When should a child begin to train, and why the old fear was wrong

Most parents assume weights are off-limits until the teenage years. Two decades of paediatric consensus say otherwise, and the reason has more to do with the nervous system than with muscle.

Ask a room of parents whether their eight-year-old should lift weights and you will watch faces change. Someone will mention growth plates. Someone else will have heard that lifting stunts your height. A third will say, reasonably enough, that children get plenty of exercise running about, so why complicate it.

The instinct behind all three responses is protective and entirely understandable. It is also, according to the last twenty years of paediatric sports medicine, mistaken.

Supervised strength work is safe for children. It does not stunt growth. It can begin far earlier than most parents imagine, and the American Academy of Paediatrics puts the starting point at around five years old, in the form of one-legged hops and frog jumps rather than barbells. The 2014 International Consensus on youth resistance training, endorsed by professional bodies across sports medicine, exercise science and paediatrics, found no evidence that appropriately supervised training damages the growing skeleton. What changes in a trained child is mostly not the size of the muscle at all. It is how well the brain talks to it.