremental treadmill test in an exercise physiology laboratory to determine 5-km run performance and maximum oxygen uptake, respectively, before and after the 4-week intervention. Relative to the controls, sprint interval-trained participants improved 5-km run performance by 4.5% (p < 0.001), and this was accompanied by improvements in absolute and relative maximum oxygen uptake (4.9%, p = 0.04 and 4.5%, p = 0.045, respectively). Therefore, short-term SIT significantly improves 5-km run performance in untrained young men. We believe that SIT is a time-efficient means of improving cardiorespiratory fitness and 5-km endurance performance. PMID:25647646

  13. SPRINT: a brief global assessment of post-traumatic stress disorder.

    PubMed

    Connor, K M; Davidson, J R

    2001-09-01

    This report describes the reliability, validity, treatment sensitivity, diagnostic performance and normative values for the Short Post-Traumatic Stress Disorder (PTSD) Rating Interview (SPRINT), a brief, global assessment for PTSD. The SPRINT was administered to subjects participating in a clinical trial of PTSD and in a population survey assessing PTSD prevalence. The 8-item SPRINT includes questions assessing the core symptoms of PTSD, as well as related aspects of somatic malaise, stress vulnerability and functional impairment. Validity was assessed against the MINI structured interview, the Davidson Trauma Scale, Treatment Outcome for PTSD Scale, Connor-Davidson Resilience Scale, Sheehan Stress Vulnerability Scale, Sheehan Disability Scale and Clinical Global Impressions of Severity and Improvement Scales. Good test-retest reliability, internal consistency, convergent and divergent validity were obtained. The SPRINT was responsive to symptom change over time and correlated with comparable PTSD symptom measures. In victims of trauma, a score of 14-17 was associated with 96% diagnostic accuracy, whereas in those with PTSD, highest efficiency corresponded to a range of 11-13. The SPRINT demonstrates solid psychometric properties and can serve as a reliable, valid and homogeneous measure of PTSD illness severity and of global improvement. PMID:11552771

  14. Relationship between the peak time of hamstring stretch and activation during sprinting.

    PubMed

    Higashihara, Ayako; Nagano, Yasuharu; Ono, Takashi; Fukubayashi, Toru

    2016-01-01

    The purpose of this study was to investigate the time series relationships between the peak musculotendon length and electromyography (EMG) activation during overground sprinting to clarify the risk of muscle strain injury incidence in each hamstring muscle. Full-body kinematics and EMG of the right biceps femoris long head (BFlh) and semitendinosus (ST) muscles were recorded in 13 male sprinters during overground sprinting at maximum effort. The hamstring musculotendon lengths during sprinting were computed using a three-dimensional musculoskeletal model. The time of the peak musculotendon length, in terms of the percentage of the running gait cycle, was measured and compared with that of the peak EMG activity. The maximum length of the hamstring muscles was noted during the late swing phase of sprinting. The peak musculotendon length was synchronous with the peak EMG activation in the BFlh muscle, while the time of peak musculotendon length in the ST muscle occurred significantly later than the peak level of EMG activation (p < 0.05). These results suggest that the BFlh muscle is exposed to an instantaneous high tensile force during the late swing phase of sprinting, indicating a higher risk for muscle strain injury. PMID:25360992

  15. Sprint Acceleration Mechanics: The Major Role of Hamstrings in Horizontal Force Production

    PubMed Central

    Morin, Jean-Benoît; Gimenez, Philippe; Edouard, Pascal; Arnal, Pierrick; Jiménez-Reyes, Pedro; Samozino, Pierre; Brughelli, Matt; Mendiguchia, Jurdan

    2015-01-01

    Recent literature supports the importance of horizontal ground reaction force (GRF) production for sprint acceleration performance. Modeling and clinical studies have shown that the hip extensors are very likely contributors to sprint acceleration performance. We experimentally tested the role of the hip extensors in horizontal GRF production during short, maximal, treadmill sprint accelerations. Torque capabilities of the knee and hip extensors and flexors were assessed using an isokinetic dynamometer in 14 males familiar with sprint running. Then, during 6-s sprints on an instrumented motorized treadmill, horizontal and vertical GRF were synchronized with electromyographic (EMG) activity of the vastus lateralis, rectus femoris, biceps femoris, and gluteus maximus averaged over the first half of support, entire support, entire swing and end-of-swing phases. No significant correlations were found between isokinetic or EMG variables and horizontal GRF. Multiple linear regression analysis showed a significant relationship (P = 0.024) between horizontal GRF and the combination of biceps femoris EMG activity during the end of the swing and the knee flexors eccentric peak torque. In conclusion, subjects who produced the greatest amount of horizontal force were both able to highly activate their hamstring muscles just before ground contact and present high eccentric hamstring peak torque capability. PMID:26733889

