How a 10-minute bout requirement for physical activity affects guideline adherence estimates, Germany

To examine how adherence to the World Health Organization's (WHO) physical activity guidelines changes with and without the application of a 10-minute bout requirement.

We analysed accelerometry data from the baseline assessment of the German National Cohort, NAKO. Using predefined acceleration thresholds, we classified each participant's volumes of moderate and vigorous intensity physical activity and compared these values with WHO guidelines. We analysed data with and without the 10-minute bout requirement. We used Welch's analysis of variance and equal proportions tests to compare demographic and health characteristics between participants who met the activity guidelines and those who did not.

Of 63 134 participants, 22 226 (35.2%) met the guidelines with the bout requirement, while 62 532 (99.0%) met the guidelines without it. Participants who met the guidelines under each condition differed in demographic and health-related characteristics. For example, mean age was 48.6 years (SD: 13.0) among participants meeting the guidelines with the bout, 50.8 years (SD: 12.2) among those meeting only the guidelines without the bout and 60.8 years (SD: 10.4) among those meeting neither guidelines. Participants meeting the guidelines with the bout had a lower body mass index (25.2 kg/m²; SD: 4.0) than those meeting only the guidelines without the bout (27.0 kg/m²; SD: 5.1) and those meeting neither guidelines (30.6 kg/m²; SD: 7.1).

Removing the 10-minute bout requirement for accelerometry-measured activity volumes substantially increased estimated guideline adherence. The change has implications for interpreting time trends in guideline adherence and alters conclusions about which population subgroups meet the guidelines.