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.
RCT Entities:
OBJECTIVE: Heart rate variability provides non-invasive information about cardiac parasympathetic activity (PSA). We determined in obesechildren: (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. Obesechildren (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 obesechildren.
Authors: Kristen Hedger Archbold; Nathan L Johnson; James L Goodwin; Carol L Rosen; Stuart F Quan Journal: J Clin Sleep Med Date: 2010-02-15 Impact factor: 4.062
Authors: Abbey Alkon; Kim G Harley; Torsten B Neilands; Katelyn Tambellini; Robert H Lustig; W Thomas Boyce; Brenda Eskenazi Journal: Child Obes Date: 2014-04-18 Impact factor: 2.992
Authors: Melinda Millard-Stafford; Jeffrey S Becasen; Michael W Beets; Allison J Nihiser; Sarah M Lee; Janet E Fulton Journal: Kinesiol Rev (Champaign) Date: 2013-11