HEART RATE VARIABILITY AND MOOD FOLLOWING MODERATE INTENSITY EXERCISE

Abstract

PURPOSE To determine the relationship between heart rate variability (HRV) and mood before and after moderate exercise. METHODS Participants were 56 healthy college-aged males (n = 30) and females (n = 26) aged 18–34 (M 24.16, SD 4.25). All participants performed a treadmill maximum oxygen uptake (V02max) test and were randomly assigned to the exercise (n = 28) or the control group (n = 28). On a separate day. HRV and three indicators of mood: state anxiety (SAI), tense arousal (TA) and energetic arousal (EA) were collected 1 min and 15 min after quiet supine rest. HRV was determined through ECG spectral analysis of 5-min heart rate recordings and PNS activity was inferred from indices of high frequency power in normalized units (HFnu). The participants then either sat quietly or ran on a treadmill for 20 min at 65% of their V02max. Post-exercise HRV and mood data were collected at 1, 15, 30 and 45 min post-exercise or rest. Growth curve modeling was used to assess the TA, EA, and SAI trajectories across the six time points. To test whether exercise moderates the relationship between HRV and mood, HRV × Group (exercise/control) interactions were examined. RESULTS The predicted HRV × Group interaction was significant for SAI (beta = −.07, p = .03), and EA (beta = −.12, p = .03). The HRV × Group interaction was marginal for the TA (beta = −.07, p = .06). CONCLUSION Parasympathetic drive appears to play a role in post exercise mood.