RELATIONSHIP BETWEEN POST-EXERCISE HEART RATE AND HEART RATE RECOVERY ON ESTIMATED VO2MAX IN YOUNG ADULTS

PURPOSE: Post-exercise heart rate recovery (HRR) is related to aerobic fitness and relevant in exercise prescription. The purpose of this study was to investigate the relationship between post-exercise HR and short-term HRR intervals, following the completion of a validated aerobic step test in young adults. METHODS: Ten (4 female, 6 male) participants (age 24 ± 3 yr) completed the Queens College Step Test to estimate VO2max. Following completion of the test, HR was measured at the 5 (HR5), 10 (HR10), 15 (HR15), and 20 (HR20) second marks, in accordance to test protocol. Additionally, the 10 (HRR10), 15 (HRR15), and 20 (HRR20) second HR were subtracted from the initial 5 second HR value to create HRR score for each timepoint. Pearson’s product moment correlations were used to investigate the relationship between variables of interest and estimated VO2max. A p-value of ≤0.05 was used to determine the significance of any relationship, and data are presented as mean ± standard deviation. RESULTS: A significant, positive, moderate correlation was found between HRR20 (11.8 ± 6.5 bpm) and estimated VO2max (44.0 ± 7.3 ml/kg/min; p = 0.04, r = 0.67). All other variables revealed non-significant, weak-to-moderate correlations to estimated VO2max: HR5 (157 ± 21 bpm; p = 0.17, r = -0.48); HR10 (155 ± 22 bpm; p = 0.17, r = -0.48); HR15 (150 ± 23 bpm; p = 0.10, r = -0.56); HR20 (146 ± 24 bpm; p = 0.08, r = -0.59); HRR10 (3 ± 3 bpm; p = 0.59, r = 0.20); and HRR15 (7 ± 5 bpm; p = 0.15, r = 0.50). Additional significant relationships existed when separated by sex, though small sample sizes limits the importance of these comparisons. CONCLUSION: Higher HRR is correlated to higher estimated VO2max scores in this sample of young adults. However, the relationship is weaker during the first 5-15 s following cessation of exercise when compared to the 20-s timepoint, demonstrating that short-term HRR dynamics - immediately following exercise - warrants further investigation.