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Abstract: Willingham, BD, Daou, M, VanArsdale, J, Thomas, M, and Saracino, PG. Energy availability in female collegiate beach volleyball athletes. J Strength Cond Res 38(11): 1941-1950, 2024-Low energy availability (LEA) is a present risk for many female athletes. Yet, the literature on LEA is often reliant on single, short-term, snapshots, which may not be reflective of the chronic energy balance surrounding female athletes in sport. Therefore, the purpose of this study was to establish the current prevalence of LEA in female collegiate beach volleyball athletes during the preseason and across the competitive season. One-way repeated measures analysis of variance was used to compare measures of EA (i.e., dietary intake, activity energy expenditure [EE], body composition) and EE (i.e., resting metabolic rate and thermic effect of feeding) at 4 timepoints-once in the preseason (i.e., Fall), and 3 times across the 10-week competitive season in Spring (i.e., week 1, week 5, and week 9). Significance was set at p ≤ 0.05. Although mean EA was in the subclinical zone (i.e., 30-45 kcal·kg FFM-1·d-1) at each timepoint, the prevalence of LEA for individuals was 30.8% in the preseason, 37.5% at week 1, 25.0% at week 5, and 62.5% at week 9. Further, carbohydrate intake was below the recommended range for power athletes at each timepoint, suggesting that female beach volleyball athletes with LEA may benefit from increasing carbohydrate intake. Despite no statistical differences in body mass across the season (p = 0.577), there was a trend for increasing fat-free mass (p = 0.062) as the season progressed. Importantly, LEA is not a team-wide condition but an individual one. Therefore, approaches to mitigate LEA should be individualized., (Copyright © 2024 National Strength and Conditioning Association.)

Abstract: Yeargin, SW, Meyer, CM, Hirschhorn, RM, Lane, AD, Arent, SM, and Haggard, CR. Characterization of health and safety resources for athletes with sickle cell trait at NCAA institutions. J Strength Cond Res 38(11): 1967-1973, 2024-The purpose of this study was to report the prevalence of student-athletes with sickle cell trait (SCT), determine which screening practices are most commonly used, describe the health and human performance services provided to athletes, and ascertain if differences between National Collegiate Athletic Association (NCAA) designations or divisions exist. A cross-sectional survey design was used to query healthcare administrators regarding SCT resources at their institution. The independent variables were designation (historically Black colleges or universities [HBCUs] or non-HBCU) and Division (DI, DII, and DIII). The dependent variables were SCT prevalence, and the health and human performance services provided to athletes. Of the 60 respondents, HBCU ( n = 16) reported 4.9 ± 2.7% of athletes with SCT, which was higher than non-HBCU (1.1 ± 0.8%; p = 0.022). Historically Black colleges or university reported a higher percentage of student-athletes supplying their own screening results than non-HBCU (52.5 ± 39.2 vs. 12.9 ± 24.0%; p = 0.022). Division III reported higher proportions of waivers than DI (68.3 ± 38.4 vs. 16.9 ± 31.0%; p = 0.010). Most schools ( n = 42, 70.0%) reported having policy and procedures regarding exertional sickling, but none ( n = 60, 100.0%) involved strength and conditioning coaches (SCCs) during development. Practically, a greater proportion of DII and DIII institutions do not have supplemental oxygen available compared with DI but not statistically ( p = 0.058). Pragmatically, the prevalence should be considered when ordering and preparing resources annually. NCAA institutions need to create policy and procedure sections beyond screening. Athletic trainers and SCCs need to have a strong collaborative relationship to optimize health and human performance services., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the National Strength and Conditioning Association.)

Abstract: Dunican, IC, Galpin, A, Turner, M, and Reale, R. Sleep behaviors and nutritional knowledge in amateur and professional combat sport athletes. J Strength Cond Res 38(9): 1627-1634, 2024-Combat sports is a term applied to various competitive contact sports involving 2 competitors engaging in a bout or contest under a specific ruleset. Little is known about combat sports athletes' sleep and nutritional knowledge. This study aimed to assess (a) sleep behaviors, (b) alcohol and shiftwork disorders, and (c) the nutritional knowledge of combat sports athletes. Subjects completed various demographic questions and estimations of their weight management practices and validated surveys, including the Athlete Sleep Behavior Questionnaire, Shiftwork Disorder (SWD) Screening Questionnaire, Alcohol Use Disorders Identification Test, and the Abridged Nutrition for Sports Knowledge Questionnaire. A total of 844 combat sports athletes completed the survey, 79% male, height of 177 ± 10 (cm), and body mass of 79 ± 15 (kg). Subjects were categorized into their specific combat sport type (e.g., boxing or Brazilian jiu-jitsu [BJJ]) and by their level (professional or amateur). Sleep quality was average for all combat sport types and risk prevalence of shiftwork disorder at 11%. Mann-Whitney U tests revealed that amateurs, compared with professional strikers ( p = 0.046, CLES = 0.80), boxers ( p = 0.01, CLES = 0.78), and BJJ ( p = 0.046, CLES = 0.61) athletes, consumed significantly more alcohol. A Friedman test showed significant ( p < 0.001, W = 0.51) differences in weight between time points, with most combat sports athletes reducing weight for competition. An overall nutritional knowledge average of 55% was reported. This study highlights a critical gap in the knowledge and practices of combat sports athletes in relation to sleep behaviors and disorders, alcohol consumption, and nutritional knowledge, emphasizing the need for targeted educational interventions., (Copyright © 2024 National Strength and Conditioning Association.)

Abstract: Floersch, S, Vidden, C, Askow, AT, Jones, MT, Fields, JB, and Jagim, AR. Seasonal changes in match demands and workload distribution in collegiate soccer across two seasons. J Strength Cond Res 38(8): 1440-1446, 2024-The purpose of this study was to examine seasonal changes in match demands in a collegiate women's soccer team. Forty-eight NCAA Division III women soccer athletes (age: 19.5 ± 1.2 years; height: 1.67 ± 0.05 m; body mass: 64.8 ± 7.4 kg; fat-free mass: 50.0 ± 4.5 kg; body fat %: 22.6 ± 6.0) were equipped with wearable global positioning systems with inertial sensors and heart rate (HR) monitors during matches throughout the 2019 (n = 22) and 2021 seasons (n = 26). Players were classified by position: flank player (FP; n = 28), center midfielder (CM; n = 11), and center back fielder (CB; n = 9) and as starters (S, n = 17) or reserves (R, n = 31). Variables included HR, training load, total distance, high-speed distance, distance per minute, and weighted distance. Differences in match and practice session demands were analyzed using linear mixed-effects models with season (2 levels; 2019 and 2021) as a fixed factor, with alpha set to p = 0.05. Data across all matches and training sessions were collapsed and presented as mean ± SD for descriptive purposes and then grouped by session type (i.e., match or training) and position. Athletes traveled more distance at high speeds during match play in the 2021 season compared with 2019 (mean difference, 95% confidence intervals [CI]) (200, 95% CI: 104, 304 km; p < 0.05) but had a lower training load in 2021 compared with 2019 (-50, 95% CI: -63, -36; p < 0.05) during match play. For training sessions, mean HR (4, 95% CI: 2, 5 bpm), total distance (0.5, 95% CI: 0.4, 0.7), distance per minute (5.6, 95% CI: 4.5, 6.7 m·min-1), high-speed distance (43, 95% CI: 43, 18, 67 m), high accelerations (8.6, 95% CI: 5.4, 11.8 n), and high accelerations per minute (0.1, 95% CI: 0.1, 0.1 n·min-1) were all higher in 2021 compared with 2019 (p < 0.05). As a team, several differences in measures of external workload were found between seasons in both session types (training and matches). Variations in positional demands of match play appear to fluctuate by year., (Copyright © 2024 National Strength and Conditioning Association.)

