Effects of 12 Weeks of Combined Exercise on Heart Rate Variability and Dynamic Pulmonary Function in Obese and Elderly Korean Women

BACKGROUND: We investigated whether a combination of aerobic and resistance exercise administered over a period of 12 weeks enhanced heart rate variability (HRV) and dynamic pulmonary function (DPF) in obese and elderly Korean women. METHODS: The study was conducted in 2016 in the Konkuk University (Seoul, Korea). The study participants included 20 older obese women [aged 66.4±0.8years; >30 BMI and >30% in percent body fat]. The subjects were divided into a non-exercise group (n=10, control group; CON) and a combined exercise group (n=10, experimental group; EXP). Total power (TP), low frequency (LF), high frequency (HF), and LH/HF ratio were measured as frequency-domain methods. Salivary cortisol levels were analyzed by ELISA. The participants underwent dynamic pulmonary function (DPF) test. RESULTS: The EXP group showed a significantly decrease in body weight (P=0.002) and % body fat (P<0.001) following 12 weeks of combined exercise training. The CON group revealed a significant increase in LF (P=0.011), LF/HF ratio (P<0.001), salivary cortisol (P=0.015) and decrease in HF (P=0.003). However, the EXP presented a significant decrease in LF (P=0.006) and salivary cortisol (P=0.046), and a significantly increase in MVV (P<0.001). CONCLUSION: Twelve wk of combined aerobic and resistance exercise improves heart rate variability, reducing mental stress in obese older women. In addition, the exercise program was found to be effective in reducing body fat and improving lung function in obese elderly women in East Asian countries with similar body composition and cultural patterns. Therefore, further collaborative research is needed to investigate obese older women in East Asian countries.