Children & Adolescents (Youth Training)

WHO 2020 (ages 5–17) and U.S. Physical Activity Guidelines, 2nd ed. 2018 (ages 6–17):

• ≥60 minutes per day of moderate-to-vigorous physical activity (MVPA), mostly aerobic. WHO frames it as an average of 60 min/day across the week; PAGA says 60 minutes or more daily.
• Vigorous-intensity aerobic activity on ≥3 days/week.
• Muscle-strengthening and bone-strengthening activities on ≥3 days/week (these can be part of the 60 minutes; bone-strengthening = impact activities like running, jumping, hopping).
• Limit sedentary time, especially recreational screen time.
• Preschoolers: PAGA 2018 says children aged 3–5 should be physically active throughout the day (it suggests about 3 hours/day of any intensity as a reasonable target). WHO's separate 2019 under-5 guideline asks children aged 3–4 for ≥180 min/day of varied activity at any intensity, including ≥60 min of MVPA, plus no more than 1 hour of sedentary screen time.

Type: emphasize fun, varied, skill-based, play-driven activity; sport, active games, and structured movement skills. Bone-strengthening impact activities matter for peak bone-mass accrual.

Youth resistance training: The NSCA (2009 position statement), the American Academy of Pediatrics (2020 clinical report) and the 2014 International Consensus agree that well-designed, supervised resistance training is safe and effective for children/adolescents, improving strength, motor skill, bone health, body composition, and reducing sport-injury risk. See Youth Resistance Training — Myths vs. Evidence.

• Qualified supervision and instruction; technique before load.
• Start with bodyweight/light loads, low volume; the NSCA 2009 statement suggests 1–3 sets of 6–15 reps on a variety of upper- and lower-body exercises, 2–3 nonconsecutive days/week, after a 5–10 min dynamic warm-up.
• Progress by competence and training age (long-term athletic development, LTAD), not just chronological age — see Principle of Individuality (Individual Differences).

• Children are not miniature adults: they have larger surface-area-to-mass ratio and less efficient thermoregulation/sweating → greater heat-stress risk; ensure hydration, heat acclimatization, and rest.
• Maximal (1RM) testing: the NSCA 2009 statement says healthy children and adolescents can be 1RM-tested safely only after a habituation period to learn technique and with close supervision by qualified professionals; unsupervised or improper maximal testing should never be done. Heavy near-maximal training is not the starting point — technique and progression come first.
• Emphasize landing mechanics for jumping/plyometrics (Youth Plyometric & Power Considerations).

• Uncontrolled conditions (e.g., uncontrolled hypertension, seizure disorders, certain congenital heart conditions) warrant medical clearance and individualized guidance.
• Any chest pain, fainting, or exertional symptoms in a young person should prompt medical evaluation before continuing.

• Ages 5/6–17: ≥60 min/day MVPA; vigorous ≥3 d/wk; muscle- AND bone-strengthening ≥3 d/wk (WHO 2020; PAGA 2018).
• Preschool: active throughout the day (PAGA, 3–5 yr); WHO 2019: ≥180 min/day incl. ≥60 min MVPA (3–4 yr).
• Supervised resistance training is safe/effective; technique before load; 1–3 sets × 6–15 reps, 2–3 nonconsecutive d/wk (NSCA 2009).
• Progress by training age/maturity (LTAD), individualized.
• Higher heat-stress risk than adults; prioritize hydration and rest.