Abstract: Philipp, NM, Cabarkapa, D, Blackburn, SD, and Fry, AC. Dose-response relationship for external workload and neuromsuclar performance over a female, collegiate, basketball season. J Strength Cond Res 38(5): e253-e263, 2024-The aim of this study was to investigate the relationship between external workload exposure and changes in countermovement jump force-time characteristics over the course of an entire basketball season, in a sample of National Collegiate Athletic Association Division I, female, basketball players. Data for 12 players were retrospectively analyzed, with external workload being quantified by means of an exponentially weighted, acute, and chronic workload, as well as an acute:chronic workload ratio derived from an inertial measurement unit-based system worn by athletes for all practices and games during the regular season. Countermovement jumps were performed on a total of 26 test days over the span of the in-season competitive period. To statistically analyze these relationships, and to account for multiple observations of the same athletes in a data set, linear mixed-effects models with athlete identity (ID) intercept as the random effect were used. Study findings suggested that associations between external workload exposure and respective force-time characteristics after controlling for the random effect of athlete ID were dependent on the specific metric or metric subgroup used, as well as the type of workload exposure (e.g., acute vs. chronic). Force-time signatures from the braking phase (e.g., average braking force) seemed to be particularly associated with higher degrees of acute workload exposure, whereas strategy-based metrics such as countermovement depth showed significant associations with chronic workload exposure. Furthermore, model results suggested the importance of analyzing neuromuscular responses to external workload on an individual basis, rather than across an entire team. Findings might help practitioners in their selection process related to metrics of interest in monitoring neuromuscular fatigue and readiness., (Copyright © 2023 National Strength and Conditioning Association.)

Abstract: Lum, D, Joseph, R, Ong, KY, Tang, JM, and Suchomel, TJ. Comparing the effects of long-term vs. periodic inclusion of isometric strength training on strength and dynamic performances. J Strength Cond Res 37(2): 305-314, 2023-This study compared the effects of including isometric strength training (IST) for consecutive 24 weeks (CIST) against a periodic inclusion (PIST) of this mode of training on strength and dynamic performances. Twenty-four floorball athletes (age: 23 ± 2.7 years, stature: 1.74 ± 2.08 m, and body mass: 72.7 ± 14.4 kg) were randomly assigned to the control (CON), CIST, or PIST group. Athletes completed 20-m sprint, countermovement jump (CMJ), and isometric midthigh pull (IMTP) during pre-test and were tested on weeks 6, 12, 18, and 24. All groups performed a similar strength training program twice per week. However, 2 sets of squats were replaced with isometric squat in CIST for all 24 weeks but only on weeks 1-6 and 13-18 for PIST. A significant main effect for time was observed for 5-, 10-, and 20-m sprint time, CMJ height, peak force, peak power, time to take-off, modified reactive strength index, IMTP peak force, relative peak force, and force at 200 milliseconds ( p = <0.001-0.037). Isometric strength training for 24 consecutive weeks resulted in greater improvement in 5-m sprint time than CON at week 24 ( p = 0.024, g = 1.17). Both CIST and PIST resulted in greater improvements in 10-m sprint time than CON at various time points ( p = 0.007-0.038 and 0.038, g = 1.07-1.44 and 1.18, respectively). Isometric strength training for 24 consecutive weeks and PIST resulted in greater improvements in 20-m sprint time than CON at week 6 ( p = 0.007 and 0.025, g = 1.65 and 1.40, respectively). The results showed that the inclusion of IST resulted in greater improvements in sprint performance than CON but no significant difference in all measured variables with PIST., (Copyright © 2022 National Strength and Conditioning Association.)

Sassone, J, Muster, M, and Barrack, MT. Prevalence and predictors of higher-risk supplement use among National Collegiate Athletic Association Division I athletes. J Strength Cond Res 33(2): 443-450, 2019-This study aimed to identify the prevalence and predictors associated with the use of higher-risk dietary supplements, defined as supplements containing herbal ingredients, caffeine, or those classified for weight loss, muscle-building, or as a preworkout supplement, among 557 National Collegiate Athletic Association Division I male and female collegiate athletes. Although 252 (45.2%) athletes reported the use of a dietary supplement on ≥2 days per week over the past year, 46 (8.3%) athletes met criteria for higher-risk supplement use. Twenty (3.6%) athletes reported the use of herbal, 1 (0.2%) caffeinated, 5 (0.9%) weight loss, 28 (5.0%) preworkout, and 1 (0.2%) muscle-building supplements. Body mass index status (BMI ≥30 kg·m), sport-type (sports using the phosphocreatine energy system), and college year (≥4th year) were associated with the use of preworkout, muscle-building, or herbal supplements. A multiple regression analysis identified predictors of higher-risk supplement use including the number of dietary supplements used in the past year (odds ratio [OR] = 2.1, 95% confidence interval [CI] = 1.7-2.7, p < 0.001), the reported motivation of taking dietary supplements to gain muscle and lose body fat (OR = 3.5, 95% CI = 1.1-11.7, p = 0.04), and the motivation to increase athletic endurance (OR = 3.5, 95% CI = 4.0, 95% CI = 1.6-9.9, p < 0.005). These factors may be considered as a part of a screening process to evaluate athletes with an increased risk of higher-risk supplement use and potential consequences to health or eligibility status.

Hammami, R, Sekulic, D, Selmi, MA, Fadhloun, M, Spasic, M, Uljevic, O, and Chaouachi, A. Maturity status as a determinant of the relationships between conditioning qualities and preplanned agility in young handball athletes. J Strength Cond Res 32(8): 2302-2313, 2018-Studies performed thus far have not accounted for the potential influence of maturity on determinants of preplanned agility. This study aimed to examine how determinants of preplanned agility are affected by the period of peak height velocity (PHV) regarding the anthropometrics and conditioning qualities in young handball players. The sample comprised 56 handball players (male; 12-14 years of age), allocated into 2 groups according to their biological age of maturity: Pre-PHV (N = 34) and Post-PHV (N = 22). Players were evaluated on handball-specific tests of preplanned agility (CODAT and T-HALF). Predictors included anthropometrics, sprinting, horizontal and vertical jumps, and reactive strength index (RSI). The reliability of the tests was appropriate (intraclass correlation coefficient: 0.87-0.95; coefficient of variation: 4.4-5.8%). In the Pre-PHV group, 67% variance of the T-HALF accounted for horizontal countermovement jump (β: -0.83, p < 0.01), 20-m sprint (β: 0.91, p < 0.01), and body mass (β: 0.19, p = 0.02). In the Post-PHV group, 80% of the T-HALF variance was explained, with a significant influence of 20-m sprint (β: 0.52, p < 0.01), RSI (β: -0.24, p = 0.04), and standing long jump (β: -0.57, p = 0.03). In the Pre-PHV group, 45% of the CODAT variance accounted for the partial influence of body fat percentage (β: 0.44, p = 0.04) and a 20-m sprint (β: 0.74, p < 0.01). In the Post-PHV group, the predictors accounted for 79% of the CODAT variance, with a significant influence of the RSI (β: -0.26, p = 0.04) and a 10-m sprint (β: 0.87, p = 0.03). Our results reinforce the need for differential strength and conditioning programs aimed at improving the preplanned agility of young athletes who differ in maturity status.

