Weightlifting for young people – with correct supervision and technique – has no bearing on how they grow. When a ten-year-old does push-ups, or jumps up and down, they are essentially lifting around 30-50 kilograms (66-110 pounds).
However, it’s important to understand that growth plates in young people are not fully developed. Growth plates are soft areas of cartilage around the ends of bones, and they regulate growth in children and young teens.
They do this by being the last part of the bone to harden, allowing the bone to develop to the desired length. Growth plates are more vulnerable to fractures in youngsters. Excessive weightlifting with poor technique could damage these plates.
Answered by Rik Sargent