Heart rate variability in XXXX @entity1 : relations to total body and visceral adiposity, and changes with physical training and detraining.

@entity1 @entity551 @entity3457 @entity28
OBJECTIVE: Heart rate variability provides non-invasive information about cardiac @entity3457 ( @entity3457 ). We determined in @entity28 @entity1 : (1) relations of baseline @entity3457 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 @entity3457 to the PT. RESEARCH METHODS AND PROCEDURES: The root mean square of successive differences (RMSSD) was the index of @entity3457 . Obese @entity1 (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 @entity551 , 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 @entity3457 in @entity28 @entity1 .