Lathlean, TJH, Gastin, PB, Newstead, S, and Finch, CF. Elite junior Australian football players experience significantly different loads across levels of competition and training modes. J Strength Cond Res 32(7): 2031-2038, 2018-Well-developed physical qualities such as high jumping ability, running endurance, acceleration, and speed can help aspiring junior elite Australian football (AF) players transition to the Australian Football League competition. To do so, players need to experience sufficient load to enhance their physical resilience without increasing their risk of negative outcomes in terms of impaired wellness or injury. The aim of this study was to investigate the differences in load for different levels of competition and training modes across one competitive season. Elite junior AF players (n = 562, aged 17.7 ± 0.3, range: 16-18 years) were recruited from 9 teams across the under-18 state league competition in Victoria. All players recorded their training and match intensities according to the session rating of perceived exertion method. Training sessions were categorized according to skills, strength, conditioning, and other activities, whereas matches were identified according to level of competition. The loads in U18 state league matches (656.7 ± 210.9 au) were significantly higher (p = 0.027) than those in school matches (643.3 ± 260.9 au) and those in U18 representative matches (617.2 ± 175.4). Players, who undertook more than one match per week, experienced significantly less load in subsequent matches (p < 0.001). Furthermore, U18 state league training sessions carried the most load when compared with other training modes. This article highlights that different combinations of training and match involvement affect overall player load, which may predispose players to negative outcomes such as impaired wellness or increased injury risk.

Schlingermann, BE, Lodge, CA, Gissane, C, and Rankin, PM. Effects of the Gaelic Athletic Association 15 on lower extremity injury incidence and neuromuscular functional outcomes in collegiate Gaelic games. J Strength Cond Res 32(7): 1993-2001, 2018-The purpose of this observational analytical cohort study was to assess the effectiveness of an injury prevention program (IPP)-Gaelic Athletic Association 15 (GAA15)-on the incidence of injury in collegiate Gaelic games. One hundred and thirty-one Gaelic games players (mean age 20.5 years ± SD 3.0) were used for analysis in this study. Participants completed preseason and postseason testing which involved performance of the Y-Balance Test. The GAA15 was used for the intervention group; coaches were instructed to implement the program before every training session and match throughout the collegiate Gaelic Athletic Association (GAA) season. The control group adopted their normal warm-up procedures for the season. The players' injuries were documented on a weekly basis by allied health care professionals working with the teams using an online database system. Results showed significant improvements in composite Y-Balance scores in favor of the intervention group (adjusted mean difference Right: 1.8 % normalized mean reach distance (%NMRD) [p = 0.007]/Left: 2.3 %NMRD [p = 0.001]). Injury rates in the intervention group (2.62 injuries per 1,000 hours) were reduced by 66% (p = 0.001) in comparison with an age-matched control group (7.62 per 1,000 hour). Training injuries, hamstring injuries, noncontact injuries, and severe injuries were also reduced as a result of the implementation of the GAA15 (injury rate ratio: 0.20, 0.59, 0.39, and 0.45, respectively). Implementation of an IPP such as the GAA15 can reduce the risk of injury in Gaelic games and influence players' neuromuscular performance assessed through the Y-Balance Test.

The aim of this study was to determine the high-speed running and sprinting profiles of elite female soccer players during competitive matches using a new Optical Player Tracking system. Eight stationary video cameras were positioned at vantage points surrounding the soccer field so that when each camera view was combined, the entire field could be viewed simultaneously. After each match, an optical player tracking system detected the coordinates (x, y) of each player for every video frame. Algorithms applied to the x and y coordinates were used to determine activity variables for 12 elite female players across 7 competitive matches. Players covered 9,220-10,581 m of total distance, 1,772-2,917 m of high-speed running (3.4-5.3 m·s) distance, and 417-850 m of sprinting (>5.4 m·s) distance, with variations between positional groups (p < 0.001; partial η = 0.444-0.488). Similarly, the number of high-speed runs differed between positional groups (p = 0.002; partial η = 0.342), and a large proportion of high-speed runs (81-84%) and sprints (71-78%) were performed over distances less than 10 m. Mean time between high-speed runs (13.9 ± 4.4 seconds) and sprints (86.5 ± 38.0 seconds) varied according to playing position (p < 0.001; partial η = 0.409) and time of the match (p < 0.001; partial η = 0.113-0.310). The results of this study can be used to design match-specific conditioning drills and shows that coaches should take an individualized approach to training load monitoring according to position.

Phibbs, PJ, Roe, G, Jones, B, Read, DB, Weakley, J, Darrall-Jones, J, and Till, K. Validity of daily and weekly self-reported training load measures in adolescent athletes. J Strength Cond Res 31(4): 1121-1126, 2017-The primary aim of the study was to assess the level of agreement between the criterion session rating of perceived exertion (sRPE30min) and a practical measure of a self-reported Web-based training load questionnaire 24 hours after training (sRPE24h) in adolescent athletes. The secondary aim was to assess the agreement between weekly summated sRPE24h values (∑sRPE24h) and a weekly Web-based training diary (sRPEweekly) for all field-based training accumulated on a subsequent training week. Thirty-six male adolescent rugby players (age, 16.7 ± 0.5 years) were recruited from a regional academy. Measures of sRPE30min were recorded 30 minutes after a typical field-based training session. Participants then completed the sRPE24h via a Web-based training load questionnaire 24 hours after training, reporting both session duration and intensity. In addition, on a subsequent week, participants completed the sRPE24h daily and then completed the sRPEweekly at the end of the week, using the same Web-based platform, to recall all field-based training session durations and intensities over those 7 days. Biases were trivial between sRPE30min and sRPE24h for sRPE (0.3% [-0.9 to 1.5]), with nearly perfect correlations (0.99 [0.98-0.99]) and small typical error of the estimate (TEE; 4.3% [3.6-5.4]). Biases were trivial between ∑sRPE24h and sRPEweekly for sRPE (5.9% [-2.1 to 14.2]), with very large correlations (0.87 [0.78-0.93]) and moderate TEE of 28.5% [23.3-36.9]. The results of this study show that sRPE24h is a valid and robust method to quantify training loads in adolescent athletes. However, sRPEweekly was found to have a substantial TEE (28.5%), limiting practical application.

Deaner, RO and Lowen, A. Males and females pace differently in high school cross-country races. J Strength Cond Res 30(11): 2991-2997, 2016-Previous studies have demonstrated that men are more likely than women to slow in the marathon, but it is unknown whether the sex difference in pacing occurs for other race distances. This study addressed this question by analyzing the 5-km Virginia State Championship high school cross-country race for the years 2010, 2012, 2013, and 2014, which encompassed 3,948 performances. The pacing measure was percentage change in speed from mile 1 to mile 2. Across all runners, women (9.1%) slowed significantly (p = 0.002) more than men (8.7%), although the magnitude of the difference was trivial (effect size [ES] = -0.10). However, when women and men in physiologically equated finishing time groups (e.g., <17:00 for men; <19:03 for women) were compared, men slowed significantly more (p < 0.001) in all 4 groups, and the differences were nontrivial (ESs range 0.27-0.92). Because glycogen depletion is irrelevant for 5 km performances, these results challenge the hypothesis that the sex difference in pacing is due to males' greater susceptibility to glycogen depletion. These results instead support the hypothesis that the sex difference in pacing partly reflects a sex difference in some aspect of decision making, such as overconfidence, risk perception, or willingness to tolerate discomfort. Coaches and athletes are advised to consider individual variation in these characteristics when planning training and racing.

