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

• Main Authors: Damir Zubac, Nandu Goswami, Vladimir Ivančev, Zoran Valić, Boštjan Šimunič
• Format: Article
• Language: English
• Published: Nature Publishing Group 2021-06-01
• Series: Scientific Reports
• Online Access: https://doi.org/10.1038/s41598-021-91565-w

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.