Should I Use Heavy Weights?
A. Don’t use heavy weights yet! Teens should start out with lighter weights, proper form, and more repetitions. A good rule of thumb is to start with a weight you can easily lift 10 times, with the last two repetitions being increasingly difficult. For some teens, this might be 1 pound to 2 pounds. If you are strong and fit, you might start at 15 pounds to 20 pounds. When lifting, move the weights in a smooth, steady motion. Avoid jerky movements and sudden drops.
As your muscles gain strength, and if there is no pain, slowly increase the weight in 1- to 2.5 -pound increments if using free weights, in 5-pound increments if using gym machines. Stay away from very heavy weights until you are fully through puberty and growth, as it could damage tendons and bones. Talk to your doctor or PE coach about the type of weights that are best for you.