Beyer, KS, Fukuda, DH, Redd, MJ, Stout, JR, and Hoffman, JR. Player selection bias in National Football League draftees. J Strength Cond Res 30(11): 2965-2971, 2016-Relative age effects (RAEs) have been studied as a potential factor associated with player selection bias in numerous sports. However, little research has examined the role of RAEs among National Football League (NFL) draftees. The purpose of the current study was to determine the existence of RAEs in NFL draftees from the last 10 NFL drafts. Draftee birth dates were collected and divided into calendar and scholastic quarters (SQ1-SQ4). To determine the presence of RAEs in specific subsets, NFL draftees were grouped according to round drafted, position, level of conference play, and age at the time of the draft. Significant χ tests (p ≤ 0.05) comparing observed birth-date distributions vs. the expected birth-date distribution from the general population were followed up by calculating the standardized residual for each quarter (z > ±2.0 indicating significance). Overall, no RAEs were seen when birth-date distribution was assessed using calendar quarters (p = 0.47), but more draftees were born in SQ2 (December-February) than expected (p < 0.01; z = +2.2). Significantly more draftees were born in SQ2 than expected for middle-round draftees (p = 0.01; z = +2.4), skill positions (p = 0.03; z = +2.3), Power Five college draftees (p < 0.01; z = +2.6), and early draftees (p < 0.01; z = +3.1). However, reverse RAEs were seen among late draftees, with fewer draftees being born in SQ2 (z = -3.6) and more being born in SQ4 (June-August; z = +2.6) than expected. In contrast to previous research, the current study observed significant RAEs in NFL draftees from the last 10 years. This player selection bias should be considered when evaluating long-term athlete development models in American football.

Vitale, JA, Caumo, A, Roveda, E, Montaruli, A, La Torre, A, Battaglini, CL, and Carandente, F. Physical attributes and NFL Combine performance tests between Italian National League and American football players: a comparative study. J Strength Cond Res 30(10): 2802-2808, 2016-The purpose of this study was to examine anthropometric measurements and the results of a battery of performance tests administered during the National Football League (NFL) Combine between American football players who were declared eligible to participate in the NFL Combine and football players of a top Italian team (Rhinos Milan). Participants (N = 50) were categorized by position into 1 of 3 groups based on playing position: skill players (SP) included wide receivers, cornerbacks, free safeties, strong safeties, and running backs; big skill players (BSP) consisted of fullbacks, linebackers, tight ends, and defensive ends; lineman (LM) included centers, offensive guards, offensive tackles, and defensive tackles. A 1-way analysis of variance followed by the Tukey-Kramer post hoc test was used for comparisons between Italian players by playing position. Ninety-five percent CIs were used for comparisons between American and Italian football for the NFL Combine performance tests. Significant differences for all the variables between the 3 playing categories were observed among the Italian players; LM had higher anthropometric and body composition values than SP (p < 0.001) and BSP (p < 0.001), whereas LM performed significantly worse in the physical tests, except for the 225-lb bench press test when compared with SP (p < 0.002). American football players presented significantly higher anthropometric values and test performance scores when compared with Italian players. Administrators of professional football teams in Italy need to improve the player's physical attributes, so the gap that currently exists between American and Italian players can be reduced, which could significantly improve the quality of American football in Italy.

Stanforth, D, Lu, T, Stults-Kolehmainen, MA, Crim, BN, and Stanforth, PR. Bone mineral content and density among female NCAA Division I athletes across the competitive season and over a multi-year time frame. J Strength Cond Res 30(10): 2828-2838, 2016-Longitudinal and cross-sectional bone mineral content (BMC) and bone mineral density (BMD) comparisons were made among impact and nonimpact sports. Female collegiate athletes, 18-23 years of age, from basketball (BB; n = 38), soccer (SOC; n = 47), swimming (SW; n = 52), track sprinters and jumpers (TR; n = 49), and volleyball (VB; n = 26) had BMC/BMD measures preseason and postseason over 3 years. Control groups of 85 college females, 18-24 years of age, who completed 2 tests 1-3 years apart and of 170 college females, 18-20 years of age, were used for the longitudinal and cross-sectional analyses, respectively. A restricted maximum likelihood linear mixed model regression analysis with a compound symmetric heterogeneous variance-covariance matrix structure was used for all analyses (p ≤ 0.05). Increases from year-1 preseason to year-3 postseason included the following: total BMC (3.3%), total BMD (1.4%), and spine BMD (4.5%) for BB; total BMC (1.5%) and leg BMD (1.2%) for SOC; arm (1.8%), leg (1.9%), and total BMD (5.7%) for SW; total BMC (2.0%), arm (1.7%), leg (2.3%), pelvis (3.4%), spine (6.0%), and total BMD (2.3%) for TR; and arm (4.1%), leg (2.0%), pelvis (2.0%), spine (2.0%), and total BMD (2.7%) for VB. Comparisons among sports determined that BB had higher BMC and BMD values than all other sports for all variables except spine and total BMD; BB, SOC, TR, and VB had higher total BMC (11-29%), leg BMD (13-20%), and total BMD (9-15%) than SW and CON, and there were few differences among SOC, TR, and VB. In conclusion, small, significant increases in many BMC and BMD measures occur during female athlete's collegiate careers. The BMC and BMD differences between impact and nonimpact sports are large compared with smaller differences within impact sports.

Boscolo Del Vecchio, F, Foster, D, and Arruda, A. Functional movement screening performance of Brazilian jiu-jitsu athletes from Brazil: differences considering practice time and combat style. J Strength Cond Res 30(8): 2341-2347, 2016-Brazilian jiu-jitsu (BJJ) is a grappling combat sport that athletes, lying (guard fighter) or kneeling (pass fighter) on the mat, attempt to force their opponents to submit. Brazilian jiu-jitsu practices may result in muscular imbalances, which increase the risk of injury. Instead, the Functional Movement Screen (FMS) is an evaluation routine that could be related to injury incidence and seeks to detect muscular imbalance and movement dysfunction. Thus, the aim of the study was to investigate the injury profile and the FMS score and their relationship, with consideration for the BJJ fight style. Sports injuries were recorded in the last 12 months of 33 BJJ athletes, and the statistical analyses were applied to a routine evaluation FMS and a score of 14 points or less was considered low performance in FMS. We used a logistic regression; the effect size (ES) was calculated, and 5% was assumed as the statistical significance level. Pass fighters showed a higher percentage of injuries on the thorax (24.24%) than did guard fighters (6.67%, p = 0.01). Upper limbs were the most injured part of the body (χ = 36.7; p < 0.001), and they were 79% of the injuries that occurred in training sessions (χ = 14.53; p < 0.001). Despite the lack of statistical differences in the FMS performance between guard and pass fighters (t = 1.97; p = 0.05), its magnitude was considered medium (ES = 0.77). There was an association between FMS and presence of injury (χ = 4.95; p = 0.03). Considering the FMS score as a predictor and the presence or absence of injury as the dependent variable, the data met a Wald coefficient of 4.55, p = 0.03 and Exp (B) = 5.71. The study found that almost half of the sample had injuries in the upper limbs and a quarter had injuries in the lower limbs in the last year. A poor FMS score was observed, and lower scores in the FMS were associated with a higher risk of injury in BJJ athletes.

The purpose of this investigation was to (a) examine how asymmetry in lower extremity lean mass influenced force and power asymmetry during jumping, (b) determine how power and force asymmetry affected jump height, and (c) report normative values in collegiate athletes. Force and power were assessed from each limb using bilateral force plates during a countermovement jump in 167 division 1 athletes (mass = 85.7 ± 20.3 kg, age = 20.0 ± 1.2 years; 103 men and 64 women). Lean mass of the pelvis, thigh, and shank was assessed using dual-energy x-ray absorptiometry. Percent asymmetry was calculated for lean mass at each region (pelvis, thigh, and shank) as well as force and power. Forward stepwise regressions were performed to determine the influence of lean mass asymmetry on force and power asymmetry. Thigh and shank lean mass asymmetry explained 20% of the variance in force asymmetry (R = 0.20, p < 0.001), whereas lean mass asymmetry of the pelvis, thigh, and shank explained 25% of the variance in power asymmetry (R = 0.25, p < 0.001). Jump height was compared across level of force and power asymmetry (p > 0.05) and greater than 10% asymmetry in power tended to decrease the performance (effect size >1.0). Ninety-five percent of this population (2.5th to 97.5th percentile) displayed force asymmetry between -11.8 and 16.8% and a power asymmetry between -9.9 and 11.5%. A small percentage (<4%) of these athletes displayed more than 15% asymmetry between limbs. These results demonstrate that lean mass asymmetry in the lower extremity is at least partially responsible for asymmetries in force and power. However, a large percentage remains unexplained by lean mass asymmetry.

