title: Effects of moderate and vigorous physical activity on heart rate variability in a British study of civil servants.
abstract: Physical inactivity and low resting heart rate variability (HRV) are associated with increased coronary heart disease incidence. In the Whitehall II study of civil servants aged 45-68 years (London, United Kingdom, 1997-1999), the strength of the association of moderate and vigorous activity with higher HRV was examined. Five-minute recordings of heart rate and HRV measures were obtained from 3328 participants. Calculated were time domain (standard deviation of NN intervals) and high-frequency-power measures as indicators of cardiac parasympathetic activity and low-frequency power of parasympathetic-sympathetic balance. Leisure-time physical activity (metabolic equivalent-hours per week) was categorized as moderate (>or=3-<5) and vigorous (>or=5). Moderate and vigorous physical activity were associated with higher HRV and lower heart rate. For men, linear trends of higher low-frequency power with increasing quartile of vigorous activity (304.6 (low), 329.0, 342.4, 362.5 (high); p < 0.01) and lower heart rate with increasing quartile of moderate activity (69.6 (low), 69.2, 68.9, 67.8 (high); p < 0.05) were found. These associations remained significant after adjustment for smoking and high alcohol intake. For men whose body mass index was >25 kg/m(2), vigorous activity was associated with HRV levels similar to those for normal-weight men who engaged in no vigorous activity. Vigorous activity was associated with higher HRV, representing a possible mechanism by which physical activity reduces coronary heart disease risk.
authors.affiliation: Department of Epidemiology and Public Health, University College London, London, United Kingdom.
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Rennie
authors.forename: Harry
authors.initials: H
authors.lastname: Hemingway
authors.forename: Meena
authors.initials: M
authors.lastname: Kumari
authors.forename: Eric
authors.initials: E
authors.lastname: Brunner
authors.forename: Marek
authors.initials: M
authors.lastname: Malik
authors.forename: Michael
authors.initials: M
authors.lastname: Marmot
mesh_terms: D000368:Aged; D015992:Body Mass Index; D003430:Cross-Sectional Studies; D004562:Electrocardiography; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007899:Leisure Activities; D008131:London; D008297:Male; D008875:Middle Aged; D005082:Physical Exertion / Q000502:physiology*; D012146:Rest / Q000502:physiology; D012307:Risk Factors; D011795:Surveys and Questionnaires