The Dose–Response Relationship Between Physical Activity and Cardiometabolic Health in Young Adults

Purpose: Guidelines recommend 150 minutes of weekly moderate-to-vigorous physical activity (MVPA) for all adults, although physical activity level correlation with cardiometabolic health is not well characterized for young adults. We determined the dose–response relationship of MVPA on measures of cardiometabolic health in young adults. Methods: We examined young adults (aged 20–29 years; N = 5,395, 47.9% female) in the 2003–2016 National Health and Nutrition Examination Survey. Exposures were objective (accelerometer based) and self-reported weekly mean minutes of MVPA. Cardiometabolic outcome measures were body mass index (BMI), high-density lipoprotein (HDL), total cholesterol, systolic blood pressure, and diastolic blood pressure. The dose–response relationships were assessed with unadjusted spline analyses. Sex-stratified outcomes were modeled using multivariable linear regression with mean estimated change presented for 150-minute dose increases of MVPA. Results: Among females, associations between objective activity and cardiometabolic measures were all linear. Compared with no activity, 150 minutes of objective activity was associated with a lower BMI (−1.37 kg/m²) and total cholesterol (−4.89 mg/dL), whereas 150 minutes of self-reported activity was associated with a higher HDL (1 mg/dL) and lower diastolic blood pressure (−.42 mm Hg). Among males, an inflection point was identified in the dose–response curves for objective activity with BMI around 100 minutes. Compared with no activity, 150 self-reported minutes was associated with lower BMI (−.26 kg/m²), higher HDL (.52 mg/dL), and lower total cholesterol (−1.35 mg/dL). Conclusions: The dose–response relationships between physical activity and cardiometabolic markers in young adults were predominantly linear, supporting public health calls for any increase in physical activity in this population.