The purpose of this study was to determine the mean values of the functional movement screen (FMS) in a group of long-distance runners. The secondary aims were to investigate whether the FMS performance differed between sexes and between young and older runners. Forty-three runners, 16 women (mean age = 33.5 years, height = 165.2 cm, weight = 56.3 kg, and body mass index [BMI] = 20.6) and 27 men (mean age = 39.3 years, height = 177.6 cm, weight = 75.8 kg, and BMI = 24.2) performed the FMS. All the runners were injury-free and ran >30 km·wk. Independent t-tests were performed on the composite scores to examine the differences between men and women and also between young (<40 years) and older runners (>40 years). Contingency tables (2 × 2) were developed for each of the 7 screening tests to further look at the differences in groups for each single test. The χ values were calculated to determine significant differences. Statistical significance was set at p ≤ 0.05. There was no significant difference in the composite score between women and men. There were significant differences between the sexes in the push-up and straight leg test scores, with the women scoring better on each test. A significant difference was found in the composite scores between younger and older runners (p < 0.000). Additional score differences were found for the squat, hurdle step, and in-line lunge tests with the younger runners scoring better. This study provided mean values for the FMS in a cohort of long-distance runners. These values can be used as a reference for comparing FMST scores in other runners who are screened with this tool.

The purpose of this investigation was to determine the effects of a small-sided game training intervention on the intermittent shuttle running performance, speed, and repeated sprint ability of elite rugby league players during the competitive phase of a rugby league season. Ten elite rugby league players from a Stobart Super League team academy underwent 2 small-sided game sessions per week over an 8-week period. Each session consisted of four 10-minute blocks of 1 small-sided game, interspersed with a 3-minute recovery. Changes in physical performance were assessed before and after the training intervention with an intermittent shuttle running test (30-15 Intermittent Fitness Test), speed tests (10-, 20-, and 40-m linear sprints) and a repeated sprint ability test (8 × 20-m linear sprint, departing every 20 seconds). Results showed that the 30-15 Intermittent Fitness Test (+1.29%), 10-m (-3.17%), 20-m (-1.37%), and 40-m (-0.96%) sprint times and mean sprint time (-2.11%), total sprint time (-2.11%), and percentage of sprint decrement (7.10 vs. 5.93%) during the repeated sprint ability test were significantly improved after the training intervention. Based on these results, it was concluded that an 8-week small-sided game training intervention was an effective method for improving the physical performance of elite rugby league players during the competitive phase of the season.

Isokinetic concentric quadriceps and hamstring strength data using a Cybex dynamometer are collected for elite collegiate American football players invited to the annual National Football League Scouting Combine. We constructed a normative (reference) database of the Cybex strength data for the purpose of allowing comparison of an individual's values to his peers. Data reduction was performed to construct frequency distributions of hamstring/quadriceps (H/Q) ratios and side-to-side strength differences. For the cohort (n = 1,252 players), a statistically significant but very small (1.9%) mean quadriceps strength preference existed for dominant side vs. nondominant side. Peak torque (Newton meters, best repetition) for quadriceps and hamstrings was significantly correlated to player body mass (weight) (the same relationship was found for other variables using peak torque in the calculation). Peak torque varied by player position, being greatest for offensive linemen and lowest for kickers (p < 0.0001). Adjusting for body weight overcorrected these differences. The H/Q ratios and frequency distributions were similar across positions, with a mean of 0.6837 ± 0.137 for the cohort dominant side vs. 0.6940 ± 0.145 for the nondominant side (p = 0.021, n = 1,252). Considerable variation was seen for dominant-to-nondominant side difference for peak torque. For quadriceps, 47.2% of players had differences between -10% and +10%, 21.0% had a peak torque dominant-side deficit of 10% or greater compared to nondominant side, and for 31.8% of players, dominant-side peak torque was greater than 10% compared to nondominant side. For hamstrings, 57.0% of players had differences between -10% and +10%, 19.6% had a peak torque dominant-side deficit of 10% or greater compared to nondominant side, and 23.4% of players, dominant-side peak torque was greater than 10% compared to nondominant side. We observed that isokinetic absolute strength variables are dependent on body weight and vary across player position. The H/Q ratios vary only within a relatively narrow range. Side-to-side differences in strength variables >10% are common, not the exception.

The purpose of this investigation was to describe the physiological profile of elite, senior Chinese female wrestlers. Twenty-five elite wrestlers, nationally ranked in the top 3 of their weight class, participated in this study. The subjects included Olympic and world champion medalists. The physiological profile included testing of running maximal oxygen consumption (VO2max), 3,200-m run time, 400-m run time, 30-second Wingate anaerobic power and capacity, shoulder, elbow, knee, and trunk isokinetic torque, and 1 repetition maximums (1RMs) in specified exercises. The major results (mean ± SD) were VO2max: 50.58 ± 3.33 ml·kg(-1)·min(-1); 3,200-m run: 14 minutes 1 second ± 49 seconds; 400-m run: 1 minute 11 seconds ± 4 seconds; Wingate maximal anaerobic power: 495.21 ± 79.13 W and mean power: 262.97 ± 52.39 W; 1RM deadlift: 124 ± 19 kg; 1RM deep squat: 98 ± 11 kg; 1RM prone rowing: 72 ± 8 kg; 1RM power clean: 76 ± 12 kg; and 1RM hold and squat: 109 ± 17 kg. In absolute terms in the majority of measures, the heavier weight classes had greater values than the lighter weight classes, but relative to body mass, there were few differences in measures between the weight classes. The Olympic and World Championship medalist had the best value or was at the upper end of a measure's range for the strength and power measures. The results indicate that female wrestling success is not dependent on one physiological characteristic, but that a variety of physiological profiles can result in success. These data on elite female wrestlers can be compared with other wrestlers to help determine individual weaknesses or strengths and to design training programs that result in wrestling success.

The purpose of the present study was to compare the performance in repeated sprint ability (RSA) and repeated changes-of-direction (RCOD) among elite soccer players with different age categories. Forty-nine elite soccer players from the same club and from different age categories (Pro2: n = 8, U19: n = 18, U17: n = 13, and U15: n = 10) participated in this study. Each player was tested in both a RSA straight-line sprints (10 × 20 m with active recovery) and a RCOD test including four 100° COD at every 4 m (10 × 20 m with active recovery). The average time (AT), fastest time (FT), total time (TT), percentage of decrement score (%Dec), and RSA/RCOD index were recorded and calculated during all the RSA and RCOD tests. Results showed significant age group effects on RSA and RCOD parameters (p < 0.01) and RSA/RCOD index parameters (p < 0.01). Compared with other groups, U15 has significant (p < 0.05) higher values in RSA-AT, RSA-FT, RSA-TT, RCOD-AT, RCOD-FT, RCOD-TT, index-AT, index-FT, and index-TT. However, the trend of performance time and RSA/RCOD index was always similar (i.e., U15 > U17 > U19 > Pro2; Pro2 > U19 > U17 > U15) showing an age dependant for RSA and RCOD performance. The %Dec in RSA of U15 and U17 was significantly (p < 0.05) higher than U19 and Pro2, whereas the %Dec in RCOD of U15 was significantly (p < 0.05) higher than U19. In conclusion, the present study showed that the RSA and RCOD are age dependent, and therefore, coaches should plan a specific program differentiating the RSA and RCOD, while the individualized training could begin in U17.

