The slow heart rate of athletes is mainly due to long-term exercise, so that their cardiac muscle contraction capacity is stronger than ordinary people and the autonomic function is more stable.
Long-term and prolonged exercise puts the athlete’s heart in a state of high load, and in order to supply the body with what it needs, myoglobin and contractile proteins increase, a large number of new capillaries appear in the myocardium, and myocardial fibers become thicker and contractile force becomes stronger.
In addition, the above mechanisms also lead to an increase in the volume of the athlete’s heart, and thus, in a quiet state, the athlete ejects more blood per heart beat than a normal person, and accordingly, the number of heartbeats per minute decreases.
Athletes are trained to have increased vagal tone and decreased relative sympathetic tone, which directly contributes to the slowing of the heartbeat.