  16. BP Targets in Hypertension: What Should We Do Now That SPRINT Is Out?

    PubMed

    Bhatt, Hemal; Ghazi, Lama; Calhoun, David; Oparil, Suzanne

    2016-10-01

    Systolic blood pressure (SBP) is an important predictor of cardiovascular disease (CVD) outcomes. Lowering SBP has been shown to reduce CVD morbidity and mortality, but the optimal SBP target continues to be a topic of intense debate. The Systolic Blood Pressure Intervention Trial (SPRINT) reported a significantly lower risk for CVD outcomes and all-cause mortality by targeting SBP <120 mmHg compared with <140 mmHg in a population of hypertensive persons at high CV risk. In this review, we discuss the strengths, limitations, and generalizability of SPRINT findings to other hypertensive populations that were excluded from the trial, including those with diabetes or prior stroke, <50 years old, and at lower CVD risk. We will focus on the implications of SPRINT findings for appropriate BP targets in high-risk groups of hypertensive persons, including the elderly and those with chronic kidney disease (CKD). We will also address the cost-effectiveness of intensive BP treatment as implemented in SPRINT and the implications of SPRINT for health care policy and future BP guidelines. PMID:27566331

  17. Ground Reaction Force and Cadence during Stationary Running Sprint in Water and on Land.

    PubMed

    Fontana, H de Brito; Ruschel, C; Haupenthal, A; Hubert, M; Roesler, H

    2015-06-01

    This study was aimed at analyzing the cadence (Cadmax) and the peak vertical ground reaction force (Fymax) during stationary running sprint on dry land and at hip and chest level of water immersion. We hypothesized that both Fymax and Cadmax depend on the level of immersion and that differences in Cadmax between immersions do not affect Fymax during stationary sprint. 32 subjects performed the exercise at maximum cadence at each immersion level and data were collected with force plates. The results show that Cadmax and Fymax decrease 17 and 58% from dry land to chest immersion respectively, with no effect of cadence on Fymax. While previous studies have shown similar neuromuscular responses between aquatic and on land stationary sprint, our results emphasize the differences in Fymax between environments and levels of immersion. Additionally, the characteristics of this exercise permit maximum movement speed in water to be close to the maximum speed on dry land. The valuable combination of reduced risk of orthopedic trauma with similar neuromuscular responses is provided by the stationary sprint exercise in water. The results of this study support the rationale behind the prescription of stationary sprinting in sports training sessions as well as rehabilitation programs. PMID:25700098

  18. Administering the School's Athletic Training Program.

    ERIC Educational Resources Information Center

    Butler, Paul S.

    1981-01-01

    Discusses the role of each member of a secondary school's athletic health care team, including the principal, athletic director, team physician, school nurse, coach or physical educator, and professional and student athletic trainers. (WD)

  19. MRSA Prevention Information and Advice for Athletes

    MedlinePlus

    ... What to do If You Think You Have MRSA Tell your parent, coach, athletic trainer, school nurse, ... MRSA in athletic facilities... Top of Page Why MRSA is Spread among Athletes MRSA might spread easily ...

  20. Nutrition and the Athlete

    PubMed Central

    Bullard, J. A.

