Effects of Equal Volume But Different Plyometric Jump Training Intensities on Components of Physical Fitness in Physically Active Young Males

Ramirez-Campillo, R, Moran, J, Drury, B, Williams, M, Keogh, JW, Chaabene, H, and Granacher, U. Effects of equal volume but different plyometric jump training intensities on components of physical fitness in physically active young males. J Strength Cond Res XX(X): 000–000, 2019—An 8-week single-blind randomized controlled trial was conducted to compare the effects of separate programs of equal volume, but different intensity, plyometric jump training (PJT), on physical fitness in healthy adults. Thirty-eight physically active males (mean age: 21.8 6 2.5 years) participated. Subjects were randomly assigned to one of 3 PJT groups or a control (CON, n = 9) according to their jump performance. Plyometric jump training was conducted at maximal (PJT-100, n = 10), high (PJT-80, n = 9), or moderate (PJT-65, n = 10) intensity within each group. Baseline and follow-up tests were performed for the assessment of countermovement jump (CMJ) height, CMJ height with arm swing (CMJA), and drop jump height from a 20-cm drop box (DJ20), linear speed (30 m), and change-of-direction speed (CODS) (the Illinois CODS test). Results revealed significant group 3 time interactions for CMJ, CMJA, DJ20, 30-m sprint, and CODS (all p , 0.001; d = 0.39–0.76). Post hoc analyses showed significant improvements in all 5 fitness measures for PJT-100 (all p , 0.01, D3.7–13.5%, d = 0.26–1.4). For PJT-80, 3 of 5 fitness tests demonstrated significant change (CMJ: p , 0.001, D5.9%, d = 0.33; CMJA: p , 0.001, D7.0%, d = 0.43; CODS: p , 0.001, D3.9%, d = 0.9), and for PJT-65, only 1 test was significant (CMJ: p , 0.05, D2.8%, d = 0.15). No significant changes were observed in CON. Except for similar gains in DJ20 and 30-m sprint in PJT-100 and PJT-80, gains in physical fitness were, in general, greater (p , 0.05) after PJT-100 vs. PJT-80 vs. PJT-65 vs. CON. Therefore, maximal PJT intensity may induce larger physical fitness gains, although high and moderate intensities may also be useful, but to a lesser exten

Can discreet performance banding, as compared to bio-banding, discriminate technical skills in male adolescent soccer players? A preliminary investigation

Maturation-related changes in body dimensions and performance can lead to physical mismatches and drop out fromyouth sport. Here, we propose a new method termed ‘discreet performance banding’ (DPB). We aimed to determine ifdividing youths byactualphysical performance of a discreet skill or ability (‘change or direction’ [COD] ability) coulddiscriminate between the most and least skilled players better than a marker ofimpliedperformance, such as anassessment of biological maturation. 182 male academy Spanish soccer players (age: 13-18 years height: 143 to188 cm; mass: 32.3 to 81.4 kg) were divided into maturation groups (Tanner stages 2 through 5) and COD groups(‘fast’, ‘intermediate’ and ‘slow’). Players’ skills (passing, shooting, ball control) were evaluated on a six-point scale with avalue of ‘1’ considered ‘very bad’ and a value of ‘6’ as ‘very good’. When divided by maturity status, analyses revealed nosignificant differences between groups in soccer skill. However, when divided into COD groups, the analyses revealedsignificant differences between the fast and intermediate players ([p<0.001] favouring the fast group) and between theintermediate and slow players ([p<0.026] favouring the slow group). There was no significant difference in skill betweenthe fast and slow groups, though the fast group demonstrated a higher skill level as indicated by a small effect size. Fastplayers were more skilful than both the intermediate and slower players, indicating that COD status can be a differ-entiating factor between players of different skill levels. DPB could be used to equalise competition in youth sport and toenhance the overall level of enjoyment that youths derive from engagement in sport

Influence of Maturation Status on Eccentric Hamstring Strength Improvements in Youth Male Soccer Players following the Nordic Hamstring Exercise

Purpose: This study examined the effects of a 6-week nordic hamstring exercise (NHE) program in youth male soccer players of less mature (Pre-Peak Height Velocity [PHV]) or more mature (Mid/Post-PHV) status. Methods: Forty-eight participants were separated into Pre-PHV (11.0 ± 0.9yrs) or Mid/Post-PHV (13.9 ± 1.1) groups and further divided into experimental (EXP) and control (CON) groups with eccentric hamstring strength assessed (Nordbord) both pre and post the training program. Participants in the EXP groups completed a periodised NHE program performed once or twice weekly over a 6-week period. Results: The NHE programme resulted in moderate and small increases in relative eccentric hamstring strength (N.kg-1) in the Pre-PHV EXP (d = 0.83 [0.03 - 1.68]) and Mid-PHV EXP (d = 0.53 [-0.06 - 1.12]) groups respectively. Moderate increases in the same measure were also seen in the between-group analyses in the Pre-PHV (d = 1.03 [0.23 - 1.84]) and Mid-PHV groups (d = 0.87 [0.22 - 1.51]), with a greater effect observed in the former. Conclusion: The results from this study demonstrate that a 6-week NHE program can improve eccentric hamstring strength in male youth soccer players with less mature players achieving mostly greater benefits. The findings from this study can aid in the training prescription of the NHE in youth male soccer players

