Physical training significantly increased cardiac parasympathetic activity (RMSSD) in obese children, an effect that reversed upon cessation of training (time by group interaction P=0.026).
RCT (n=79)
Randomly assigned
Does physical training improve cardiac parasympathetic activity in obese children?
Regular physical training improves cardiac parasympathetic activity in obese children, but these benefits reverse upon cessation of training.
p-value: p=0.026
OBJECTIVE: Heart rate variability provides non-invasive information about cardiac parasympathetic activity (PSA). We determined in obese children: (1) relations of baseline PSA to body composition and hemodynamics; (2) effects of physical training (PT) and cessation of PT; and (3) which factors explained individual differences in responsivity of PSA to the PT. RESEARCH METHODS AND PROCEDURES: The root mean square of successive differences (RMSSD) was the index of PSA. Obese children (n = 79) were randomly assigned to groups that participated in PT during the first or second 4-month periods of the study. RESULTS: Baseline RMSSD was significantly (p<0.05) associated with lower levels of: fat mass, fat-free mass, subcutaneous abdominal adipose tissue, resting heart rate (HR), resting systolic blood pressure, and exercise HR. Stepwise multiple regression produced a final model (R2 = 0.36) that included only resting HR. The analysis of changes over the three time points of the study found a significant (p = 0.026) time by group interaction, such that RMSSD increased during periods of PT and decreased following cessation of PT. Greater individual increases in response to the PT (p<0.05) were seen in those who had lower pre-PT RMSSD levels, showed the greatest decreases in resting HR, and increased most in vigorous physical activity. The final regression model retained only the change in resting HR as a significant predictor of the changes in the RMSSD (R2 = 0.23). DISCUSSION: Regular exercise that improved fitness and body composition had a favorable effect on PSA in obese children.
Gutin et al. (Sat,) conducted a rct in Obesity (n=79). Physical training vs. No physical training / cessation of training was evaluated on Root mean square of successive differences (RMSSD) as an index of cardiac parasympathetic activity (p=0.026). Physical training significantly increased cardiac parasympathetic activity (RMSSD) in obese children, an effect that reversed upon cessation of training (time by group interaction P=0.026).