    1978-01-01

    The importance of good nutrition cannot be over emphasized for both the athlete and the non-athlete. The difference is essentially in the number of calories. Both need a well balanced diet, normally taken as three meals a day. Modifications on the day of participation require planning as well as understanding. Many myths have developed from a false impression that some advantage will be gained over an opponent or that performance will be enhanced. Scientific evidence does not support these claims. The physician should be aware of the recommendations contained in the Canadian Food Guide for the basic diet. He should also be prepared to discuss variations in dietary habits which have entered the sports scene. PMID:20469286

  1. Groin pain in athletes.

    PubMed

    Weber, M-A; Rehnitz, C; Ott, H; Streich, N

    2013-12-01

    Groin pain in athletes is one of the most difficult to treat clinical entities in sports medicine. The reasons are the amount of differential diagnoses, complexity of pathophysiologic causes and the long time of limited participation in sport. In order to maximize efficient treatment, thorough diagnostics and a clear therapeutic regimen are crucial. To succeed with this issue, a close cooperation between physicians and radiologists is mandatory. MRI is gold standard in the diagnostic work-up of the principal differential diagnoses, such as muscle tears, avulsion injuries, stress fractures, tears of acetabular labrum, and osteitis pubis. The article gives a comprehensive overview of the special anatomy and biomechanics of the pubic region and of typical MRI findings in athletes with groin pain. The use of dedicated imaging protocols is also discussed. PMID:23893752

  2. [Groin pain in athletes].

    PubMed

    Sanders, Rick J M; Kokshoorn, Arjan P J; Kolkman, Karel A; van der Wal, Wybren A; van Loon, Corné J M

    2014-01-01

    Groin pain in young athletes is a common problem, accounting for significant downtime in sports participation. It can be difficult to make the correct diagnosis as groin pain has a wide differential diagnosis, which encompasses acute as well as chronic causative factors. In this article this is illustrated by presenting three cases of patients who attended our hospital. In all three cases the main complaint was sports-related groin pain, and the patients presented with very similar symptoms. However, after further investigation the patients were diagnosed with three very different types of injury: sportsman's hernia; hip labral tear; and pubic osteitis. This emphasises the need for every general practitioner and medical specialist to understand that there is a wide differential diagnosis for groin pain in athletes, in order to be able to implement specific therapy targeting the actual cause of groin pain. PMID:25315329

  3. The Running Athlete

    PubMed Central

    Henning, P. Troy

    2014-01-01

    Context: Pelvic stress fractures, osteitis pubis, and snapping hip syndrome account for a portion of the overuse injuries that can occur in the running athlete. Evidence Acquisition: PubMed searches were performed for each entity using the following keywords: snapping hip syndrome, coxa sultans, pelvic stress fracture, and osteitis pubis from 2008 to 2013. Topic reviews, case reports, case series, and randomized trials were included for review. Study Design: Clinical review. Level of Evidence: Level 4. Results: Collectively, 188 articles were identified. Of these, 58 were included in this review. Conclusion: Based on the available evidence, the majority of these overuse injuries can be managed non-operatively. Primary treatment should include removal from offending activity, normalizing regional muscle strength/length imbalances and nutritional deficiencies, and mitigating training errors through proper education of the athlete and training staff. Strength of Recommendation Taxonomy: C PMID:24587861

  4. Sickle cell considerations in athletes.

    PubMed

    Eichner, E Randy

    2011-07-01

    This article highlights the exertional-sickling collapse syndrome in athletes with sickle cell trait (SCT). It covers all aspects of this syndrome, including pathophysiology, new research on microcirculatory changes, clinical features, differential diagnosis, prevention, and treatment. Also covered in this article are other clinical concerns for athletes with SCT, including lumbar myonecrosis, splenic infarction, hematuria, hyposthenuria, and venous thromboembolism. The final section offers practical points on athletes with sickling hemoglobinopathies more serious than SCT. PMID:21658547

  5. The Electrocardiogram in Athletes Revisited

    PubMed Central

    Katritsis, George D; Katritsis, Demosthenes G

    2013-01-01

    Cardiovascular-related sudden death is the leading cause of mortality in athletes during sport. Thus, it is of clinical importance to identify ECG changes that represent normal adaptation in athletes, and differentiate them from truly pathological findings. However, a distinction between adaptive and pathological ECG changes in athletes is not always easy. This article discusses exercise-induced ECG changes and the differential diagnosis of conditions that present with similar ECG patterns. PMID:26835048

