7. Many athletes who are in good condition have heartbeat rates that are substantially slower than the 60 to 80 beats per minute (bpm) considered normal for the rest of us. Former cyclist Lance Armstrong routinely had a resting heart rate of about 32 bpm. For a non-athlete, a heartbeat rate this low might be cause for hospitalization, but the rate of blood flow in an athlete's body is not affected by it. How can an athlete's body function normally with such a low heartbeat rate? A. People who are athletes are born with slow heart rates so it is normal for them. B. Exercise strengthens the athlete's heart muscle so more blood is pumped with each beat. C. An athlete's heart rate is higher than normal while exercising so it averages out to normal. D. More capillaries appear in muscle tissue with exercise so blood flow is more efficient O * S​