Selection criteria
| Category | Inclusion criteria | Exclusion criteria |
|---|---|---|
| Population | Healthy young athletes (mean age of 6–18 years) | Children/adolescents without an athletic background (ie, organised athletic training) |
| Intervention | Resistance 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 |
| Comparator | Active 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 enhancements16 | Only a passive control (ie, no regular training) and/or an alternative training group as control only (eg, stable vs unstable RT) |
| Outcome | At least one measure of muscle strength, vertical jump performance, linear sprint performance, agility and/or sport-specific performance | Effects 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 design | Controlled study | No controlled study |