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.

Physical activity moderates the deleterious relationship between cardiovascular disease, or its risk factors, and quality of life: Findings from two population-based cohort studies in Southern Brazil and South Australia.

BACKGROUND: Few studies have investigated the relationship between physical activity (PA) of low intensity and duration with quality of life (QoL) among individuals at risk or with cardiovascular disease (CVD). OBJECTIVES: To investigate whether PA of different intensity and duration moderates the relationship between CVD and its risk factors (obesity, hypertension, diabetes, dyslipidaemia) and QoL in adults. METHODS: Population-based cross-sectional studies using data from the EpiFloripa Cohort Study (Southern Brazil; n = 1,220, 38.8±12.0 years, 48.2% males) and the North West Adelaide Health Study (NWAHS, South Australia; n = 1,661, 43.7±11.1 years, 49.7% males). The physical and psychological domains of QoL were assessed using the WHOQOL-Bref (EpiFloripa) or the SF-36 (NWAHS) questionnaires. The diagnosis of CVD and its risk factors were self-reported. PA was self-reported and quantified by its intensity ["walking" or moderate/vigorous (MVPA)] and duration (none, 1-150, ≥150 min/week). Both studies were analysed separately, and results were adjusted for sociodemographic variables. RESULTS: Participants at risk or with CVD from both studies showed a lower QoL than 'healthy' individuals with a stronger relationship for the physical domain. PA duration showed a direct-trend relationship with QoL, but the associations were stronger for MVPA in both studies. However, when stratified by health status, the magnitude of the association between "walking" duration and a higher physical QoL was greater among those at risk or with CVD compared to 'healthy' individuals. Conversely, among Australians with CVD, MVPA was associated with a better physical QoL only when its duration was ≥150 min/week. All associations were stronger in the NWAHS than in the Brazilian study. CONCLUSIONS: "Walking" was more prevalent than MVPA and was consistently associated with a better physical QoL among those at risk or with CVD. These findings should be considered in the design of public health interventions designed to increase PA and improve QoL.