How do you get your son to be muscular?

Answer 1

The same answer applies for anyone wishing to be muscular: exercise. Muscles will only become larger if they are used. Of course, the best way is to go to the gym, but any sport will do. In terms of speediness, you'd be looking at the gym, and to increase muscle size, you'd be needing high mass (mass of 'weights' used - although 'weight' is inappropriate as the 'weights' are measured in kilograms, not Newtons), low reps. Therefore, it would be wise to tell him to do, say, five reps of the highest he can do, then rest for a minute, then do another five, and rest. Just doing loads of reps does not build muscle mass so much, just endurance and power (actual ability - muscle mass is not a good indicator of strength).

Alternatively, if you're son is a frail nerd who refuses to leave the house, use home weights (not those used for balance scales, though). There is a range of possibilities. You can use dumbbells, which you grip with one hand, or kettle bells. which are increasing in popularity due to the range of what can be done with them. Doing it at home, you will not have the amazing equipment of the gym, but you will have loads of time, and you can work any area of the body using just simple equipment, applied through the right exercise.