With such scrutiny on childhood obesity, you may be wondering if your child should be lifting weights in order to stay fit. Some kids who are involved in athletics and team sports might feel pressured to start lifting weights in order to improve performance. But it's important to make the distinction between strength-building exercises, which help kids build strength and may prevent injuries, and weightlifting or bodybuilding, which are normally done to build bulk. Children who haven't gone through puberty won't build big muscles, like bodybuilders would, no matter how hard they train. And children who haven't gone through puberty can hurt their bodies training this way. Heavy weights can put too much strain on bones that haven't completely hardened and still contain sections of cartilage, called growth plates. Resistance training with light bands and body-weight resistance exercises are best for kids. Light dumbbells are good, too.