The effects of plyometric jump training on jumping and swimming performances in prepubertal male swimmers

Swimming performance can be improved not only by in-water sport-specific training but also by means of dry land-training (e.g., plyometric jump training [PJT]). This study examined the effects of an 8-week PJT on proxies of muscle power and swimming performance in prepubertal male swimmers. Participants were randomly allocated to a PJT group (PJT; n=14; age: 10.3 ± 0.4 years, maturity-offset =-3±0.3) or a control group (CG; n=12; age: 10.5 ± 0.4 years, maturity-offset =-2.8±0.3). Swimmers in PJT and CG performed 6 training sessions per week. Each training session lasted between 80 and 90 minutes. Over the 8 weeks in-season training period, PJT performed two PJT sessions per week, each lasting between 25 to 30 minutes (1 hour per week) in replacement of sport-specific swimming drills. During that time, CG followed their regular sport-specific swimming training (e.g., coordination, breathing, improving swimming strokes). Overall training volume was similar between groups. Pre- and post training, tests were conducted to assess proxies of muscle power (countermovement-jump [CMJ]), standing-long-jump [SLJ]) and sport-specific swimming performances (15-, 25-, and 50-m front-crawl, 25-m kick without push [25-m kick WP], and 25-m front-crawl WP). No training or test-related injuries were detected over the course of the study. Between-group analyses derived from magnitude-based inferences showed trivial-to-large effects in favour of PJT for all tests (ES=0.28 to 1.43). Within-group analyses for the PJT showed small performance improvements for CMJ (effect-size [ES] =0.53), 25-m kick WP (ES=0.25), and 50-m front crawl (ES=0.56) tests. Moderate performance improvements were observed for the SLJ, 25-m front-crawl WP, 15-m and 25-m front-crawl tests (ES=0.95, 0.60, 0.99, and 0.85, respectively). For CG, the within-group results showed trivial performance declines for the CMJ (ES=-0.13) and the 50-m front-crawl test (ES=-0.04). In addition, trivial-to-small performance improvements were observed for the SLJ (ES=0.09), 25-m 26 kick WP (ES=0.02), 25-m front-crawl WP (ES=0.19), 25-m front-crawl (ES=0.2), (SLJ [ES=0.09, and 15-m front crawl (ES=0.36). Short-term in-season PJT, integrated into the regular swimming training, was more effective than regular swimming training alone in improving jump and sport-specific swimming performances in prepubertal male swimmers

Allometric associations between body size, shape, and 100-m butterfly speed performance

This study aimed to estimate the optimal body size, limb--segment length, and girth or breadth ratios associated with 100--m butterfly speed performance in swimmers

Key somatic variables in young backstroke swimmers

The purpose of this study was to estimate the optimal body size, limb-segment length, girth or breadth ratios for 100-m backstroke mean speed performance in young swimmers. Sixty-three young swimmers (boys [n = 30; age: 13.98 ± 0.58 years]; girls [n = 33; age: 13.02 ± 1.20 years]) participated in this study. To identify the optimal body size and body composition components associated with 100-m backstroke speed performance, we adopted a multiplicative allometric log-linear regression model, which was refined using backward elimination. The multiplicative allometric model exploring the association between 100-m backstroke mean speed performance and the different somatic measurements estimated that biological age, sitting height, leg length for the lower-limbs, and two girths (forearm and arm relaxed girth) are the key predictors. Stature and body mass did not contribute to the model, suggesting that the advantage of longer levers was limb-specific rather than a general whole-body advantage. In fact, it is only by adopting multiplicative allometric models that the abovementioned ratios could have been derived. These findings highlighted the importance of considering somatic characteristics of young backstroke swimmers and can help swimming coaches to classify their swimmers and enable them to suggest what might be the swimmers’ most appropriate stroke (talent identification)

Validity of a new sport-specific endurance test in artistic gymnastics

IntroductionGeneral and particularly sport-specific testing is an integral aspect of performance optimization in artistic gymnastics. In artistic gymnastics, however, only non-specific field tests have been used to assess endurance performance (e.g., Multistage Shuttle Run Test; Cooper's Test).MethodsThis study aimed to examine the validity of a new sport-specific endurance test in artistic gymnastics. Fourteen elite-level gymnasts (i.e., eight males and six females) participated in this study. The newly developed artistic gymnastics-specific endurance test (AGSET) was conducted on two different occasions seven days apart to determine its reliability. To assess the concurrent validity of AGSET, participants performed the multistage shuttle run test (MSRT). Maximum oxygen uptake (VO2max) and respiratory exchange ratio (RER) were directly assessed using a portable gas analyzer system during both protocols. Additionally, the total time maintained (TTM) during the AGSET, maximum heart rate (HRmax), maximal aerobic speed (MAS), and blood lactate concentration (BLa) during the two protocols were collected.ResultsThe main findings indicated that all variables derived from the AGSET (i.e., VO2max, MAS, HRmax, BLa, and RER) displayed very good relative (all intraclass correlation coefficients [ICC] > 0.90) and absolute (all typical errors of measurement [TEM] < 5%) reliability. Further, results showed that the ability of the AGSET to detect small changes in VO2max, MAS, BLa, and RER was good (smallest worthwhile change [SWC0.2] > TEM), except HRmax (SWC0.2 < TEM). Additionally, results showed a nearly perfect association between the VO2max values derived from the AGSET and MSRT (r = 0.985; coefficient of determination [R²] = 97%) with no statistically significant differences (p>0.05). The mean (bias) ± 95% limits of agreement between the two protocols were 0.28 ± 0.55 mlminkg-1.DiscussionAGSET seems to present very good reliability and concurrent validity for assessing endurance performance in elite artistic gymnastics. In addition, the newly developed protocol presents a good ability to detect small changes in performance

