A 15-year-old boy is in the office for a preparticipation sports physical examination before he begins playing with the varsity football team at his school. Although he is a skilled receiver, he will be one of the smallest players on the field and is concerned about the potential for injury. He asks how to bulk up. Appropriate advice to increase muscle mass includes which of the following?
a) High-protein diet and strength training
b) Low-calorie diet and aerobic exercise
c) Avoiding carbohydrates and focusing on fats
d) Excessive use of anabolic steroids