The purpose of this study was to clarify the relationship of the accumulated number of heart beats (HB) for 24 hours with the maximal oxygen intake and the maximal heart rate. Subjects for this study were the training group of 25 males, which consisted of 10 middle and long distance runners and 15 soccer players who had been in long-term endurance training of average 4.8 years, and the control group of 27 males.
　In the training group, the maximal oxygen intake was 60.41 ml/kg・min (3.63 l/min), significantly greater than that of the control group i.e. 47.02 ml/kg・min (2.88l/min) (p<0.001), and HB for 24 hours was 85,109 beats, significantly lesser than that of the control group i.e. 97,410 beats (p<0.001).
　The subject with the greater aerobic work capacity had the lesser HB for 24 hours due to the training bradycardia, and its decrease was determined by the decrease of heart rate during both waking and sleeping.
　It was shown that the subject with the higher daily heart rate also has the higher maximal heart rate at all out exercise.

DESCENTE SPORTS SCIENCE Vol.6/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE