The key development phases in youth football
In simplified terms, development between the ages of 6 and 18 is divided into five phases:
Phase 1: Early childhood (6–9 years)
Physical: Steady growth. No hormonal surge.
Cognitive: Concrete thinking. Learning through play.
What makes sense in training: Coordination, joy of playing, plenty of touches of the ball. Game formats rather than drills.
Phase 2: Later childhood (9–12 years)
Physical: Stable growth phase. Peak motor learning capacity.
Cognitive: Beginning of abstract thinking. Able to understand rules and implement instructions.
What makes sense in training: Focus on technique. "Golden age of learning". Speed, coordination, all ball-mastery techniques.
Phase 3: Puberty (12–15 years)
Physical: Growth spurts. Variable progress between individual children.
Cognitive: Football intelligence develops rapidly.
What makes sense in training: Careful load management. Tactical content. Focus on team systems.
Phase 4: Late puberty (15–17 years)
Physical: Growth slows down. Muscle building becomes possible.
Cognitive: Adult-like thinking. Self-reflection.
What makes sense in training: Initial athletic conditioning. Consolidating the playing system. Mental preparation.
Phase 5: Adolescence (17–19 years)
Physical: Adult level largely reached.
Cognitive: Fully developed.
What makes sense in training: Full training programme just like adults. Specialisation.
What youth players are specifically allowed to do at each age group
Here is an overview of what makes sense and is safe at each age level:
U7 (U6–U7)
Technique: All ball fundamentals through play
Speed: Very little, integrated into movement games
Endurance: Playful, never long continuous runs
Strength: Bodyweight is sufficient (climbing, obstacles)
Mobility: Automatically through movement games
Tactics: None
Training duration: 60–75 minutes max
U9 (U8–U9)
Technique: Initial passing, shooting, and receiving drills
Speed: Short relays, sprints under 5 seconds
Endurance: Game formats with breaks
Strength: Bodyweight. No weights or dumbbells.
Mobility: Playful
Tactics: Simple rules in small-sided games
Training duration: 75–90 minutes
U11 (U10–U11)
Technique: Main focus throughout this phase. "Golden age of learning"
Speed: Short sprints (max 6 seconds), acceleration drills
Endurance: Game formats, initial longer match-play periods
Strength: Bodyweight, obstacle courses
Mobility: Coordination stations
Tactics: First 1v1 concepts, simple game formats
Training duration: 90 minutes
U13 (U12–U13)
Technique: Continued focus
Speed: Sprint intervals (max 8 seconds)
Endurance: Longer game formats, first conditioning elements
Strength: Bodyweight (press-ups, pull-ups, squats). NO free-weight strength training.
Mobility: Introduce stretching
Tactics: Basics of playing systems, pressing concepts
Training duration: 90 minutes
U15 (U14–U15)
Technique: Consolidation and refinement
Speed: Classic interval speed work
Endurance: Match-realistic intervals
Strength: Cautious introduction of machine-based training possible (NOT before the end of growth spurts). Bodyweight remains the primary focus.
Mobility: Systematic stretching
Tactics: Focus on tactical systems
Training duration: 90 minutes
U17 (U16–U17)
Technique: Match-specific
Speed: Full speed spectrum
Endurance: Full, with high-intensity intervals
Strength: Strength training possible (supervised by a coach)
Mobility: Systematic
Tactics: Full tactical spectrum
Training duration: 90–105 minutes
U19 (U18–U19)
Technique: Professional-level approach
Speed: Full
Endurance: Full
Strength: Full, individually tailored
Mobility: Full
Tactics: Full
Training duration: 90–105 minutes
What you need to consider during growth spurts
Growth spurts (usually between 12 and 15 years of age) are critical. Bones grow faster than muscles and tendons. Consequences:
Risks during growth spurts
- Knee pain (Osgood-Schlatter disease)
- Heel pain (Sever's disease)
- Higher injury risk during high-speed work
- Temporary loss of coordination
What you need to do as a coach
- Take complaints of knee or heel pain seriously, do not make them "play through it"
- Reduce the training load whenever pain occurs
- Schedule recovery phases
- Alert parents to potential symptoms
Signs that a player is going through a growth spurt
- Sudden increase in height (often visible during the off-season)
- Deterioration in coordination ("suddenly looks clumsy")
- Complaints of knee or heel pain
- Fatigue beyond normal levels
During this phase: adjust training load individually. Avoid heavy sprint or jumping demands.
