20-m Sprint Time Research Articles

Relationships Between Functional Movement Quality and Sports Performance in Elite Figure Skating Athletes of China.

Zhitao, L, Junlong, D, Rui, Y, Leijiao, Y, Cheng, G, and Jun, Y. Relationships between functional movement quality and sports performance in elite figure skating athletes of China. J Strength Cond Res 38(11): e678-e685, 2024-This study aimed to determine the optimal functional movement screen (FMS) cut score for assessing the risk of sports injuries and to explore the correlations between functional movement quality and sports performance among elite figure skaters. A total of 22 elite figure pairs skaters in China underwent FMS, sports performance, and clinical examinations for sports injuries. The FMS cut score was determined using the receiver operating characteristic curve. Pearson's rank correlation analysis was used to quantify associations between the variables. (a) The optimal FMS cut score for assessing the risk of sports injuries was 13 (p = 0.008), with an area under curve of 0.838. The sensitivity and specificity were 0.889 and 0.692, respectively. (b) The trunk stability push-up (TSPU), an individual FMS test, predicted injuries in figure skaters (p = 0.015). (c) Moderate correlations were found between shoulder mobility and bench strength (r = -0.453, p = 0.034), counter movement jump (r = -0.582, p = 0.007), and 30-m sprint (r = 0.567, p = 0.009). A strong correlation was observed with squat jump (r = -0.774, p = 0.001). In addition, TSPU scores moderately correlated with 30-m sprint times (r = -0.511, p = 0.021) and 30-s average anaerobic power (r = 0.503, p = 0.024). These findings indicate that both the FMS total score ≤13 and the FMS individual score serve as indicators of injury risk in figure skaters. However, only the FMS individual score reflected the sports performance. This likely results from the similarity in kinetic chain systems and movement patterns involved in both the FMS individual test and sports performance, suggesting a promising assessment strategy for sports performance.

Effects of 2 Combined Training Protocols on the Aerobic and Anaerobic Fitness, Technical Skills, and Psychophysiological Responses in Young Soccer Players.

Kilit, B, Chmura, P, Arslan, E, Soylu, Y, and Radziminski, Ł. Effects of 2 combined training protocols on the aerobic and anaerobic fitness, technical skills, and psychophysiological responses in young soccer players. J Strength Cond Res XX(X): 000-000, 2024-The study compared the effects of combining small-sided soccer games (SSGs) with high-intensity interval training (HIIT) and repeated sprint training (RST) on aerobic and anaerobic fitness, technical skills, and psychophysiological responses in young soccer players. Thirty-two male, adolescent, soccer players (aged 13.5 ± 0.3 years) were randomly divided into either the SSGs + HIIT group ( n = 16) or the SSGs + RST group ( n = 16) for combined training 3 times per week for 6 weeks. The players in the SSGs + HIIT group performed 12-18 minutes of runs at intensities (90-95%), whereas the players in the SSGs + RST group consisted of 3-4 sets of 5-7 times 15-m shuttle sprints (all-out efforts). Both training groups played 4 bouts of 2-a-side or 4-a-side SSGs with various game formats at 2-day intervals. Psychophysiological responses were determined during and after all training sessions. Before and after training interventions, the following physical performance tests were used: 5- to 30-m sprint time, countermovement jump, triple-hop distance, zigzag agility with the ball and without the ball, repeated sprint ability (RSA), 30-15 Intermittent Fitness Test, 3 corner run test, speed dribbling ability (SDA), Yo-Yo Intermittent Recovery Test Level 1, and Y-balance test. Our main findings were that the SSGs + RST group demonstrated greater improvement in 5-m sprint time, SDA time, and RSA in the meantime compared with the SSGs + HIIT ( p ≤ 0.05, d values ranging from 1.50 to 2.25). Moreover, the SSGs + RST group showed greater improvement in agility test responses ( p ≤ 0.05, d values ranging from 2.13 to 2.34) than the SSGs + HIIT group. However, the SSGs + HIIT induced higher perceived exertion, mental effort, and lower greater physical enjoyment meaningfully compared with the SSGs + RST ( p ≤ 0.05, d values ranging from 6.04 to 6.67). In conclusion, these results demonstrate that the SSGs + RST is an effective training program to improve young soccer players' speed and agility-based performance responses.