  6. The aging athlete.

    PubMed

    Menard, D; Stanish, W D

    1989-01-01

    In summary, the purpose of this material is to demonstrate that the aging athlete does differ from the younger competitor in many facets. There are physiological, structural, and psychosocial differences which distinguish them as a unique entity in the athletic world. Despite the unavoidable alterations that the passage of time imposes on our bodies, these competitors are still capable of incredible performances of strength, skill, and endurance. In reference to injury, these athletes are at risk from both their current program and their past indiscretions. The literature strongly suggests that the greatest threat to the health of the aging athlete is not the aging process itself but rather inactivity. Astrand concurs with this and states that "there is less risk in activity than in continuous inactivity--it is more advisable to pass a careful physical examination if one intends to be sedentary in order to establish whether one's state of health is good enough to stand the inactivity." It appears that the body systems were designed to reinforce activity and when there is disuse, a large number of atrophic changes take place. It has been estimated that regular exercise may be able to retard the physiologic decline associated with old age as much as 50%. Taken in this light, exercise is truly a fountain of youth from which we can all rejuvenate ourselves. Science has proven that life does not begin at 40, but it has also demonstrated that it does not have to end there. As one author so aptly states, "Not too many years ago the words grandma and grandpa conjured images of rocking chairs and inactivity."(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2667376

  7. Traumatic injuries to athletes.

    PubMed

    Sigurdsson, Asgeir; Bourguignon, Cecilia

    2015-01-01

    The timeliness of treatment after dental trauma is crucial to successful tooth preservation. This article focuses on the emergency treatment of common forms of dental trauma in athletes, both at the site of the injury and at the dental office. When dental injuries happen to young patients, saving the tooth is an absolute priority, because few long-term replacement solutions can be performed in a growing child. Preserving pulpal vitality of immature teeth is essential to allow continued root development. PMID:26545271

  8. Acne mechanica in athletes.

    PubMed

    Basler, R S

    1992-08-01

    Acne mechanica is a papulopustular eruption caused by the physical factors of pressure, occlusion, friction, and heat acting upon the skin, either separately or in unison. Athletes in certain sports are at particular risk for this condition. Dermatologists, if familiar with its presentation, can play a critical role in relieving its distracting symptoms during a competitive season, and eliminating it completely at the season's end. PMID:1387355

  9. Groin pain in athletes.

    PubMed

    Macintyre, Jim; Johson, Chris; Schroeder, Erik L

    2006-12-01

    Groin pain is a common and often frustrating problem in athletes who engage in sports involving kicking, rapid accelerations and decelerations, and sudden direction changes. The most common problems are adductor strain, osteitis pubis, and sports hernia. Other causes must be considered, including nerve pain, stress fractures, and intrinsic hip pathology. There is significant overlap and multiple problems frequently coexist. Accurate diagnosis leads to directed treatment, with rehabilitation focused on functional closed-chain strengthening and core stability. PMID:17067496

  10. The effect of different warm-up stretch protocols on 20 meter sprint performance in trained rugby union players.

    PubMed

    Fletcher, Iain M; Jones, Bethan

    2004-11-01

    The purpose of this study was to determine the effect of different static and dynamic stretch protocols on 20-m sprint performance. The 97 male rugby union players were assigned randomly to 4 groups: passive static stretch (PSS; n = 28), active dynamic stretch (ADS; n = 22), active static stretch (ASST; n = 24), and static dynamic stretch (SDS; n = 23). All groups performed a standard 10-minute jog warm-up, followed by two 20-m sprints. The 20-m sprints were then repeated after subjects had performed different stretch protocols. The PSS and ASST groups had a significant increase in sprint time (p < or = 0.05), while the ADS group had a significant decrease in sprint time (p < or = 0.05). The decrease in sprint time, observed in the SDS group, was found to be nonsignificant (p > or = 0.05). The decrease in performance for the 2 static stretch groups was attributed to an increase in the musculotendinous unit (MTU) compliance, leading to a decrease in the MTU ability to store elastic energy in its eccentric phase. The reason why the ADS group improved performance is less clear, but could be linked to the rehearsal of specific movement patterns, which may help increase coordination of subsequent movement. It was concluded that static stretching as part of a warm-up may decrease short sprint performance, whereas active dynamic stretching seems to increase 20-m sprint performance. PMID:15574098

