The research behind Train Wizard

How much weight, at each age

• 12 and under: bodyweight, plus light dumbbells. 13 and 14: dumbbells and kettlebells, weights they could lift 8 to 15 times.
• Barbell lifts start at 15, once technique is good. 16 to 18 never go heavier than a weight they could lift about 6 times.
• No barbell squats, deadlifts or Olympic lifts before 15, because Train Wizard has no coach in the room.

Sources

• Australian Strength and Conditioning Association, resistance training for children and youth (2007, updated 2017)
• NSCA youth resistance training position statement (Faigenbaum et al. 2009)
• International consensus on youth resistance training (Lloyd et al. 2014)

Jumping and sprinting

• Jump training every week, kept to safe amounts, and jump days spaced at least 3 days apart.
• Sprint work matched to age, with no more than 16 sprints in a session.

Sources

• Plyometric training by maturity, meta-analysis (Ramirez-Campillo et al. 2023)
• Plyometric training in children, meta-analysis (Johnson et al. 2011)
• Sprint training in boys aged 10 to 18, meta-analysis (Moran et al. 2017)
• Sprint training in youth, meta-analysis (Rumpf et al. 2012)

Fitness running, and exercises you'll recognise

• From 13, an optional fitness session of repeat shuttles, like the repeated-sprint training tested with 14 year olds. The QRL's junior framework sets fitness work for 13 to 15 year olds.
• Exercises young players see in youth rugby programs online, like the Copenhagen plank, Bulgarian split squats and face pulls, but only where they fit the age rules above. The popular name is shown with each one.

Sources

• Repeated-sprint training in 14 year olds (Buchheit et al. 2010)
• Queensland Rugby League Physical Performance Framework (2025)
• Copenhagen adduction exercise in under-19 footballers (Ishøi et al. 2016)

Warm-ups that cut injuries

• 13 and over warm up with World Rugby's Activate programme, which cut match injuries in school rugby.
• 12 and under do a dynamic warm-up made for their age, built on the same ideas as researched youth warm-ups.

Sources

• World Rugby Activate
• Activate in English school rugby (Barden et al. 2022)
• "11+ Kids" warm-up trial in under 13s (Rössler et al. 2018)
• Neuromuscular warm-ups in youth, meta-analysis (Steib et al. 2017)

Rest, and not too much sport

• No session on game day, nothing hard on the legs the day before, and at least 2 rest days a week.
• Total sport hours a week no more than their age, counting club training and games.
• Time off their main sport each year, staying active with other sports.

Sources

• American Academy of Pediatrics, sports specialisation and intensive training (Brenner 2016)
• Sports specialisation and overuse injury in young athletes (Jayanthi et al. 2015)
• NATA youth sports specialisation recommendations (2019)
• IOC consensus on youth athletic development (Bergeron et al. 2015)

Training for their position

• Extra work for their position, like more sprinting for outside backs and more strength and carries for forwards.
• Built on research into what each position does in youth and senior rugby. Heavy gear still follows the age rules.

Sources

• Physical qualities of elite youth rugby league players, review (Till et al. 2017)
• Strength and conditioning in adolescent rugby players (Weakley et al. 2019)

Progress tests

• 10 m and 20 m sprints, vertical jump and 5-0-5 agility: the tests used with youth rugby league players. At the start, then every 12 weeks.
• Players only ever compare with themselves, and the app shows a trend rather than judging one test.

Sources

• Fitness testing and career progression in junior rugby league (Till et al. 2016)
• Reliability of tests in academy rugby league (Dobbin et al. 2017)

Healthy habits, not addictive ones

• Weekly goals as a range, streaks that count weeks, and skip passes, so one bad day doesn't undo everything.
• No guilt messages, no late-night alerts, no endless feeds and no public rankings of players.

Sources

• Range goals (Scott and Nowlis 2013)
• Why students drop out of sport in late adolescence, review
• 5Rights Foundation, Disrupted Childhood

Where research doesn't set the rule

We'd rather tell you than overclaim. These are coaching choices:

• The exact age for advanced moves, like depth jumps from 16 and weighted chin-ups after good bodyweight reps.
• Some technique drills, like A-skips. They're used alongside proven sprint training.
• Cool-downs and the easy stretch day help players settle and keep moving, but research doesn't show they prevent injury or soreness.