How much running is enough for a kid?

This is one of the more-googled parent questions, especially in households with one runner-parent or one football-mad child. The answer has two halves: how much aerobic activity is good, and when does deliberate "training" become a thing?

How much aerobic activity is enough

The WHO 60-minute target (plain-language version) is mostly aerobic and includes children's natural play. Below 60 minutes per day, you measurably miss out on cardiovascular and cognitive benefit. Above 60 minutes per day, the benefit continues to grow with diminishing returns out to roughly 90-120 minutes per day, and then plateaus.

That plateau is important. There is no good evidence in the paediatric exercise-science literature for a substantial benefit of adding aerobic training above ~2 hours per day for children under 12. Above that, you start seeing the costs (overuse injury, sleep cost, social cost) without the benefit.

When deliberate training becomes a thing

Sport-science consensus, summarised by the long-running Long-Term Athlete Development (LTAD) framework (Balyi & Way, multiple revisions, most recent 2013), is that:

• Under 6: play, not training. Variety, not specialisation.
• 6-9: "fundamental movement skills" — running, jumping, throwing, catching, balancing. Still play-based. Multiple sports.
• 9-12: introduction of sport-specific skill, but with multiple sports. Specialisation in one sport before 12 is associated with higher injury rates and earlier dropout.
• 12-15: the window where serious training in one or two sports starts to make sense, and where physiological capacity for adaptation is highest.
• 15+: competitive specialisation if the child wants it.

This sequence is widely accepted in elite sport development. It is also widely ignored by enthusiastic parents and coaches who specialise children too early.

What to do at home

For a child under 12 who loves sport:

• Let them do as much general aerobic activity as they want, as long as it doesn't eat sleep or schoolwork.
• Encourage variety. A child who plays football and swims and rides a bike and does an occasional martial art will be a better athlete at 16 than a child who has done nothing but football since 7.
• Treat any "training plan" with serious scepticism before 12. There are exceptions (gymnastics, swimming, tennis at very high levels) but these are exceptions and they have known costs.
• Watch sleep. Children who train hard often sleep less; children who sleep less (why this matters) recover less and get hurt more.

When to worry

Three signals:

1. Persistent fatigue. A child who is genuinely over-trained looks tired in the morning and at school, not just after practice.
2. Recurring small injuries. Shin splints, knee aches, repeated ankle sprains under 12 are the body asking for variety, not for stronger ankles.
3. Loss of enthusiasm. A child who used to love football and now reluctantly goes is worth a conversation. Sometimes it's social. Sometimes it's overload.

For everything else, the WHO 60-minute target is a floor, not a ceiling. A kid who runs around outside for 90 minutes a day is doing exactly what their body is built for. The unstructured outdoor afternoon delivers most of this without anyone tracking it.