4.2 A resting heart rate
We can understand the role of the athlete's heart in sport a little more clearly by looking at typical heart rates for trained athletes compared with heart rates for non-athletes. A commonly used measure of heart efficiency is called the resting heart rate. This is the number of times per minute that the heart beats when a person is relaxed and resting. The heart rate for a reasonably healthy adult when they are relaxed and resting is in the range of 55–65 beats per minute. This means that this person's heart has to beat about 60 times per minute to supply the amount of blood that the body needs.
When an elite athlete is relaxed and resting, their body needs the same amount of blood as the average adult mentioned above. However, because they train to make their hearts more efficient, each single beat of their heart pumps more blood than average. As a result, their hearts don't have to beat as fast to supply the same amount of blood. Hence the resting heart rate of an elite athlete is much lower than that for an average person: for many athletes, it is about 40 beats per minute. For exceptional athletes, it can be as low as 30 times per minute. This is incredibly low – if the heart rate of a ‘normal’ person was this low, they would be rushed to hospital in an ambulance! For some elite athletes, however, natural physical ability combined with training regimes can make even these extremely low heart rates perfectly healthy.