  11. HIP ARTHROSCOPY IN ATHLETES

    PubMed Central

    Polesello, Giancarlo Cavalli; Keiske Ono, Nelson; Bellan, Davi Gabriel; Honda, Emerson Kiyoshi; Guimarães, Rodrigo Pereira; Junior, Walter Riccioli; Do Val Sella, Guilherme

    2015-01-01

    To confirm the therapeutic importance of hip arthroplasty in athletes whose pain precludes sportive function of the hip joint, being able to minimize it to the extent of helping on the return of sports practice at satisfactory levels. Methods: 49 athlete patients (51 hips) submitted to hip arthroscopy complaining of pain and inability to practice sports were assessed. Follow-up time ranged from 12 to 74 months (mean: 39.0 months). Preoperatively, pain site, severity according to Facial Expression Scale (FES) and the degree of disability using the modified Harris Hip Score (HHS) were assessed. Different diagnoses were provided, which led to the indication of arthroscopy, such as femoralacetabular impact, acetabular lip injury not secondary to femoral-acetabular impact, etc. Postoperatively, the patients were assessed by using the same methods as used at baseline and by the subjective analysis of return to sports activities. Results: Based on pre-and postoperative HHS and FES, the statistical analysis showed significance between values. We found some improvement in all cases and return to sports activities at a satisfactory level in most of the cases. Conclusion: As a result of our study, we confirm that arthroscopy in athletes with local hip injuries is an effective technique, able to promote the return to sports practice in most of the cases, without pain, and with an effective joint function, provided well indicated. PMID:26998449

  12. The athlete's hip and groin.

    PubMed

    Tammareddi, Kumar; Morelli, Vincent; Reyes, Miguel

    2013-06-01

    Groin and hip injuries are seen in athletes who perform quick directional changes and cutting movements. Because forces generated through athletic performance are transferred through the hip, injuries to these areas may limit athletes with mild pain or lead to career-ending injuries. The anatomy of the hip and groin is complex and symptoms often overlap. This article discusses some athletic causes, but other medical conditions may be associated with hip and groin pain as well. Updates in evaluation and treatment are discussed for adductor strains, hip osteoarthritis, femoroacetabular impingement, sports hernia, osteitis pubis, and obturator nerve entrapment. PMID:23668647

  13. Genetic influence on athletic performance

    PubMed Central

    Guth, Lisa M.; Roth, Stephen M.

    2014-01-01

    Purpose of review The purpose of this review is to summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes. Recent findings Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children. Summary A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success. PMID:24240283

  14. [ERGOGENIC SPORT SUPPLEMENTS FOR ATHLETES].

    PubMed

    Arieli, Rakefet; Lahav, Yair

    2016-06-01

    Use of performance-enhancing supplements occurs at all levels of sports, from recreational athletes to professional athletes. Although some supplements do enhance athletic performance, many have no proven benefits and have adverse effects. Nutritional supplements are categorized into the following categories: I. Apparently Effective. II. Possibly Effective. III. Too Early To Tell. IV. Apparently Ineffective. This article will review 4 ergogenic supplements which are categorized in the first category--"Apparently Effective"--1) Buffer agents 2) Creatine 3) Caffeine and 4 Nitric Oxide. Given the widespread use of performance enhancing supplements, physicians, and dietitians should be prepared to counsel athletes about their effectiveness, safety and legality. PMID:27544991

  15. Electrocardiographic Screening in National Collegiate Athletic Association Athletes.

    PubMed

    Drezner, Jonathan A; Owens, David S; Prutkin, Jordan M; Salerno, Jack C; Harmon, Kimberly G; Prosise, Shelley; Clark, Alana; Asif, Irfan M

