Vigorous physical activity predicts higher heart rate variability among younger adults

BACKGROUND: Baseline heart rate variability (HRV) is linked to prospective cardiovascular health. We tested intensity and duration of weekly physical activity as predictors of heart rate variability in young adults. MAIN BODY OF THE ABSTRACT: Time and frequency domain indices of HRV were calculated based on 5-min resting electrocardiograms collected from 82 undergraduate students. Hours per week of both moderate and vigorous activity were estimated using the International Physical Activity Questionnaire. In regression analyses, hours of vigorous physical activity, but not moderate activity, significantly predicted greater time domain and frequency domain indices of heart rate variability. Adjusted for weekly frequency, greater daily duration of vigorous activity failed to predict HRV indices. CONCLUSIONS: Future studies should test direct measurements of vigorous activity patterns as predictors of autonomic function in young adulthood.