The relationship between maximal lactate accumulation rate and sprint performance parameters in male competitive swimmers.

This study aimed to examine the relationship between the maximal lactate accumulation rate (ċLamax) and sprint performance parameters in male competitive swimmers. Seventeen male competitive swimmers volunteered to perform a 20 m maximal front crawl sprint without pushing off the wall from a floating position. ċLamax was determined by the 20-m sprint time and blood lactate measured before and after the 20 m sprint. For the sprint performance parameter, a 50 m time trial with the front crawl swimming stroke was conducted, and the times taken from 0 to 15 m, 15-25 m, 25-35 m, and 35-45 m were analyzed. A semi-tethered swimming test was conducted to investigate the load-velocity profile of each swimmer. From the load-velocity profile, theoretical maximal velocity (V0), maximal load (L0) and relative maximal load (rL0) were examined. The slope of the load-velocity profile was also determined. According to the results, ċLamax correlated with 50 m front crawl performance (r = -.546, p < .05). Moreover, a higher ċLamax was related to faster 0-35 m section time. Furthermore, ċLamax correlated with L0 (r = .837, p < .01), rL0 (r = .820, p < .01), and load-velocity slope (r = .804, p < .01). ċLamax is a good indicator of 50 m front crawl performance in male swimmers, and higher glycolytic power contributes to the faster time at the beginning of the sprint race. ċLamax could also evaluate the ability of a swimmer to apply force to the water during high-intensity swimming.

THE POST-ACTIVATION EFFECT OF COMBINED RESISTED AND ASSISTED SPRINTS

Resisted and assisted training methods aim to increase neural activation, or post-activation potentiation (PAP), to enhance sprint performance. A preloaded stimulus causes a temporary performance increase that is more significant than what warm-up alone can provide. Resistance activities have traditionally been used to induce post-activation potentiation. Little is known when assisted and resisted sprints are combined and their effect on PAP. Therefore, this study aimed to examine the acute potentiating effect of combined resisted and assisted sprints on subsequent 20 m sprint performance. Sixteen physically active young males performed a baseline 20 m sprint followed by four assisted 20 m and four 20 m resisted sprints using a bungee cord. After the assisted-resisted stimulus, the participants performed one 20 m sprint at 4, 6, and 8 minutes. There was no significant improvement in 5, 10, or 20-m sprint times following the assisted-resisted stimulus. Therefore, the additive effect of assisted-resisted sprints failed to induce post-activation potential. The additive effect of assisted-resisted sprints could not induce post-activation potential to enhance subsequence sprint performance.

Feasibility and Effects of a Neuromuscular Warm-Up Based on the Physical Literacy Model for 8-12-Year-Old-Children

ABSTRACT Background: Physical literacy and injury prevention strategies use similar movement-related constructs and can be connected to develop comprehensive interventions. We aimed to test the feasibility and effects of a neuromuscular warm-up based on physical literacy and injury prevention strategies for 8–12-year-old children. Methods: We conducted a cluster non-randomized controlled trial. We defined a priori feasibility criteria and studied the effects of the intervention on physical literacy constructs, movement competence, and neuromuscular performance. We used generalized linear mixed models controlling for covariates and clustering with a significance level of 0.001. Results: We recruited 18 groups (n = 363) and randomly allocated nine to intervention (n = 179; female = 63.7%, age = 9.8 ± 1 years) and nine to control (n = 184, female = 53.3%, age = 9.9 ± 0.9 years). We met four of seven feasibility criteria (i.e. recruitment, adherence, enjoyment, perceived exertion). The three feasibility criteria that were not met (i.e. compliance, fidelity, follow-up) were slightly below the predefined threshold (90%). Model-adjusted mean differences for physical literacy constructs, movement competence, vertical jump height, horizontal jump distance, 20-m sprint time, and dynamic balance favored the intervention (p < .001). Conclusion: The feasibility evidence indicates that the intervention should be slightly modified before implementing it in a larger study. The observed mean differences are promising and can be used in planning future interventions.

