Table 1

Selection criteria

CategoryInclusion criteriaExclusion criteria
PopulationHealthy young athletes (mean age of 6–18 years)Children/adolescents without an athletic background (ie, organised athletic training)
InterventionResistance training (RT; specific conditioning method, which involves the use of a wide range of resistive loads and a variety of training types designed to enhance proxies of health, fitness and sports performance)Fewer than 6 RT sessions
ComparatorActive control (ie, age-matched; conducting the same regular training as the intervention group) in order to avoid bias due to growth and maturation-related performance enhancements16Only a passive control (ie, no regular training) and/or an alternative training group as control only (eg, stable vs unstable RT)
OutcomeAt least one measure of muscle strength, vertical jump performance, linear sprint performance, agility and/or sport-specific performanceEffects of nutritional supplements; report no means and SDs/SE for the intervention and control groups post test in the results and did not reply to our inquiries sent by email
Study designControlled studyNo controlled study