The Effects of 12-week Home-Based Bench Stepping Exercise on Aerobic Capacity and Cardiac Autonomic Nervous Activities in Older Adults

Aim: To examine the effect of a 12-week home-based exercise intervention on the cardiac autonomic nervous system (ANS) in older adults. Method: Twenty-two older subjects (male; n=12, female; n=10, >65 yr.) were divided into either an exercise intervention group (EX) or a control group (CO). The EX group participated in a 12-week intervention mainly consisting of home-based bench stepping exercise at the intensity of lactate threshold (LT). The EX subjects were instructed to perform >20 min/day of the bench stepping exercise at their home. Before and after the 12 weeks intervention, the ANS was assessed by the spectral analysis of R-R interval variability. Based on the power frequency algorism, we evaluated the high-frequency power (HF), low-frequency power (LF), sympathetic nervous activity (SNS), and TOTAL power (LF+HF). Additionally, the aerobic capacity was evaluated as the LT using a simple bench stepping test. Results: In the EX patients, the LT was significantly increased after the intervention compared with the baseline levels (p<0.05), but was unchanged in the CO patients. There were no significant changes in ANS-related parameters in either group. The LT significantly correlated with the change in the HF and SNS (p<0.05). Furthermore, the weekly training time was significantly associated with the HF (p<0.05). Conclusion: The present investigation could not find any apparent improvement in the ANS in older adults after the home-based bench stepping exercise at the LT for <140 min/week, due to the small improvements in the aerobic capacity caused by the short training duration.