Strength training in youth football: What works, what doesn't
A frequently misunderstood topic. A clear baseline:
Up to 12 years
NO systematic strength training with equipment. Bodyweight is sufficient: press-ups, pull-ups, squats, obstacle work.
Playful physical engagement in game formats is the best foundation for strength.
12–14 years
Cautious introduction. Maximum of bodyweight plus light implements. NEVER maximum load. NEVER overload growth plates.
14–16 years
Beginning structured resistance training is possible – but under expert supervision. Light weights, high repetitions, precise technique. Never maximum load.
16+ years
Traditional strength training is possible. Under coaching supervision. Taking individual biological maturity into account.
What ALWAYS applies to strength training
- 15-minute warm-up
- Technique before weight
- Establish proper breathing technique
- Rest periods between sets
- Never train to muscle failure
Endurance training in youth football
Endurance is vital in football, but youth endurance must be approached differently to adult training.
Up to 12 years
NO long runs without the ball. Endurance develops through small-sided games. "We're running 5 laps now" is the wrong approach.
12–15 years
Initial sustained work, but kept match-realistic. Game formats with structured intervals. No continuous steady-state running drills.
15+ years
Traditional endurance methods are possible. However: match realism remains the priority.
Speed: What makes sense and when
Speed is decisive in football – but here, too, it depends on age:
Up to 10 years
Short, playful sprints. Acceleration drills. Never more than 5–6 seconds of continuous sprinting.
10–12 years
"Golden age of speed". Sprint intervals are possible. Reactive drills. Crucially: always with full recovery periods.
12–15 years
Be cautious during growth spurts. Otherwise: develop and consolidate.
15+ years
Full speed methodology.
How to manage training load individually
Not all 14-year-olds develop at the same rate. Month of birth, biological maturity, and training history all play a role. Three practical tips:
Tip 1: Take subjective feelings seriously
If a player says "it hurts", believe them. Do not say "toughen up". Growing pains are real.
Tip 2: Track training load visibly
With Coach OS, you can document training load. A player who has had three tough sessions in a week should take the fourth one lightly.
Tip 3: Monitor the course of the season
A player who has featured in 30 competitive matches in the first half of the season requires different load management to one who has played 10.
When to consult a sports doctor
In three key situations:
Situation 1: Recurrent pain
If a player experiences knee, heel, or back pain over several weeks – recommend a sports doctor.
Situation 2: Sudden drops in performance
If performance drops suddenly without an obvious reason – get a medical check-up. Iron deficiency or thyroid issues could be the underlying cause.
Situation 3: Prior to strength training (from age 14)
Before a young player begins structured strength training, a sports medical screening should be completed.
What should NOT happen in training
A checklist of what to avoid:
Prohibited regardless of age
- Playing through pain that goes beyond "just muscle soreness"
- Punishment sprints ("whoever fouls runs 5 laps")
- Pushing players beyond tolerable physiological limits without consequence
- Humiliation as a motivational tool
Prohibited for younger age groups
- From U7 to U11: long continuous runs
- From U7 to U11: heavy strength sessions
- From U7 to U11: maximal sprint efforts exceeding 6 seconds
- From U7 to U11: maximal physical strain in competitive situations
How Coach OS helps you with age-appropriate planning
Coach OS categorises drills by age suitability. If you coach a U13 team, you get suggested drills tailored specifically for U13s – not conditioning work meant for a U19 squad.
Specifically:
- Over 1,244 drills are categorised by age suitability
- AI takes your team's age into account when generating session recommendations
- Workload profiles are adapted to the age level
- Pitch sizes and drill distances are matched to the age group
You don't need to second-guess what is suitable for U13s – Coach OS suggests it directly.
Read more: U15 Football: Training and Coaching (U14/U15).
Frequently asked questions about training load in youth football
Conclusion: Age-appropriate training is essential – not a nice-to-have
Any youth coach who trains players without understanding growth phases risks injuries and developmental deficits in their squad.
You don't need to become a sports scientist. But knowing the basic rules, taking pain seriously, managing workload by age group, and avoiding premature strength training – that is all part of coaching.
Coach OS supports you with age-appropriate drill recommendations. You don't have to evaluate the suitability of every single drill yourself.
Try Coach OS for age-appropriate training 30 days free →
Coach OS is the platform for football training session planning. Featuring over 1,244 drills, categorised by age suitability. From Hamburg.