Jim Dreeben, 83, took up CrossFit in his 80s and got hooked. He does 100 push-ups and also planks six days a week, and his doctor told him to keep going. Dreeben's active lifestyle includes kayaking, ...

I'm not the biggest fan of upper-body workouts, i.e. push-ups, but I do know that that I've got to do them if I want to have a strong upper body. I don't have the desire to do 50 push-ups first thing ...