Warming up before an exercise can help stretch your muscles to avoid injury. It can also help prepare your body for the exercises you do in your workout. Cooling down after an exercise can help avoid soreness the next day. It also allows your heartrate and blood pressure to return to what it was before the workout.
That just because he's eating more protein doesn't mean that he'll get more muscles, extra protein could cause you problems too. So only take the necessary, and do exercise
