My 17 year old son, who has type 1, has bought some weights, hoping that he will build up some muscle on his arms. He’s a slim person and only wants them for his arms, as I mentioned. I have been told that it’s best if he stays away from weights. Is this true? Is he doing some kind of damage to his body? If so, I must tell him to stop. The weights (dumbbells) are a total of 10 kg (22 pounds, 2 ounces). The box contains two cast irons of 2 kg, four cast irons of 1 kg and the bar is 2 kg. For each arm, he’s using only 4 kg and doing around 40 arm lifts. I would appreciate any help/advise.

In order to build muscle, resistance needs to be applied to it. This can be in the form of free weights (i.e., dumbbells), weight machines at the gym, or using the resistance of one’s bodyweight (i.e., push-ups). Depending on the goal, different sets, repetitions, and amount of weight being lifted can determine whether muscle size increases or muscle endurance. Typically, three sets of ten repetitions is a good starting point to build muscle or what is referred to as the hypertrophy phase. If muscular endurance is a goal, moving the repetitions to 15, but also decreasing the amount of weight, will help accomplish this goal.

It is okay for teenagers to lift weights as long as it is done safely. Lifting heavy free weights without supervision is not considered safe. Having a spotter is important especially if free weights are used during overhead lifting. Keeping good form with light weights is preferred to heavier weights.

When lifting, it is important to work opposing muscles or muscle groups. For instance, if a goal is to increase the size of the biceps, doing bicep curls will work. But, it is just as important to work the triceps by doing tricep extensions. A good rule is when an exercise is done pulling a weight, make sure a pushing exercise is also performed.

Young weight lifters tend to stick with two or three lifts. A bench press, bicep curls, and maybe a lat pulldown. To cut down on injuries and build the muscles symmetrically, it would be prudent to do a row, tricep extension, and military press which work the opposing muscles of the three lifts mentioned above.

RP