    2016-09-01

    The most effective protocol for cardiovascular screening of competitive athletes remains highly controversial. This study was a prospective, multicenter trial of cardiovascular screening at 35 National Collegiate Athletic Association institutions. Screening included a standardized history and physical examination (PE) as recommended by the American Heart Association and a 12-lead electrocardiogram (ECG) at rest. Centralized electrocardiographic interpretation was provided using the Seattle criteria. Athletes with screening abnormalities underwent additional evaluation directed by the host institution medical team. Primary outcomes included the proportion of total and false-positive screens; the sensitivity, specificity, and positive predictive value of history, PE, and ECG; and the prevalence of serious cardiovascular disorders associated with severe morbidity or sudden cardiac death. From August 2012 to June 2014, 5,258 athletes from 17 intercollegiate sports were screened: 55% men (mean age 20.1 years), 73% Caucasian, 16% African-American, and 11% other/mixed race. At least 1 positive cardiac symptom or family history response was reported by 1,750 athletes (33.3%). PE was abnormal in 108 athletes (2.1%), and electrocardiographic abnormalities were present in 192 athletes (3.7%). Thirteen athletes (0.25%) were identified with serious cardiac conditions including hypertrophic cardiomyopathy (1), large atrial septal defect with right ventricular dilation (1), and ventricular pre-excitation (11). The false-positive rate for history was 33.3%, PE 2.0%, and ECG 3.4%. The sensitivity/specificity/positive predictive value for history was 15.4%/66.9%/0.1%, PE 7.7%/98.2%/0.9%, and ECG 100%/96.6%/6.8%. In conclusion, electrocardiographic screening in National Collegiate Athletic Association athletes has a low false-positive rate and provides superior accuracy compared with a standardized history and PE to detect athletes with potentially dangerous cardiovascular

  16. The biomechanics of running in athletes with previous hamstring injury: A case-control study.

    PubMed

    Daly, C; McCarthy Persson, U; Twycross-Lewis, R; Woledge, R C; Morrissey, D

    2016-04-01

    Hamstring injury is prevalent with persistently high reinjury rates. We aim to inform hamstring rehabilitation by exploring the electromyographic and kinematic characteristics of running in athletes with previous hamstring injury. Nine elite male Gaelic games athletes who had returned to sport after hamstring injury and eight closely matched controls sprinted while lower limb kinematics and muscle activity of the previously injured biceps femoris, bilateral gluteus maximus, lumbar erector spinae, rectus femoris, and external oblique were recorded. Intergroup comparisons of muscle activation ratios and kinematics were performed. Previously injured athletes demonstrated significantly reduced biceps femoris muscle activation ratios with respect to ipsilateral gluteus maximus (maximum difference -12.5%, P = 0.03), ipsilateral erector spinae (maximum difference -12.5%, P = 0.01), ipsilateral external oblique (maximum difference -23%, P = 0.01), and contralateral rectus femoris (maximum difference -22%, P = 0.02) in the late swing phase. We also detected sagittal asymmetry in hip flexion (maximum 8°, P = 0.01), pelvic tilt (maximum 4°, P = 0.02), and medial rotation of the knee (maximum 6°, P = 0.03) effectively putting the hamstrings in a lengthened position just before heel strike. Previous hamstring injury is associated with altered biceps femoris associated muscle activity and potentially injurious kinematics. These deficits should be considered and addressed during rehabilitation. PMID:25913546

  17. Effects of electrostimulation and plyometric training program combination on jump height in teenage athletes.

    PubMed

    Martínez-López, Emilio J; Benito-Martínez, Elisa; Hita-Contreras, Fidel; Lara-Sánchez, Amador; Martínez-Amat, Antonio

    2012-01-01

    The purpose of this study was to examine the effects of eight-week (2 days/week) training periods of plyometric exercises (PT) and neuromuscular electrostimulation (EMS) on jump height in young athletes. Squat jump (SJ), counter movement jump (CMJ) and drop jump (DJ) were performed to assess the effects of the training protocols 98 athletes (100 & 200m and 100m & 110m hurdles) voluntarily took part in this study, 51 males (52%) and 47 females (48%), 17.91 ± 1.42 years old, and 5.16 ± 2.56 years of training experience. The participants were randomly assigned to four different groups according to the frequency and the timing of the stimulation. Analysis of covariance was used to analyze the effects of every training program on jump height. Our findings suggest that compared to control (Plyometrics (PT) only), the combination of 150Hz EMS + PT simultaneously combined in an 8 week (2days/week) training program, we could observe significant jump height improvements in the different types of strength: explosive, explosive-elastic, and explosive-elastic-reactive. The combination of PT after ≤ 85 Hz EMS did not show any jump height significant increase in sprinters. In conclusion, an eight week training program (with just two days per week) of EMS combined with plyometric exercises has proven useful for the improvement of every kind of vertical jump ability required for sprint and hurdles disciplines in teenage athletes. PMID:24150085

