Exercise training and heart rate variability in older people

Purpose: Heart rate variability (HRV)? a characteristic that is potentially increased by physical activity, has been associated with incidence of card iac events and total mortality. Since the incidence of cardiac events among older people is high and their physical activity levels and HRV are genera lly low, it is important to investigate whether regular physical activity c an modify HRV in this age group. The purpose of the study was to investigat e the effect of regular physical activity on HRV in older men and women. Me thods: Ln a randomized controlled trial, the effect of sin months' training on HRV was investigated in a group of 51 older men and women (67.0 +/- 5.1 yr). The training group gathered three times per week for 35 min supervise d training. Results: At the end of the intervention period. HRV was higher primarily during the day. During daytime, the SD of all normal intervals (6%) as well as the low frequency component (+ 15%) and the very low frequen cy component (+ 10%) of HRV were significantly increased (P < 0.05) as comp ared with the control group. Effects of training were most pronounced in su bjects inactive in sports at baseline. Conclusion: This study demonstrates that regular physical activity increases HRV specifically in the very low a nd low frequency components) in older subjects. Hence, in older subjects, p hysical training may be an effective means to modify positively a factor th at is associated with increased incidence of cardiac events.