Table 2

Study coding

Sex

  • Male youth athletes

  • Female youth athletes

Chronological age

  • Children (boys: ≤13 years; girls: ≤11 years)

  • Adolescence (boys:14–18 years; girls: 12–18 years)18

Biological age

  • Prepubertal (tanner stage: I–II)

  • Postpubertal/pubertal (tanner stage: III–V)

Sport

  • Team sports (eg, soccer)

  • Martial arts (eg, judo)

  • Strength-dominated sport (eg, weight-lifting)

  • Technical/acrobatic sports (eg, gymnastics)

Type of resistance training

  • Machine based

  • Free weights

  • Combined machine based and free weights

  • Functional training

  • Complex training

  • Plyometric training

Outcome categories

  • Muscle strength (preferred one repetition maximum)

  • Vertical jump performance (preferred countermovement jump)

  • Linear sprint performance (preferred 20 m sprint)

  • Agility (preferred t-agility-test)

  • Sport-specific performance (preferred throwing, hitting and/or kicking velocities)