Effects of Small-Sided Games vs. Conventional Endurance Training on Endurance Performance in Male Youth Soccer Players: A Meta-Analytical Comparison

This paper is in closed access .© 2019, Springer Nature Switzerland AG. Background: Small-sided games have been suggested as a viable alternative to conventional endurance training to enhance endurance performance in youth soccer players. This has important implications for long-term athlete development because it suggests that players can increase aerobic endurance through activities that closely resemble their sport of choice. Objectives: The objectives of this meta-analysis were to compare male youth soccer players’ adaptability to small-sided games vs. conventional endurance training and to establish exercise prescription guidelines for this population. Data Sources: The data sources utilised were Google Scholar, PubMed and Microsoft Academic. Study Eligibility Criteria: Studies were eligible for inclusion if interventions were carried out in male soccer players (aged < 18 years) and compared the effects of small-sided games and conventional endurance training on aerobic endurance performance. We defined small-sided games as “modified [soccer] games played on reduced pitch areas, often using adapted rules and involving a smaller number of players than traditional games”. We defined conventional endurance training as continuous running or extensive interval training consisting of work durations > 3 min. Study Appraisal and Synthesis Methods: The inverse-variance random-effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes were represented by the standardised mean difference and presented alongside 95% confidence intervals. Results: Seven studies were included in this meta-analysis. Both modes of training were effective in increasing endurance performance. Within-mode effect sizes were both of moderate magnitude [small-sided games: 0.82 (95% confidence interval 0.05, 1.60), Z = 2.07 (p = 0.04); conventional endurance training: 0.89 (95% confidence interval 0.06, 1.72), Z = 2.10 (p = 0.04)]. There were only trivial differences [0.04 (95% confidence interval − 0.36, 0.43), Z = 0.18 (p = 0.86)] between the effects on aerobic endurance performance of small-sided games and conventional endurance training. Subgroup analyses showed mostly trivial differences between the training methods across key programming variables such as set duration (≥ or < 4 min) and recovery period between sets (≥ or < 3 min). Programmes that were longer than 8 weeks favoured small-sided games [effect size = 0.45 (95% confidence interval − 0.12, 1.02), Z = 1.54 (p = 0.12)], with the opposite being true for conventional endurance training [effect size = − 0.33 (95% confidence interval − 0.79, 0.14), Z = 1.39 (p = 0.16)]. Programmes with more than 4 sets per session favoured small-sided games [effect size = 0.53 (95% confidence interval − 0.52, 1.58), Z = 0.98 (p = 0.33)] with only a trivial difference between those with 4, or fewer, sets [effect size = − 0.13 (95% confidence interval − 0.52, 0.26), Z = 0.65 (p = 0.52)]. Conclusions: Small-sided games are as effective as conventional endurance training for increasing aerobic endurance performance in male youth soccer players. This is important for practitioners as it means that small-sided games can allow both endurance and skills training to be carried out simultaneously, thus providing a more efficient training stimulus. Small-sided games offer the same benefits as conventional endurance training with two sessions per week, with ≥ 4 sets of 4 min of activity, interspersed with recovery periods of 3 min, recommended in this population

Non-local acute stretching effects on strength performance in healthy young adults

Background Static stretching (SS) can impair performance and increase range of motion of a nonexercised or non-stretched muscle respectively. An underdeveloped research area is the effect of unilateral stretching on non-local force output. Objective The objective of this review was to describe the effects of unilateral SS on contralateral, non-stretched, muscle force and identify gaps in the literature. Methods A systematic literature search following Preferred Reporting Items for Systematic Review and Meta-Analyses Protocols guidelines was performed according to prescribed inclusion and exclusion criteria. Weighted means and ranges highlighted the non-local force output response to unilateral stretching. The Physiotherapy Evidence Database scale was used to assess study risk of bias and methodological quality. Results Unilateral stretching protocols from six studies involved 6.3±2 repetitions of 36.3±7.4 seconds with 19.3±5.7 seconds recovery between stretches. The mean stretchinduced force deficits exhibited small magnitude effect sizes for both the stretched (-6.7±7.1%, d=-0.35: 0.01 to -1.8) and contralateral, non-stretched, muscles (-4.0±4.9%, d=-0.22: 0.08 to -1.1). Control measures exhibited trivial deficits. Conclusion The limited literature examining non-local effects of prolonged SS revealed that both the stretched and contralateral, non-stretched, limbs of young adults demonstrate small magnitude force deficits. However, the frequency of studies with these effects were similar with three measures demonstrating deficits, and four measures showing trivial changes. These results highlight the possible global (non-local) effects of prolonged SS. Further research should investigate effects of lower intensity stretching, upper versus lower body stretching, different age groups, incorporate full warm-ups, and identify predominant mechanisms among others