Key anthropometric variables associated with front-crawl swimming performance in youth swimmers: an allometric approach

This is an accepted manuscript of an article published by Lippincott, Williams & Wilkins/National Strength and Conditioning Association in Journal of Strength and Conditioning Research on 07/02/2020, available online: 10.1519/JSC.0000000000003491 The accepted version of the publication may differ from the final published version.Sammoud, S, Negra, Y, Chaabene, H, Bouguezzi, R, Attia, A, Granacher, U, Younes, H, and Nevill, AM. Key anthropometric variables associated with front-crawl swimming performance in youth swimmers: an allometric approach. J Strength Cond Res XX(X): 000-000, 2020-This study aimed to establish key anthropometric characteristics (e.g., optimal body height, limb-segment length, and girth/breadth ratios) related to 100-m front-crawl performance in young swimmers. In total, 74 swimmers (boys [n = 41; age: 18.1 ± 3.5 years]; girls [n = 33; age: 15.9 ± 3.1 years]) participated in this study. We adopted a multiplicative allometric log-linear regression model to identify key anthropometric characteristics associated with 100-m front-crawl swimming performance. The main outcomes indicated that length ratio = ([height/leg length]), foot length and ankle girth, biacromial breadth, and % of body fat were associated with 100-m front-crawl mean swimming speed performance. These findings highlight the importance of assessing anthropometric characteristics in young front-crawl swimmers for talent identification and development.Published versio

Effects of jump exercises with and without stretch-shortening cycle actions on components of physical fitness in prepubertal male soccer players

Objective: This study examined the effects of 8 weeks stretch-shortening-cycle-based (SSC-based) versus non-SSC-based jump exercises on physical fitness in prepubertal male soccer players. Methods: Twenty-six participants were randomly assigned to either a SSC-based using countermovement-jump (CMJG; n=13) or a non-SSC-based jump group using squat-jump (SJG; n=13). Pre- and post-training, tests were conducted to assess measures of muscle power (countermovement-jump, reactive-strength-index), speed (5-m, 20-m), change-of-direction (CoD), and sport-specific performance (maximal-kicking-distance). To establish the effect of the interventions on the dependent variables, a 2 (group: CMJG and SJG) × 2 (time: pre, post) ANOVA with repeated measures was determined for each parameter. Results: Findings demonstrated a main effect of time for countermovement-jump, reactive-strength-index, and maximal-kicking-distance (p0.05; ES=0.05). Conclusion: Overall, jump exercises which utilise the SSC seem to be more effective in improving measures of speed and muscle power performance in young athletes. However, jump exercises that do not involve the SSC appear to negatively affect CoD performance in young athletes

Why Flexibility Deserves to Be Further Considered as a Standard Component of Physical Fitness: A Narrative Review of Existing Insights from Static Stretching Study Interventions

The utility of flexibility as a standard component of physical fitness has recently been questioned, sparking a heated debate among scientists. More specifically, it has recently been proposed to retire flexibility as a major component of physical fitness and as a result de-emphasis stretching from exercise prescriptions. The aim of this narrative review was to summarize and discuss the most recent evidence related to the chronic effects of static stretching (SS) on muscle strength, muscle power, muscle hypertrophy, and injury prevention in healthy individuals. A literature search was conducted using the electronic databases PubMed, SPORTDiscus, Web of Science, and Google Scholar up to November 2022. We only considered studies written in English that addressed the chronic effects of SS exercises on flexibility, muscle strength, muscle power, muscle hypertrophy, or injury prevention in healthy individuals. With reference to the existing knowledge, we concluded that flexibility deserves to be further considered as a standard component of physical fitness. This is based on the findings that in addition to flexibility, long-term SS training induces positive effects on muscle strength, muscle power, and muscle hypertrophy, irrespective of age and sex. There are also indications that long-term SS training could mitigate the risk of injury, although this remains a debatable topic. Furthermore, promising evidence shows that combining resistance training with SS exercises constitutes an effective approach benefiting muscle strength and hypertrophy more than resistance training alone. In conclusion, we would not support the recent suggestion that flexibility should be retired as a standard component of physical fitness and we would advocate for a continuous emphasis on the prescription of stretching exercises

Effects of a horizontal speed deceleration training programme on measures of physical fitness in youth male handball players.

