Light-Intensity Physical Activity and Sedentary Behavior Are Associated With Blood Pressure Levels in Adolescents

Purpose: To investigate the associations between physical activity (PA) intensities, sedentary behavior (SB), and blood pressure (BP) in adolescents, according to sex. Method: This cross-sectional study involved 95 male and female adolescents aged 15-18 years. Accelerometry was used to measure time spent in light-intensity PA (LPA), moderate to vigorous PA (MVPA), and vigorous PA, and SB. The BP was determined using an automated sphygmomanometer. Statistical analyses included multiple linear regression and command margins. Results: Significant associations were found between systolic BP (SBP) and time spent in LPA (B = -0.08; 95% CI, -0.15 to -0.01) and SB (B = 0.071; 95% CI, 0.004-0.138), albeit only in boys. Furthermore, an interaction was observed between time spent in SB and MVPA for SBP in boys (B = -0.002; 95% CI, -0.004 to -0.0008). The main interaction effect of increasing SBP was a combination of <75 minutes per day of MVPA and up to 600 minutes per day of SB. Conclusions: Increased time in LPA and reduced time spent in SB during the day are associated with lower SBP in male adolescents. Additionally, the relation between SB and SBP was attenuated by MVPA. These findings provide crucial insights for PA recommendations to promote cardiovascular health in adolescents.