Q: hi mike I'm 10 years old and I want to develop my biceps ..I'm a basketball player can I use dumbbells or would it affect my hieght.

A: At your age you should not use excessively heavy weights and should not train to failure (meaning you should stop your sets before you reach the point of total exhaustion. With those two things taken care of it's fine for you to weight train (such as with dumbbells) under adult supervision. Keep in mind that you shouldn't expect too much muscle development at your age, no matter how much you train, but you can certainly build strength and prepare for your big growth phase in a few years when you really will have great potential to build muscle mass.