The aim of this study was to determine the changes in anthropomorphism and performance over a 4-year eligibility career of American football players. A total of 92 offensive and defensive linemen and 64 skill (wide receivers and defensive backs) player observations were included in the analysis. Data from preseason testing over a 7-year period were compiled, sorted, and analyzed by players' year in school. Assessments of strength included 1 repetition maximum bench press, squat, power clean, and a 225-lb maximum repetition muscle endurance test. Power and speed measures included vertical jump (VJ) and 40-yd (36.6-m) sprint. All strength measures improved significantly (p < 0.05) over the years of training. Skill players demonstrated a significant increase in power between years 1 and 2 but at no other time. Linemen did not demonstrate significant changes in VJ. Speed did not change significantly for either group over the 4 years of training. These data provide a theoretically predictable 4-year rate of change in anthropometric, strength, and power variables for Division I football players. By having a longitudinal assessment of expected physical improvement, it may be possible for strength training personnel to determine those who may need additional attention in an area to more closely improve as expected. Additionally, it is suggested that elite athletes may possess genetically superior attributes and therefore, when selecting athletes, particular attention should be paid to the selection of those who have previously demonstrated superior speed and power.

Although the physiological demands of cricket match play are emerging, the demands of contemporary training practices have not been reported. The aim of this study was to quantify the physiological demands of selected cricket training activities and compare these to known match demands. Twenty-eight different training activities were monitored in national academy level cricketers (n = 42) using global positioning system units during a 14-week residential training program. The training activities were classified into 3 categories: conditioning sessions (n = 8), skill sessions (n = 9), and game simulations (n = 11). Conditioning sessions were further classified into high- (n = 4) and low- (n = 4) intensity drills. Time-motion measures included movement patterns (walk, jog, run, stride, and sprint distances), total distance covered, number of sprints, number of high-intensity efforts, maximum speed, and recovery time between high-intensity efforts. Inferential statistics were used to quantify magnitudes of difference between various training drills. Movement patterns were then compared to recently published game data (Twenty20, One-Day, and Multiday games) from the same sample group of cricketers. Conditioning drills were twice as long in duration as skill drills and twice as intense as both the skill and game simulation drills. Exercising heart rates were 9-26% and lactate levels up to 3.5 times higher in conditioning compared to other training drills. Conditioning drills matched or exceeded (up to 10 b·min⁻¹; 5%) peak game heart rates. Conversely, skill and simulation drills replicated mean game heart rates for some, but not all positions. In conclusion, training replicates or exceeds cricket match demands in conditioning-type drills but not in simulation or skill-based drills. Modification of skill and simulation training drill practices will ensure closer replication of match and training demands.

Some evidence exists that the determination of maximal lactate steady state (MLSS) with lactate minimum (LM) in highly trained athletes is not as accurate as in less trained athletes. Therefore, we compared power output at LM with power output MLSS in moderately up to highly trained subjects. 63 subjects performed a test on a cycle ergometer to determine power output at LM and 3 or more constant-load tests of 30 minutes to determine power output at MLSS. Mean power output at LM (245 ± 29 W; mean ± SD) was slightly lower than power output at MLSS (255 ± 32 W). The correlation between power output at MLSS and LM was high, and the regression line runs parallel to the line of identity showing that the results of highly trained subjects agree with the results of less trained subjects (LM and MLSS r = 0.867, p < 0.001). The modified blood-lactate kinetic in highly trained athletes compared with less trained persons does not impair accuracy at LM. Therefore, we suggest LM as a valid and meaningful concept to estimate power output at MLSS in 1 single test in moderately up to highly trained athletes.

The aim of this study was to examine the effects of wearing different grades of graduated compression stockings (GCS) on 10-km running performance. After an initial familiarization run, 9 male and 3 female competitive runners (VO₂max 68.7 ± 5.8 ml·kg⁻¹·min⁻¹) completed 4 10-km time trials on an outdoor 400-m track wearing either control (0 mm Hg; Con), low (12-15 mm Hg; Low), medium (18-21 mm Hg; Med), or high (23-32 mm Hg; Hi) GCS in a randomized counterbalanced order. Leg power was assessed pre and postrun via countermovement jump using a jump mat. Blood-lactate concentration was assessed pre and postrun, whereas heart rate was monitored continuously during exercise. Perceptual scales were used to assess the comfort, tightness, and any pain associated with wearing GCS. There were no significant differences in performance time between trials (p = 0.99). The change in pre to postexercise jump performance was lower in Low and Med than in Con (p < 0.05). Mean heart rate (p = 0.99) and blood lactate (p = 1.00) were not different between trials. Participants rated Con and Low as more comfortable than Med and Hi (p < 0.01), Med and Hi were rated as tighter than Low (p < 0.01), all GCS were rated as tighter than Con (p < 0.01), and Hi was associated with the most pain (p < 0.01). In conclusion, GCS worn by competitive runners during 10-km time trials did not affect performance time; however Low and Med GCS resulted in greater maintenance of leg power after endurance exercise. Athletes rated low-grade GCS as most comfortable garments to wear during exercise.

The aim of this article is to present data on the strength and power characteristics of forwards and backs in a squad of elite English rugby league players and compare these findings to previously published literature from Australia. Participants were elite English rugby league players (n = 18; height 184.16 ± 5.76 cm; body mass 96.87 ± 10.92 kg, age 21.67 ± 4.10 years) who were all regular first team players for an English Superleague club. Testing included 5-, 10-, 20-m sprint times, agility, vertical jump, 40-kg squat jump, isometric squat, concentric and eccentric isokinetic knee flexion and extension. Independent t-tests were performed to compare results between forwards and backs, with paired samples t-tests used to compare bilateral differences from isokinetic assessments and agility tests. Forwards demonstrated significantly (p < 0.05) greater body mass (102.15 ± 7.5 kg), height (186.30 ± 5.47 cm), power during the 40-kg jump squat (2,106 ± 421 W), isometric force (3,122 ± 611 N) and peak torque during left concentric isokinetic knee extension (296.1 ± 54.2 N·m) compared to the backs (86.30 ± 8.97 kg; 179.87 ± 3.72 cm; 1,709 ± 286 W; 2,927 ± 607 N; 241.7 ± 35.2 N·m, respectively). However, no significant differences (p > 0.05) were noted between forwards and backs during right concentric isokinetic knee extension (274.8 ± 37.7 and 246.8 ± 25.8 N·m), concentric isokinetic knee flexion for both left (158.8 ± 28.6 and 141.0 ± 22. 7 N·m) and right legs (155.3 ± 22.9 and 128.0 ± 23.9 N·m), eccentric isokinetic knee flexion and extension, hamstring quadriceps ratios, or vertical jump (37.25 ± 4.35 and 40.33 ± 6.38 cm). In comparison, relative measures demonstrated that backs performed significantly better compared to the forwards during the 40-kg jump squat (20.71 ± 5.15 and 19.91 ± 3.91 W·kg⁻¹) and the isometric squat (34.32 ± 7.9 and 30.65 ± 5.34 N·kg⁻¹). Bilateral comparisons revealed no significant differences (p > 0.05) between left and right leg performances in the agility test (3.26 ± 0.18 and 3.24 ± 0.18 seconds), or between left (0.7 ± 0.10) and right (0.71 ± 0.17) leg eccentric hamstring concentric quadriceps ratios. The results demonstrate that absolute strength and power measures are generally higher in forwards compared to in backs; however, when body mass is taken into account and relative measures compared, the backs outperform the forwards.

