The Dose-Response Relationship Between Physical Activity and Cardiometabolic Health in Adolescents

Introduction: This study examines the dose-response relationship between moderate-to-vigorous physical activity and cardiometabolic measures in adolescents. Methods: Cross-sectional spline analyses were performed using 2003-2016 National Health and Nutrition Examination Survey data among adolescents (aged 12-19 years, N=9,195) on objectively measured (2003-2006) and self-reported (2007-2016) weekly mean minutes of moderate-to-vigorous physical activity and cardiometabolic measures (systolic and diastolic blood pressure, total cholesterol, high-density lipoprotein, BMI, and cardiorespiratory fitness). Inflection points were determined for nonlinear relationships. Results: For objective moderate-to-vigorous physical activity, female adolescents had significant nonlinear associations with inflection points at 90 minutes/week for BMI percentile and systolic blood pressure. Male adolescents had inflection points at 150 weekly minutes of objective activity for BMI percentile and cardiorespiratory fitness. BMI percentile was about 7% lower for female and male adolescents at 150 weekly minutes of objectively measured moderate-to-vigorous physical activity than at 0 minutes. For self-reported moderate-to-vigorous physical activity, inflection points were at 375 minutes/week (diastolic blood pressure for female adolescents) and 500 minutes/week (systolic blood pressure for male adolescents). Conclusions: Among several significant dose-response relationships between physical activity and cardiometabolic health in adolescents, consistent and often nonlinear relationships were identified for BMI, with inflection points at 90-150 minutes of objective moderate-to-vigorous physical activity. Notable differences in associations and linearity were identified by sex and physical activity measure (objective or self-reported). These results support calls for any increase in physical activity among adolescents and suggest that recommendations closer to the adult guidelines of 150 weekly minutes of physical activity may be health promoting and more attainable for youth than the current recommendation of 420 weekly minutes. (C) 2020 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.