Background: Excess weight is associated with cardiac autonomic dysfunction at rest and during exercise. Exercise training has been proven to be effective for restoring cardiac autonomic function.

Objective: To evaluate the effect of arm swing exercise (ASE) training on cardiac autonomic function in response to incremental exercise in overweight young adults.

Materials and Methods: Forty sedentary young adults were classified into overweight and normal weight groups in accordance with age and sex. All subjects took part in an ASE training program for 2 months, 30 minutes/day, 3 days/week. Before and after the training, subjects’ cardiac autonomic function was evaluated via heart rate variability analysis throughout the incremental exercise as well as during recovery.

Results: Prior to ASE training, during low-intensity exercise, mean heart rate (HR) in the overweight group was higher than that in the normal weight group (p<0.05). However, during high-intensity exercise, mean HR and the longitudinal diameters of the Poincaré plot (SD2) value in the overweight group were lower than those in the normal weight group (p<0.05). These differences disappeared post ASE training period. During recovery from incremental exercise, before ASE training, mean duration of all normal to normal RR intervals (RR values) were higher (p<0.05), and the ratio between low and high frequency components was lower (p<0.05) in the overweight group compared to those in the normal weight group. Higher mean RR values in the overweight group were maintained post ASE training period (p<0.05).

Conclusion: The present study suggested that in response to high-intensity exercise, parasympathetic nerve activity is predominant in young overweight adults. ASE training for 2 months improved cardiac autonomic activity in response to incremental exercise in overweight young adults.

Keywords: Heart rate variability, Body mass index, Effort