A systematic review on the effects of resistance and plyometric training on physical fitness in youth- What do comparative studies tell us?

Abstract

IntroductionTo date, several meta-analyses clearly demonstrated that resistance and plyometric training are effective to improve physical fitness in children and adolescents. However, a methodological limitation of meta-analyses is that they synthesize results from different studies and hence ignore important differences across studies (i.e., mixing apples and oranges). Therefore, we aimed at examining comparative intervention studies that assessed the effects of age, sex, maturation, and resistance or plyometric training descriptors (e.g., training intensity, volume etc.) on measures of physical fitness while holding other variables constant.MethodsTo identify relevant studies, we systematically searched multiple electronic databases (e.g., PubMed) from inception to March 2018. We included resistance and plyometric training studies in healthy young athletes and non-athletes aged 6 to 18 years that investigated the effects of moderator variables (e.g., age, maturity, sex, etc.) on components of physical fitness (i.e., muscle strength and power).ResultsOur systematic literature search revealed a total of 75 eligible resistance and plyometric training studies, including 5,138 participants. Mean duration of resistance and plyometric training programs amounted to 8.9 ± 3.6 weeks and 7.1±1.4 weeks, respectively. Our findings showed that maturation affects plyometric and resistance training outcomes differently, with the former eliciting greater adaptations pre-peak height velocity (PHV) and the latter around- and post-PHV. Sex has no major impact on resistance training related outcomes (e.g., maximal strength, 10 repetition maximum). In terms of plyometric training, around-PHV boys appear to respond with larger performance improvements (e.g., jump height, jump distance) compared with girls. Different types of resistance training (e.g., body weight, free weights) are effective in improving measures of muscle strength (e.g., maximum voluntary contraction) in untrained children and adolescents. Effects of plyometric training in untrained youth primarily follow the principle of training specificity. Despite the fact that only 6 out of 75 comparative studies investigated resistance or plyometric training in trained individuals, positive effects were reported in all 6 studies (e.g., maximum strength and vertical jump height, respectively).ConclusionsThe present review article identified research gaps (e.g., training descriptors, modern alternative training modalities) that should be addressed in future comparative studies.

Does an effective shoulder injury prevention program affect risk factors in handball? A randomized controlled study

“…Since we randomized the players within each team, this did not affect the gender distribution between the intervention and control group. According to Peitz et al, 38 sex does not affect resistance training‐related outcome when comparing males and females of same age. However, our sample size is too small to compare male to female players.…”

Integrated Strength and Fundamental Movement Skill Training in Children: A Pilot Study

“…Strength and conditioning-based exercises are safe and effective modalities to enhance physical fitness [ 36 ] and reduce injury risk [ 37 ] in youth. Improved strength at an earlier age may also provide the skills and confidence required to remain physically active as an adult [ 38 ].…”

Effects of Supplementary Strength–Power Training on Neuromuscular Performance in Young Female Athletes

“…Recently, it was suggested that a combination of two or more types of training may be more efficient to improve fitness and sport performance of youth athletes [32][33][34]. For example, a combined resistance and plyometric training program, performed for 6 weeks enhanced maximal strength, countermovement jump height, and sprint speed in three groups of youth basketball players (13)(14)(15)(15)(16)(17), and >17 years), although the training program used in that study was less effective as the age of the basketball players increased [32].…”