The best method of assessing muscular force qualities during isoinertial stretch shorten cycle lower body movements remains a subject of much debate. This study had 2 purposes: Firstly, to calculate the interday reliability of peak force (PF) measurement and a variety of force-time measures, and, secondly, to compare the reliability of the 2 most common technologies for measuring force during loaded jump squats, the linear position transducer (PT), and the force plate (FP). Twenty-five male elite level rugby union players performed 3 rebound jump squats with a 40-kg external load on 2 occasions 1 week apart. Vertical ground reaction forces (GRFs) were directly measured via an FP, and force was differentiated from position data collected using a PT. From these data, a number of force-time variables were calculated for both the FP and PT. Intraclass correlation coefficient (ICC), coefficient of variation (CV), and percent change in the mean were used as measures of between-session reliability. Additionally, Pearson's product moment correlation coefficients were used to investigate intercorrelations between variables and technologies. Both FP and PT were found to be a reliable means of measuring PF (ICC = 0.88-0.96, CV = 2.3-4.8%), and the relationship between the 2 technologies was very high and high for days 1 and 2, respectively (r = 0.67-0.88). Force-time variables calculated from FP data tended to have greater relative and absolute consistency (ICC = 0.70-0.96, CV = 5.1-51.8%) than those calculated from differentiated PT data (ICC = 0.18-0.95, CV = 7.7-93.6%). Intercorrelations between variables ranged from trivial to practically perfect (r = 0.00-1.00). It was concluded that PF can be measured reliably with both FP and PT technologies, and these measurements are related. A number of force-time values can also be reliably calculated via the use of GRF data. Although some of these force-time variables can be reliably calculated using position data, variation of measurement is generally greater when using position data to calculate force.

This study examined the relationship between 30-second anaerobic power and body composition by performance level in elite Judoists. During a 3-month period, 10 male Korean Judo national team athletes (NT), 26 male university varsity team athletes (VT), and 28 male junior varsity team athletes (JT) were assessed for 30-second anaerobic power and body composition at the Youngin University. Anaerobic power was measured using a 30-second Wingate test. Body composition was assessed via bioelectric impedance analysis in standardized conditions using BioSpace (Korean)-specific prediction formulas. All testing occurred at the beginning of the winter nonseason period but excluded a brief weight-loss period before the competition phase. Anaerobic power measures were significantly greater (p < 0.05) in NT and VT than in JT. Fat-free mass (FFM), muscle mass (MM), and total body water in JT were also greater than in VT and JT (p < 0.05). Muscle mass in VT was significantly lower than in NT (p < 0.05). Fat-free mass in NT was strongly correlated to mean and peak anaerobic power (r = 0.77, p = 0.009; r = 0.87, p < 0.001, respectively). Varsity team athletes also indicated a moderate association between FFM and peak and mean anaerobic power (r = 0.63, p < 0.001; r = 0.48, p = 0.013, respectively). However, relationship between FFM and anaerobic power was not statistically significantly correlated in JT (r = 0.14, p = 0.470; r = 0.23, p = 0.232, separately). In conclusion, our data indicated that anaerobic power is closely correlated with increase in FFM and MM and was different dependent among performance levels. Further research in the field is warranted to elucidate the Judo-specific relationship between FFM and performance.

We investigated in 73 male ultraendurance mountain bikers, with (mean and SD) age 39.1 (8.6) years, weight 74.4 (8.3) kg, height 1.78 (0.07) m, and a body mass index of 23.3 (1.9) kg·m⁻², whether variables of anthropometry, training, or prerace experience were associated with race time using bi and multivariate analysis. Our investigation was conducted at the "Swiss Bike Masters," which covers a distance of 120 km and an altitude of 5,000 m. In the bivariate analysis, body mass index (r = 0.29), circumference of upper arm (r = 0.28), sum of upper body skinfolds (r = 0.38), sum of lower body skinfolds (r = 0.25), sum of 8 skinfolds (r = 0.36), percent body fat (r = 0.41), total cycling kilometers per year (r = -0.47), yearly volume in both mountain bike (r = -0.33) and road cycling (r = -0.52), number of training units per week (r = -0.48), distance per unit in road cycling (r = -0.33), average speed during training in road cycling (r = -0.33), and personal best time in the "Swiss Bike Masters"(r = 0.67) were related to race time. In the multiple linear regression analysis, personal best time in the "Swiss Bike Masters" (p = 0.000), total yearly cycling kilometers (p = 0.004), and yearly training kilometers in road cycling (p = 0.017) were related to race time. When the personal best time was the dependent variable in a separate regression model, total yearly cycling kilometers (p = 0.002) remained the single predictor variable. We concluded that finishing a particular mountain bike ultramarathon does not seem to require a special anthropometry but rather a specific skill and experience for this selective kind of race coupled with a high training volume. For practical use, we concluded that successful athletes in a mountain bike ultramarathon, in a special environment and using sophisticated equipment, need prerace experience coupled with high training volume, rather than any special anthropometry.

The purpose of this study was to compare 4 interval training (IT) sessions with different intensities and durations of exercise to determine the effect on mean VO₂, total VO₂, and duration of exertion ≥95% maximum power output (MPO), and the effects on biomarkers of fatigue such as blood-lactate concentration (BLC) and rating of perceived exertion. The subjects were 12 recreationally competitive male (n = 7, mean ± SD age = 26.2 ± 3.9 years) and female (n = 5, mean ± SD age = 27.6 ± 4.3 years) triathletes. These subjects performed 4 IT sessions on a cycle ergometer varying in intensity (90 and 100% MPO) and duration of exercise (30 seconds and 3 minutes). This study revealed that IT using 30-second duration intervals (30-30 seconds) allows the athlete to perform a longer session, with a higher total and mean VO₂ HR and lower BLC than 3-minute durations. Similarly, submaximal exertion at 90% of MPO also allows performing longer sessions with a higher total VO₂ than 100% intensity. Thus, the results of the present study suggested that to increase the total time at high intensity of exercise and total VO₂ of a single exercise session performed by the athlete, IT protocols of short durations (i.e., 30 seconds) and submaximal intensities (i.e., 90% MPO) should be selected. Furthermore, performing short-duration intervals may allow the athlete to complete a longer IT session with greater metabolic demands (VO₂) and lower BLC than longer (i.e., 3 minutes) intervals.

The purpose of this study was to evaluate the effects of the speed, agility, quickness (SAQ) training method on power performance in soccer players. Soccer players were assigned randomly to 2 groups: experimental group (EG; n = 50) and control group (n = 50). Power performance was assessed by a test of quickness--the 5-m sprint, a test of acceleration--the 10-m sprint, tests of maximal speed--the 20- and the 30-m sprint along with Bosco jump tests--squat jump, countermovement jump (CMJ), maximal CMJ, and continuous jumps performed with legs extended. The initial testing procedure took place at the beginning of the in-season period. The 8-week specific SAQ training program was implemented after which final testing took place. The results of the 2-way analysis of variance indicated that the EG improved significantly (p < 0.05) in 5-m (1.43 vs. 1.39 seconds) and in 10-m (2.15 vs. 2.07 seconds) sprints, and they also improved their jumping performance in countermovement (44.04 vs. 4.48 cm) and continuous jumps (41.08 vs. 41.39 cm) performed with legs extended (p < 0.05). The SAQ training program appears to be an effective way of improving some segments of power performance in young soccer players during the in-season period. Soccer coaches could use this information in the process of planning in-season training. Without proper planning of the SAQ training, soccer players will most likely be confronted with decrease in power performance during in-season period.

