Associations Between Substitution of Sedentary Behavior Patterns With Physical Activity and Cardiovascular Risk Factors in Adolescents: A 3-Year Longitudinal Study.

ABSTRACT

BACKGROUND: Little is known on how the substitution of time spent in sedentary behavior (SB) patterns with time spent in physical activity impacts cardiovascular risk factors during adolescence. The study aimed to investigate how the substitution of time spent in SB and sedentary bouts with time spent in different physical activity intensities was associated with longitudinal changes in cardiovascular risk factors in analyses stratified by sex. METHODS: This is a prospective cohort study with a mean follow-up period of 3.2 (±0.34) years, involving 109 (60 girls and 49 boys) Brazilian adolescents. Body mass index, waist circumference, and cardiorespiratory fitness were the cardiovascular risk factors considered. A cardiovascular risk score was calculated. Sedentary bouts, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) were measured by accelerometers. Multivariate linear regression models adopting the isotemporal substitution were used to analyze the association between substitution of 10 minutes per day of sedentary bouts with LPA and MVPA and risk factors. All analyses considered 5% significance levels. RESULTS: Substitutions of SB, short and long bouts, with MVPA were associated with higher cardiorespiratory fitness in boys (ß = 0.077; 95% confidence interval, 0.001 to 0.55; ß = 0.076; 95% confidence interval, 0.003 to 0.154; and ß = 0.084; 95% confidence interval, 0.001 to 0.167, respectively). No associations were observed when analyses involved substitution of sedentary bouts with LPA, adiposity, cardiovascular risk score, and girls. CONCLUSIONS: Substituting SB bouts with MVPA appears to favorably influence changes of cardiorespiratory fitness in boys during adolescence. Greater benefits appear to occur when longer sedentary bouts are substituted by MVPA.