Microdosing Plyometric Training Enhances Jumping Performance, Reactive Strength Index, and Acceleration among Youth Soccer Players: A Randomized Controlled Study Design.

Microdosing can facilitate better accommodation to the training stimulus while aligning with the scheduling needs of teams. In this study, the effectiveness of microdosing exposure was investigated by comparing the effects of microdosing plyometric jump training (microPJT) with those of regular plyometric jump training (regPJT) and a control group not exposed to plyometric training. The comparison focused on the effects on jumping performance, reactive strength index (RSI), and acceleration over a 10-meter distance. Fifty-two male youth soccer players (16.3 ± 0.6 years old) from under-17 teams participated in a randomized controlled study, with interventions lasting 8 weeks. Assessments were conducted twice, before and after the intervention, measuring squat jump (SJ), countermovement jump (CMJ), RSI during drop jumps, and acceleration in a 10-meter sprint test. The regPJT group completed 34 bilateral jumps and 48 unilateral jumps per week over two weekly sessions, totaling 82 jumps. Conversely, the microPJT group performed 17 bilateral jumps and 24 unilateral jumps weekly over 4 sessions week, totaling 41 jumps. Significant interactions between groups and time were observed concerning SJ (p < 0.001; η2= 0.282), CMJ (p < 0.001; η2= 0.368), RSI (p < 0.001; η2= 0.400) and 10-m sprint time (p < 0.001; η2 = 0.317). Between-group analysis indicated that both the microPJT (p < 0.001) and regPJT (p < 0.001) groups exhibited significant better results compared to the control group in post-intervention evaluation of SJ, CMJ, RSI and 10-m sprint time, while no significant differences were found between experimental groups (p > 0.050). In conclusion, this study has revealed that both microPJT and regPJT are equally effective in enhancing jumping performance and acceleration time in soccer players. This suggests that a smaller training volume, distributed more frequently across the week, can effectively induce improvements in soccer players.

Advancing 100m sprint performance prediction: A machine learning approach to velocity curve modeling and performance correlation.

This study presents a novel approach to modeling the velocity-time curve in 100m sprinting by integrating machine learning algorithms. It critically addresses the limitations of traditional speed models, which often require extensive and intricate data collection, by proposing a more accessible and accurate method using fewer variables. The research utilized data from various international track events from 1987 to 2019. Two machine learning models, Random Forest (RF) and Neural Network (NN), were employed to predict the velocity-time curve, focusing on the acceleration phase of the sprint. The models were evaluated against the traditional exponential speed model using Mean Squared Error (MSE), with the NN model demonstrating superior performance. Additionally, the study explored the correlation between maximum velocity, the time of maximum velocity occurrence, the duration of the maximum speed phase, and the overall 100m sprint time. The findings indicate a strong negative correlation between maximum velocity and final time, offering new insights into the dynamics of sprinting performance. This research contributes significantly to the field of sports science, particularly in optimizing training and performance analysis in sprinting.

Effects of vertical and horizontal plyometric training on jump performances and sprint force-velocity profile in young elite soccer players.

During a soccer match, horizontal acceleration ability during short sprints is determinant for performance. Development of sprint force and velocity qualites have been reported after plyometric training. However, orientation of plyometric training exercises can influence the functional performance. The purpose of this study was to compare the horizontal and vertical orientation of plyometric training on explosiveness performances and sprint force-velocity profile in young soccer players. Twenty-eight soccer players were recruited and divided in two groups: vertical (VG, n = 14) and horizontal (HG, n = 14) groups. Tests including jumps and sprint performances were conducted before and after the 8week training period. Sprint force-velocity profile (FVP) was evaluated during a 30m sprint test. The results demonstrated significant improvements in both VG and HG for jump performances (from + 4.9% to + 9.0%), sprint times (from -5.5% to -8.7%) and FVP parameters. Higher relative changes for the HG than for the VG were observed in 5m and 15m sprint times, horizontal jump lengths, and also in FVP parameters, especially improvements in maximal power (VG: + 16.4% vs. HG: + 28.1%) and inthe decrease rate of horizontal orientation of force with increasing speed (HG: + 22.9%) during the 30m sprint. Both horizontal and vertical plyometric training can be either used in young soccer players to improve vertical and horizontal performances in jump and sprint. However, horizontal plyometric training may result in a greater improvement in horizontal ballistic actions while similarly developing vertical jump qualities compared to vertical plyometric training in young soccer players.