  18. Optimization of a parallel permutation testing function for the SPRINT R package.

    PubMed

    Petrou, Savvas; Sloan, Terence M; Mewissen, Muriel; Forster, Thorsten; Piotrowski, Michal; Dobrzelecki, Bartosz; Ghazal, Peter; Trew, Arthur; Hill, Jon

    2011-12-10

    The statistical language R and its Bioconductor package are favoured by many biostatisticians for processing microarray data. The amount of data produced by some analyses has reached the limits of many common bioinformatics computing infrastructures. High Performance Computing systems offer a solution to this issue. The Simple Parallel R Interface (SPRINT) is a package that provides biostatisticians with easy access to High Performance Computing systems and allows the addition of parallelized functions to R. Previous work has established that the SPRINT implementation of an R permutation testing function has close to optimal scaling on up to 512 processors on a supercomputer. Access to supercomputers, however, is not always possible, and so the work presented here compares the performance of the SPRINT implementation on a supercomputer with benchmarks on a range of platforms including cloud resources and a common desktop machine with multiprocessing capabilities. Copyright © 2011 John Wiley & Sons, Ltd. PMID:23335858

  19. Optimization of a parallel permutation testing function for the SPRINT R package

    PubMed Central

    Petrou, Savvas; Sloan, Terence M; Mewissen, Muriel; Forster, Thorsten; Piotrowski, Michal; Dobrzelecki, Bartosz; Ghazal, Peter; Trew, Arthur; Hill, Jon

    2011-01-01

    The statistical language R and its Bioconductor package are favoured by many biostatisticians for processing microarray data. The amount of data produced by some analyses has reached the limits of many common bioinformatics computing infrastructures. High Performance Computing systems offer a solution to this issue. The Simple Parallel R Interface (SPRINT) is a package that provides biostatisticians with easy access to High Performance Computing systems and allows the addition of parallelized functions to R. Previous work has established that the SPRINT implementation of an R permutation testing function has close to optimal scaling on up to 512 processors on a supercomputer. Access to supercomputers, however, is not always possible, and so the work presented here compares the performance of the SPRINT implementation on a supercomputer with benchmarks on a range of platforms including cloud resources and a common desktop machine with multiprocessing capabilities. Copyright © 2011 John Wiley & Sons, Ltd. PMID:23335858

  20. Optimising sprint interval exercise to maximise energy expenditure and enjoyment in overweight boys.

    PubMed

    Crisp, Nicole A; Fournier, Paul A; Licari, Melissa K; Braham, Rebecca; Guelfi, Kym J

    2012-12-01

    The aim of this study was to identify the sprint frequency that when supplemented to continuous exercise at the intensity that maximises fat oxidation (Fat(max)), optimises energy expenditure, acute postexercise energy intake and enjoyment. Eleven overweight boys completed 30 min of either continuous cycling at Fat(max) (MOD), or sprint interval exercise that consisted of continuous cycling at Fat(max) interspersed with 4-s maximal sprints every 2 min (SI(120)), every 1 min (SI(60)), or every 30 s (SI(30)). Energy expenditure was assessed during exercise, after which participants completed a modified Physical Activity Enjoyment Scale (PACES) followed by a buffet-type breakfast to measure acute postexercise energy intake. Energy expenditure increased with increasing sprint frequency (p < 0.001), but the difference between SI(60) and SI(30) did not reach significance (p = 0.076), likely as a result of decreased sprint quality as indicated by a significant decline in peak power output from SI(60) to SI(30) (p = 0.034). Postexercise energy intake was similar for MOD, SI(120), and SI(30) (p > 0.05), but was significantly less for SI(60) compared with MOD (p = 0.025). PACES was similar for MOD, SI(120), and SI(60) (p > 0.05), but was less for SI(30) compared with MOD (p = 0.038), SI(120) (p = 0.009), and SI(60) (p = 0.052). In conclusion, SI(60) appears optimal for overweight boys given that it maximises energy expenditure (i.e., there was no additional increase in expenditure with a further increase in sprint frequency) without prompting increased energy intake. This, coupled with the fact that enjoyment was not compromised, may have important implications for increased adherence and long-term energy balance. PMID:23176528