Meeting Bouted versus Non-Bouted Physical Activity Guidelines and Health Outcomes in CARDIA

Moderate-to-vigorous intensity physical activity (MVPA) guidelines recommend ≥150 minutes/week. Initial guidelines required bouts lasting ≥10 minutes, yet recent guidelines include non-bouted MVPA, despite less established benefits. This analysis sought to compare associations of meeting bouted vs. non-bouted MVPA guidelines on incident hypertension, diabetes, ≥10% weight gain, and cardiorespiratory endurance.

This secondary analysis in the CARDIA cohort study used 15-year follow-up data during midlife. Participants (n=1,924) recruited from four U.S. centers wore an ActiGraph 7164 when 38-55 years old. Accelerometer data were used to define three groups: below guidelines, meeting non-bouted guidelines only, and meeting bouted guidelines. Incident stage 2 hypertension, diabetes, and ≥10% weight gain were assessed during clinical visits at baseline and 5-, 10-, and 15-year follow-up. Follow-up cardiorespiratory endurance was estimated by a 6-minute walk test (6MWT) at the 15-year follow-up. Associations between MVPA guideline group and outcomes were evaluated using survival analysis or ordinal logistic regression in nested models with progressive covariate adjustment.

Mean MVPA differed across groups: below guidelines, 93±36 minutes/week; non-bouted guidelines, 291±120 minutes/week; bouted guidelines, 551±530 minutes/week (p<0.001). Prior to adjustment, hypertension-free, diabetes-free, and ≥10% weight gain-free survival, and follow-up endurance were higher in those meeting bouted guidelines compared to other groups. After covariate adjustment, meeting bouted guidelines remained associated with lower risk of ≥10% weight gain (hazard ratio, 0.66; 95% CI, 0.48, 0.92) and higher endurance (odds ratio, 2.20; 95% CI, 1.47, 3.30). When meeting guidelines and controlling for MVPA volume, a greater proportion of bouted vs. non-bouted MVPA was associated with higher endurance only.

Meeting recommendations with bouted MVPA compared to non-bouted MVPA may provide greater health benefits for weight control and endurance.