How much running training is too much for kids?
How far children should run is a difficult question to answer. However, the International Association of Athletics Federations offers guidelines on the maximum distance children should run in any one session. It also advises that training frequency for those up to 14 years old should not exceed three sessions per week; teens aged 15-18 can train up to five times per week.
Under 9: Maximum distance: 3K
9-11: Maximum distance: 5K
12-14: Maximum distance: 10K
15-16: Maximum distance: Half-marathon(21.1K)
Please note that every child is different, and it depends on age, physical development, fitness levels, type of running and personal preference.
Finally, children must follow the same injury-prevention strategies that adults do. For example, running on softer surfaces where possible, warming up, not running if something hurts and stretching afterwards will help them to stay healthy and injury-free.