Influence of Vertical-Oriented vs. Horizontal-Oriented Combined Strength Training in Young Basketball Players.

Sánchez-Sabaté, J, Gutiérrez, H, Marco-Contreras, LA, Younes-Egana, O, Gonzalo-Skok, O, and Piedrafita, E. Influence of vertical-oriented vs. horizontal-oriented combined strength training in young basketball players. J Strength Cond Res 38(7): 1280-1287, 2024-This study aimed to compare the effects of 8-week combined vertical-oriented vs. horizontal-oriented training interventions in basketball athletes. Eighteen highly trained U-16 basketball players participated in this study and were randomly assigned to either a combined vertical-oriented training group (CVG, n = 9) or a combined horizontal-oriented training group (CHG, n = 9). Bilateral and unilateral vertical jump height, unilateral horizontal jump distance, 5-m, 10-m, and 20-m sprint times, change-of-direction sprint times, and a limb symmetry index were among the measured performance variables. Combined strength training was performed twice a week for 8 weeks. CVG was compounded by the squat exercise (3 sets of 6-8 R at 30-45% 1 repetition maximum [1RM]), jump squats (2 sets of 6 R, at 5-12.5% body mass [BM]), and vertical jumps (3-4 sets × 6 R). CHG included the hip thrust exercise (3 sets of 6-8 R at 30-45% 1RM), sled towing sprints (2-3 R, at 5-12.5% BM), and sprints (3-4 R of 20-m). Within-group differences showed significant ( p < 0.05 and statistical power >80%) improvements in unilateral vertical jumping with the right leg after both training interventions. By contrast, only CHG improved 5-m, 10-m, and 20-m sprint times ( p < 0.05 and statistical power >80%). Significant effects were observed for CHG compared with CVG in 5-m, 10-m, and 20-m sprint times ( p < 0.05 and statistical power >80%). This study reinforces the importance of oriented-combined training based on force-vector specificity target, mainly in horizontal-oriented actions.

Comparison of physical fitness and game demands between young female rugby sevens athletes in different sports development contexts

Aim: This study aimed to compare the physical and game demands among young women rugby sevens athletes inserted in a long-term athlete development process (LTAD) and selected to the national team. Methods: Twenty-four athletes were recruited in two different contexts: thirteen participants were inserted in the LTAD process (VSR) and eleven Brazilian athletes were selected for the youth national team (BRA). One-repetition-maximum tests, jumping performance, sprint times, and aerobic capacity determined the physical performance and GPS recorded the game demands in the national championship. T-tests for independent samples and Mann-Whitney were used to compare the groups, and effect size (ES) was presented using Cohen's d. Results: 10-m sprint time (p = 0.001; ES = 1.47), 30-m sprint time (p = 0.005; ES = 1.42), sprint distance (p = 0.030; ES = 1.14) and distance in zone 5 (p = 0.040; ES = 0.92) showed differences between groups, with better results in BRA. Moreover, VSR athletes covered greater distances in zone 1 while BRA had greater distances in zone 4, with moderate ES. The strength, power of lower limbs, and aerobic fitness variables did not present significant differences between the groups. However, VSR had the highest mean in squat jump and countermovement jump, with moderate ES. Conclusion: Speed in physical tests and game demands differentiated the groups, and these parameters are essential for selection for the national team. However, the LTAD process can bring physical

Effects of Plyometric Training on Physical Fitness Attributes in Handball Players: A Systematic Review and Meta-Analysis.

