Although delayed heart rate recovery (HRR) and impaired autonomic nerve system (ANS) modulation after acute exercise are related with cause of cardiovascular disease (CVD) and mortality, studies evaluating ANS changes with local exercise are still unsatisfied. Thus, this study aimed at investigating the modulation of ANS-related parameters, followed by upper or lower body exercise. Eleven male without cardiovascular and orthopedic diseases measured basic body composition, resting blood pressure (BP), and heart rate variability (HRV). This study based on randomized cross-over design; AE composed with arm-ergometer, and LE involved with leg cycling. Participants had at least one week wash-out between each exercise, also there was no cool-down after exercise. All sessions were performed with intensity of 50 % target heart rate for 30 min. With measurement of Rating of perceived exertion (RPE) during every 10 min, HRV was measured Kubios HRV software using R-R intervals collected with Polar RS800CX in post-exercise recovery (for 30 min). As a result, heart rate (HR) and RPE were same (p > 0.05) through the experiment. As results of this study, SDNN and rMSSD in time domain on LE were higher than on AE during post-exercise recovery. When LE compared with AE used by Poincare plot, both parasympathetic reactivation (SD1) and autonomic nerve regulation (SD 2) on LE were higher than AE. Immediately after submaximal exercise, the high-frequency component on LE was significantly greater compared to AE. Also, the LF/HF ratio and LF nu reflecting sympathetic activity were higher on AE than LE. In contrast, the HF/TP ratio and HF nu reflecting vagal tone were greater on LE than AE. In conclusion, this study suggested regional lower body exercise recovers more sufficient than regional upper body exercise after submaximal aerobic exercise at same HR. Local exercise like leg cycling needs a careful approach to apply for accurate exercise prescription and effective training.
This study was designed to investigate the effects of increment of physical activity for 12 weeks through aerobic exercise training or change from own vehicle to public transportation for commuting on physical fitness, insulin resistance, inflammatory markers, and liver function in middle-aged men. Forty-four subjects, aged 30-50 yrs, were randomly assigned to either one of three groups, i.e., aerobic exercise training group (TR: n=14), change to public transportation group (PT: n=15), or control group (CON: n=15). Subjects in TR performed aerobic exercise for 30 min per sessions, three sessions per week, subjects in PT changed from their own vehicle to public transportation for commuting, and subjects in CON maintained their life patterns during the same intervention period. Physical fitness, insulin resistance, inflammatory markers, and liver function were measured at pre- and post-test, and the data were analyzed by repeated two-way ANOVA. Main results of the present study were as follows: 1) All variables related to physical fitness improved significantly in TR. Right grip strength, standing long jump, side step test, and sit-and-reach improved significantly in PT. 2) Although there were no significant changes in all variables related to insulin resistance, the variables tended to be improved in TR and PT. 3) TNF-α decreased significantly in TR and PT. IL-6 and CRP tended to be improved in TR and PT; however, the changes did not reach statistical significant level. 4) ALT decreased significantly in PT. AST and γ-GT tended to be improved in TR and PT; however, the changes did not reach statistical significant level. It was concluded that the 12 weeks of change to public transportation as well as aerobic exercise training would be beneficial for physical fitness and inflammatory markers. These interventions also would be possible to improve insulin resistance and liver function. The increment of physical activity through change from own vehicle to public transportation was found to be equally beneficial for health promotion compared to aerobic exercise.