Prediction of time to exhaustion in competitive cyclists from a perceptually based scale. We have tested the validity of the estimated time limit (ETL) scale to predict an exhaustion time (T(lim)) from values stemming from incremental and randomized constant workloads tests on a cycle ergometer. Twenty-five cyclists performed 1 continuous incremental test, 1 discontinuous test with randomized workloads, and 1 constant power output test at 90% of maximal aerobic power (MAP) to exhaustion. Estimated time limits at 90% MAP during the incremental test and the test with randomized workloads were calculated from exponential relationships between power and ETL using the same 4 workloads. Real measured T(lim) during the constant power output test was converted into ETL values (called measured ETL). The differences between the calculated and measured ETLs were examined. Estimated time limits calculated at 90% MAP during the incremental and randomized tests corresponded to 14 minutes 56 seconds and 10 minutes 14 seconds, whereas measured ETL was equal to 11 minutes 19 seconds ± 3 minutes 40 seconds. The results showed a nonsignificant difference between calculated and measured ETLs. However, the mean differences between the measured ETL values during the constant test performed at the same intensity were -1.3 ± 2.9 and 0.3 ± 3.0 for the incremental and the randomized constant workloads tests, respectively. Consequently, the use of ETL calculated at 90% MAP during the test with randomized constant workloads may be preferable to predict the accurate T(lim). Moreover, it would seem that high-level cyclists, who were more consciously attuned to their bodies and their own effort sense, were more accurate in their prediction than low-level cyclists. It is concluded that the randomized constant workloads test that is both shorter and less strenuous would be more convenient for high-level athletes.

The objectives of this study were to determine (a) if reactive oxygen metabolites (ROMs) are a reliable parameter for monitoring oxidative stress in athletes alone or in association with other parameters of oxidative stress and depending on whether antioxidant supplements are taken or not; (b) the level of oxidative stress in athletes before the competition season; and (c) if oxidative status could be improved in volleyball athletes. Sixteen women athletes (supplemented group) received an antioxidant cocktail containing vitamin E, vitamin C, zinc gluconate, and selenium as a dietary supplement during a 6-week training period, whereas 12 of them (control group) received no dietary supplement. Blood samples were taken before and after the training period. The following parameters were measured: ROMs, superoxide anion (O2⁻₂), malondialdehyde (MDA), advanced oxidation protein products (AOPP), lipid hydroperoxide (LOOH), biological antioxidative potential (BAP), paraoxonase activity toward paraoxon (POase) and diazoxon (DZOase), superoxide dismutase(SOD), total sulfydryl group concentration (SH groups), and lipid status. Reactive oxygen metabolites were taken as the dependent variable and MDA, O2⁻₂, AOPP, and LOOH as independent variables. In the group of athletes who have received supplementation, linear regression analysis revealed that the implemented model had a lower influence on dROMs (70.4 vs. 27.9%) after the training period. The general linear model showed significant differences between parameters before and after training/supplementation (Wilks' lambda = 0.074, F = 11.76, p < 0.01). At the partial level, significant increases in ROM levels (p <0.05, 95% confidence interval [CI]: 286-337), SOD activity (CI: 113-144), and BAP (CI: 2,388-2,580) (p < 0.01) were observed. The association between ROMs and other parameters of oxidative stress was reduced in athletes who received supplements. During the precompetition training period, treatment with dietary supplements prevented the depletion of antioxidative defense in volleyball athletes.

This study investigated the effects of a 6-week combined electromyostimulation (EMS) and gymnastic training program on muscle strength and vertical jump performance of prepubertal gymnasts. Sixteen young women gymnasts (age 12.4 ± 1.2 yrs) participated in this study, with 8 in the EMS group and the remaining 8 as controls. EMS was conducted on knee extensor muscles for 20 minutes 3 times a week during the first 3 weeks and once a week during the last 3 weeks. Gymnasts from both groups underwent similar gymnastics training 5-6 times a week. Isokinetic torque of the knee extensors was determined at different eccentric and concentric angular velocities ranging from -60 to +240° per second. Jumping ability was evaluated using squat jump (SJ), counter movement jump (CMJ), reactivity test, and 3 gymnastic-specific jumps. After the first 3 weeks of EMS, maximal voluntary torque was increased (+40.0 ± 10.0%, +35.3 ± 11.8%, and +50.6 ± 7.7% for -60, +60, and +240°s⁻¹, respectively; p < 0.05), as well as SJ, reactivity test and specific jump performances (+20.9 ± 8.3%, +20.4 ± 26.2% and +14.9 ± 17.2% respectively; p < 0.05). Six weeks of EMS were necessary to improve the CMJ (+10.1 ± 10.0%, p < 0.05). Improvements in jump ability were still maintained 1 month after the end of the EMS training program. To conclude, these results first demonstrate that in prepubertal gymnasts, a 6-week EMS program, combined with the daily gymnastic training, induced significant increases both in knee extensor muscle strength and nonspecific and some specific jump performances.

Maximal oxygen uptake (VO₂max) has been traditionally used to explain physiologic differences among soccer teams of different ranking. However, other endurance markers may have greater discriminatory ability. The purpose of this study was to examine whether velocity at lactate threshold and running economy can be used to better discriminate endurance characteristics of soccer teams of different levels along with VO₂max during preseason testing. One hundred twenty-nine professional Greek soccer players participating in the top 3 divisions underwent an incremental treadmill test to exhaustion using expired gas analysis and simultaneous blood lactate measurements. Velocity at lactate threshold was determined using the Dmax method, and running economy was measured at 12 km·h⁻¹. Analyses of variation were used to compare for differences between divisions. Velocity at lactate threshold was the only variable that was statistically different between any 2 divisions. In every comparison, the higher division had the higher velocity at lactate threshold. The VO₂ was statistically different only between the top 2 divisions. Running economy was statistically different between divisions with similar VO₂, with better running economy for the higher division in each comparison. These results indicate that velocity at lactate threshold can be used to better discriminate endurance characteristics of soccer teams of different level along with VO₂max during preseason testing. Running economy may reveal differences between teams with similar VO₂max.

We investigated in 27 male Ironman triathletes aged 30.3 (9.1) years, with 77.7- (9.8) kg body mass, 1.78- (0.06) m body height, 24.3- (2.2) kg·m⁻² body mass index (BMI), and 14.4 (4.8) % body fat and in 16 female Ironman triathletes aged 36.6 (7.0) years, with 59.7- (6.1) kg body mass, 1.66- (0.06) m body height, 21.5 (1.0) kg·m⁻² BMI, and 22.8 (4.8) % body fat to ascertain whether anthropometric or training variables were related to total race time. The male athletes were training 14.8 (3.2) h·wk⁻¹ with a speed of 2.7 (0.6) km·h⁻¹ in swimming, 27.3 (3.0) in cycling, and 10.6 (1.4) in running. The female athletes trained for 13.9 (3.4) h·wk⁻¹ at 2.1 (0.8) km·h⁻¹h in swimming, 23.7 (7.6) km·h⁻¹ in cycling, and 9.0 (3.7) km·h⁻¹ in running, respectively. For male athletes, percent body fat was highly significantly (r² = 0.583; p < 0.001) associated with total race time. In female triathletes, training volume showed a relationship to total race time (r² = 0.466; p < 0.01). Percent body fat was unrelated to training volume for both men (r² = 0.001; p > 0.05) and women (r² = 0.007; p > 0.05). We conclude that percent body fat showed a relationship to total race time in male triathletes, and training volume showed an association with total race time in female triathletes. Presumably, the relationship between percent body fat, training volume, and race performance is genetically determined.