This meta-analysis aimed to examine the effects of plyometric training on physical fitness attributes in handball players. A systematic literature search across PubMed, SCOPUS, SPORTDiscus, and Web of Science identified 20 studies with 563 players. Plyometric training showed significant medium-to-large effects on various attributes: countermovement jump with arms (ES = 1.84), countermovement jump (ES = 1.33), squat jump (ES = 1.17), and horizontal jump (ES = 0.83), ≤ 10-m linear sprint time (ES = -1.12), > 10-m linear sprint time (ES = -1.46), repeated sprint ability with change-of-direction time (ES = -1.53), agility (ES = -1.60), maximal strength (ES = 0.52), and force-velocity (muscle power) (ES = 1.13). No significant impact on balance was found. Subgroup analysis indicated more pronounced agility improvements in players ≤ 66.6 kg compared to > 66.6 kg (ES = -1.93 vs. -0.23, p = 0.014). Additionally, greater improvements were observed in linear sprint and repeat sprint ability when comparing training durations of > 8 weeks with those ≤ 8 weeks (ES = -2.30 to -2.89 vs. ES = -0.92 to -0.97). In conclusion, plyometric training effectively improves various physical fitness attributes, including jump performance, linear sprint ability, maximal strength, muscle power and agility.

Muscle geometry and its relevance for sports performance? A perspective of current findings and future opportunities

Muscle geometry and its relevance for sports performance? A perspective of current findings and future opportunities

Chill Without Thrill: A Crossover Study on Whole-Body Cryotherapy and Postmatch Recovery in High-Level Youth Basketball Players.

To assess the effect of whole-body cryotherapy (WBC) on postmatch recovery in basketball. Using a crossover design, 17 youth male players (age 16.2 [1.2]y, stature 190.5 [9.4]cm, body mass 79.2 [9.6]kg, experience 9.9 [3.9]y) completed 2 simulated matches, followed by WBC (4min, -75 to - 85 °C) or a placebo intervention (CON). Countermovement-jump height, change-of-direction performance, 10- and 20-m sprint times, heart-rate variability (log-transformed squared root of the mean sum of the squared differences between R-R intervals [Ln-rMSSD]), muscle soreness, and perceived recovery (Perceived Recovery Status Scale [PRS]) were recorded at prematch, postmatch, postrecovery, and 24hours postmatch. Additionally, Ln-rMSSD was recorded upon awakening on match day and the following morning. Compared with CON, higher PRS values were reported in WBC at prematch and postrecovery (P ≤ .026), while no significant between-interventions differences were found for any other measure (P > .05). Regarding the effect of time, our findings revealed that 20-m sprint times, Ln-rMSSD, and PRS deteriorated in both interventions from prematch to postmatch (ie,acute changes, P ≤ .045), while muscle soreness worsened in WBC only (P ≤ .003). Conversely, countermovement-jump height, change-of-direction, and 10-m sprint performance were unaffected by match play in the acute phase (P > .05), while none of the investigated measures showed impairments at 24hours postmatch, compared with prematch (P > .05). Overall, these findings suggest that WBC was mostly ineffective for improving postexercise recovery in the investigated sample, with benefits observed for perceived recovery being potentially influenced by the participants' status at baseline (ie,higher prematch PRS scores in WBC compared with CON).

Are Young Female Basketball Players Adequately Prepared for a Force-Velocity Jumping and Sprinting Assessment?

The aim of this study was to explore the interday reliability of mechanical variables obtained from the horizontal and vertical force-velocity (FV) profiles in adolescent female basketball players. If found to be reliable, the associations between FV parameters (theoretical maximal force, velocity, and power), squat jump (SJ) height, 30-m sprint, and change of direction (COD) times were evaluated. After familiarization, SJ against incremental loads, 30-m sprint, and 505-COD tests were obtained twice in 36 adolescent female basketball players (age = 15.4 [1.2]y). Reliability for vertical FV parameters was unacceptable, whereas 505-COD times and FV horizontal parameters (except for theoretical maximal power) showed a moderate to high reliability. 505-COD time was correlated with FV horizontal parameters (range: r = -.821, -.451), and a large association was observed with both SJ height (r = -.678, -.600) and 30-m sprint time (r = .813, .858). Due to low levels of strength, our athletes were not adequately prepared to obtain a reliable vertical FV profile. Practitioners can expect acceptable reliability of the horizontal FV profile. Given the association between COD performance and SJ height and 30-m sprint time, we encouraged practitioners with limited equipment at their disposal to use COD and/or 30-m sprint tests.

