Independent influence of age on heart rate recovery after flywheel exercise in trained men and women

Abstract The present study examined whether differences in the heart rate recovery following flywheel exercise cessation were associated with differences in maximal oxygen uptake ( $${\dot{\text{V}}}$$ V ˙ O2 max.), age and sex in trained adults. Eleven men (age range 22–49 years, $${\dot{\text{V}}}$$ V ˙ O2 max. = 43.6 ± 7.6 mL kg min−1) and ten women (age range 20—53 years, $${\dot{\text{V}}}$$ V ˙ O2 max. = 38.0 ± 5.7 mL kg min−1) were randomly assigned to complete a squat-exercise on the flywheel ergometer set at three different moments of inertia, while their cardiovascular responses were continuously monitored. During the flywheel exercise the mean arterial pressure rose by ~ 35 to 40% (p = .001), and the increment was more robust in men than women. The cardiac index was two-fold greater across both sexes compared to the baseline (p = .001), while the rise in heart rate (~ 144 bpm) was more pronounced in women to compensate for their load-dependent stroke index decline (p = .001). The load-independent time-course changes in heart rate recovery markers were comparable between the sexes. When these indicators were pooled, a stepwise regression revealed age as the only relevant predictor of both fast and slow components of the heart rate recovery (~ 30% of the shared variance explained, p = .014). The present data suggest that the heart rate recovery declines with age, irrespective of sex, or well-preserved cardiorespiratory fitness in moderately-trained adults