Endurance exercise training has a minimal effect on resting heart rate: The HERITAGE study

This study determined the effects of a 20-wk endurance training program (The HERITAGE Family Study) on resting heart rate (HR-(rest)). HR(rest) was obtained on a sample of 26 men and 21 women during sleep; during resting metabolic rate and resting blood pressure measurement periods in the early morning following a 12-h fast and 24 h post-exercise; and at rest prior to a maximal bout of exercise. Following training, the subjects exhibited a 16.0 ± 9.4% (mean ± SD) increase in V̇O(2max) (P < 0.05), but the HR(rest) for each of the resting conditions was decreased by only 1.9 to 3,4 bpm (P < 0.05), or an average across the three conditions of 2.7 bpm. In a larger sample of 253 HERITAGE subjects, HR(rest) obtained only at the time of the resting blood pressure measurement decreased by only 2.6 bpm, while V̇O(2max) increased 17.7 ± 10.0%. It is concluded that there is a significant, but small, decrease in resting heart rate as a result of 20 wk of moderate- to high-intensity endurance training; which suggests a minimal alteration in either, or both, intrinsic heart rate and autonomic control of HR(rest).