Assessment of the Relationship Between Physical Performance and Percentage Change-of-Direction Deficit in Highly Trained Female Football Players.

Different studies indicate that female players in team sports such as soccer tend to have a lower change-of-direction (COD)deficit (CODD) than their male counterparts and that players who performed better in linear and curved sprints tended to have a worse CODD, suggesting that maximum speed does not equate to a faster COD. This study assessed how performance variables related to speed and jumping influence the variability of %CODD among adult highly trained female soccer players. Fifty-two highly trained female soccer players (age 23.1 [3.25]y; height 163.6 [5.49]cm; weight 59.7 [5.71]kg) participated in this study and performed 180COD, 40-m sprint, countermovement jump, and standing broad jump tests. Significant correlations were found between 180CODL, %CODDR, %CODDL, and between-limbs standing broad jump asymmetry (r = .28-.74). A very large correlation existed between %CODDR and %CODDL (r = .91). Regression analyses indicated a strong inverse relationship between the 10-m sprint time and %CODDR and %CODDL. No predictive models were found for 180COD in either limb. Differences in performance variables suchas 180CODR, 180CODL, and asymmetry %CODD were significant between the high- and low-%CODD groups, with moderate to large effect sizes. The present study suggests that specific physical-performance variables, particularly acceleration and unilateral horizontal jumping, are vital to improving COD in highly trained female soccer players, highlighting the need for specific training interventions.

The relationship between countermovement jump performance and sprinting speed in elite sprinters

Data regarding associations between vertical jumping and sprinting ability is lacking in elite sprinters. Therefore, the aim of this study was to evaluate relationship between variables such as countermovement jump (CMJ) height, relative peak power, and sprint time including flight time and ground contact time across various distances in the 50-m sprint among elite sprinters. Twenty- three male sprinters performed two CMJ attempts followed by two 50-m sprints on an indoor track. Jumping performance was assessed via force plates, while sprint times were recorded using timing photocells, with gates at 0, 5, 20, 30, and 50-m. Results showed a statistically significant negative correlations ranging from large to very large, between CMJ height and sprint time (p&lt;0.01; r= -0.56 to -0.73) across specific distances. Similarly, a significant large to very large correlations was found between CMJ relative peak power and sprint time (p&lt;0.01; r= -0.61 to -0.85) at the studied distances. Furthermore, a large significant correlations was indicated between sprint contact time and sprint time at certain distances (p&lt;0.01; r= -0.55 to 0.62), while sprint flight time correlated with distances above 20-m sprint time (p&lt;0.05; r= 0.45 to 0.48) and with the 20-50-m flying start sprint time (p&lt;0.05; r= 0.48), reaching a moderate magnitude. These findings suggest a significant negative correlation between relative peak power, CMJ height and sprint times across various distances, highlighting the potential for individualized training based on distinct sprint phases. Remarkably, the strength of these correlations increase with longer sprint distance.

Physical Determinants of Sprint and Long Jump Performance in Male Youth Track-and-Field Athletes With Differing Maturity Statuses.

This study examined the physical determinants of 60-m sprint and long jump (LJ) performance and differences between maturity groups in physical characteristics in young male track-and-field athletes. Competition results, countermovement jump, isometric leg press, 10-5 repeated jump test, and 50-m sprint were collected over 3 seasons for 54 male athletes (age 13 [1]y; stature 160.0 [8.9]cm; body mass, 48.0 [9.8]kg; percentage predicted adult height 92.2% [5.5%]) grouped by maturity status: approaching- (n = 16), circa- (n = 19), and post-peak height velocity (PHV) (n = 19). There were significant between-group differences in 60m, LJ, and all physical testing variables (P < .001, g = 0.88-5.44) when comparing the approaching- and circa-PHV groups with the post-PHV group. Significant differences were identified between the approaching- and circa-PHV groups in 40-m (P = .033, g = 0.89), 50-m (P = .024, g = 1.64), and 60-m (P < .001, g = 0.89) sprint times. Countermovement jump and 50-m sprint variables were consistently important for projection of 60m and LJ performance across the valid multivariate models. Large differences in performance across maturity groups highlight the importance of understanding athletes' maturity status to accurately interpret performance. Several physical performance variables were important for projecting competition 60m and LJ performance.

Normative Reference Centiles for Sprint Performance in High-Level Youth Soccer Players: The Need to Consider Biological Maturity.

To compute reference centiles for 5- and 30-m sprint times relative to chronological and skeletal age in youth soccer players. Subsequently, to compare individual's sprint performance scores derived from the chronological and skeletal age reference centiles. Sprint times were collected for a sample of male U11 to U19 soccer players (n = 1745 data points). Skeletal age data were available for a subsample (n = 776 data points). Reference centiles were fitted using generalized additive models for location, scale, and shape. Individual z scores relative to chronological and skeletal age reference centiles were computed and compared for each maturity group (late, on-time, early, and very early) using standardized mean differences (SMD). Reference centiles for chronological age increased more rapidly between 10.5 and 15.5years, while reference centiles for skeletal age increased more rapidly between 13.0 and 16.5years. Differences in chronological and skeletal z scores for very early (SMD: -0.73 to -0.43) and late (SMD: 0.58 to 1.29) maturing players were small to large, while differences for early (SMD: -0.30 to -0.19) and on-time (SMD: 0.16 to 0.28) were trivial to small. Reference centiles provide a valuable tool to assist the evaluation of sprint performance in relation to chronological and skeletal age for talent identification purposes in youth soccer players.

Anthropometric characteristics and 20-m sprint times among Malaysian University athletes

Introduction: The aim of this study was to evaluate the anthropometric characteristics of the Malaysian University level athletes and to explore potential relationships between the anthropometric measures and 20-m linear sprint performance. Method: Forty male Malaysian University level athletes associated with Malaysian Universities and regularly competing in state level competitions took part in the study. Anthropometric measurements were performed for body mass, stature, 8 skinfold sites, 3 girths, and 2 breadths. Somatotype, body fat % and sum of skinfolds were calculated. A 20-m linear sprint test was performed to assess acceleration and running speed. Results: The pairwise comparison analysis revealed that throwers had significant differences in endomorphy with athletes competing in sprinting, karate, and middle distance (p ˂ 0.05), in mesomorphy with athletes competing in long distance, middle distance, sprinters, footballers and karate (p ˂ 0.05), and in ectomorphy with athletes competing in middle distance and karate. The Pearson correlation coefficient between Body Fat Percent and Sprint Time was found to be 0.374 (p = 0.025, two-tailed), indicating a statistically significant positive correlation between the two variables. Conclusion: Physique is highly correlated with the physical characteristics and the development of the athletic functions required in each sport and is a determinant of success. Body fat percentage influences the ability of an individual to accelerate and run maximally.

The impact of COVID-19 pandemic isolation on the performance of track and field athletes: A comparative study of 100m sprint

The COVID-19 pandemic necessitated the suspension of schools and sports-related activities, leading to a disruption in athletes' engagement with sports training and subsequent negative effects on their performance. This research employs an experimental approach to investigate the influence of pandemic-induced isolation on the performance of track and field athletes in the 100m sprint. The study focuses on a sample of 60 athletes from elementary, secondary, and tertiary levels in Albay, Philippines. To assess performance, coaches provided data on the athletes' best time in the 100m sprint from 2019. Additionally, two sprint tests were conducted with the assistance of coaches to determine the current best time, with the lowest time recorded. Paired sample t-tests were employed to analyze the variation in 100m sprint times across different age groups, and sex comparing pre-pandemic and post-pandemic isolation periods. The statistical analysis revealed a significant difference between the two performance measures, as indicated by computed p-values consistently below the predetermined significance level of 0.05. To counteract this decline, the implementation of intensive and safe training environments is recommended, which would facilitate the gradual restoration of athletes' performance without compromising their health and well-being.