This study examined the effects of an 8-week horizontal speed deceleration training (HSDT) programme in combination with regular handball-specific training as compared with handball-specific training only in measures of physical fitness in male youth handball players. Thirty-nine players were randomly assigned to either an HSDT group (n = 18; 15.55 ± 0.24 years) or an active-control group (CG; n = 21; 14.59 ± 0.23 years). The results showed significant and large between-group differences at post-test in countermovement jump, change-of-direction speed, and repeated sprint ability (RSA) (all p best, RSAaverage, and RSAtotal performances, respectively). The post-hoc-analysis demonstrated significant and large improvements in all measures of physical fitness in the HSDT group (∆2.49% to 16,25%; d = 1.01 to 1,70; all p p = 0.379; p > 0.05). To summarise, an 8-week in-season HSDT programme alongside regular handball-specific training yielded positive effects on various performance measures including jumping ability, CoD speed, and RSA, when compared to handball-specific training alone. These results highlight the potential benefits of integrating HSDT into the training regimen of youth handball athletes during the competitive season

The effects of repeated sprint training with vs. without change of direction on measures of physical fitness in youth male soccer players

BACKGROUND: Fitness characteristics such as linear sprinting, repeated sprint ability, and change of direction (CoD) are important for male youth soccer players to maximize training safety and physical performance. We aimed to compare the effects of a 9-week repeated sprint training (RST) program, with and without change of direction (CoD) movements, on repeated sprint ability (RSA total time [RSAtotal], RSA best time [RSAbest]), CoD speed (505 CoD test), linear sprint speed (10-m and 20-m linear sprint), and aerobic endurance (AE; Yo-Yo intermittent endurance test level 1) in male youth soccer players. METHODS: During the in-season period, 20 soccer players were randomly assigned to a RST with CoD (RSTCoD) group (n = 10, age = 15.4±0.4 years) or a repeated linear sprint training group (n = 10, age = 15.6±0.3 years). Both training groups completed approximately two 15 minutes RST sessions per week, with the only difference between training programmes being the inclusion of one CoD movement during sprint repetitions for the RSTCoD group. RESULTS: The two-way ANOVA with repeated measures revealed a significant, moderate effect of time for RSAbest and RSAtotal (effect size [d] = 0.69 and 0.67, respectively). Likewise, significant, moderate-to-large effects of time were found for CoD (d=0.83), 10-m and 20-m sprint (d=0.68 and 0.67, respectively), and AE (d=0.66). No significant group × time interactions were observed for any measure of physical fitness (d=0.00 to 0.16). CONCLUSIONS: RST with and without CoD movements is equally effective in improving RSA total and best time, CoD speed, linear sprint speed, and AE in youth male soccer players

Effects of plyometric jump training on measures of physical fitness and lower-limb asymmetries in prepubertal male soccer players: a randomized controlled trial

Abstract Background High level of physical fitness is a paramount soccer performance factor. As such, developing key components of physical fitness such as sprinting, jumping, and change of direction (CoD) at an early age empowers both short- and long-term performance success. Although previous research in prepubertal male soccer players has reported physical fitness performance enhancements following plyometric jump training (PJT), the effects on inter-limb asymmetries remain unclear. Objective To assess the effects of PJT on measures of physical fitness and inter-limb asymmetries in prepubertal male soccer players. Methods A total of 27 participants were recruited, and randomly assigned to either a PJT group (n = 13; age = 12.7 ± 0.2 years; maturity offset = -1.6 ± 0.7) or an active control group (CG) (n = 14; age = 11.8 ± 0.4 years; maturity offset = -2.51 ± 0.61). The training intervention lasted eight-week and was conducted during the in-season period, with twice-weekly sessions. Physical fitness tests were conducted before and after the intervention, including the 505 change-of-direction (CoD; [505 CoD test]), countermovement-jump (CMJ) height, standing-long-jump (SLJ) distance, and single-leg hop test for distance with dominant (SHTD-D) and non-dominant legs (SHTD-ND). A jump-based asymmetry score was calculated as the difference between HTD and HTND. Results ANCOVA analysis revealed significant between-group differences in all physical fitness measures at post-test. Specifically, the PJT group showed significant large improvements in CMJ height, SLJ distance, HTD and HTND, and CoD speed (d = 0.84 to 2.00; ∆1.05% to 16.85%). Moreover, the PJT group showed a significant, small reduction in the inter-limb asymmetry score (d = 0.43; ∆-45.21%). In contrast, no significant changes were reported in the CG between pre-and post-tests (d = 0.07 to 0.24; ∆0.21% to 0.98%). Conclusions The incorporation of PJT into the training schedules of prepubertal male soccer players resulted in positive effects on various measures of physical fitness. Furthermore, our findings suggest that PJT can reduce lower-limb asymmetry, which could potentially decrease the risk of lower limb injuries. Trial registration This study does not report results related to healthcare interventions using human participants and therefore it was not prospectively registered