Associations between the timing of 24 h physical activity and diabetes mellitus: results from a nationally representative sample of the US population – published online 21/02/2025

Qian Xiao, Qiuyu Feng, Martin K. Rutter, Gali Albalak, Heming Wang, Raymond Noordam

Physical activity is well-known to be critical for maintaining metabolic health. Growing evidence suggests that the advantage of physical activity may vary across the 24 h period. In this issue, Xiao et al (https://doi.org/10.1007/s00125-025-06368-9) use a nationally representative sample of American adults to examine the associations between hourly physical activity levels and diabetes and glycaemic biomarkers. The authors observed that higher levels of physical activity in late morning and mid-to-late afternoon were associated with lower odds of diabetes, with similar results being observed for the measures of glycaemic control. In contrast, a higher level of activity at night was associated with higher odds of diabetes. These results suggest that the timing of physical activity may have an important role in metabolic health. Future studies should examine if scheduling exercise in particular time windows can maximise its metabolic benefit. The authors suggest that these results may also help with the development of digital biomarkers using data from wearable devices for use in diabetes risk prediction and disease management in the clinical setting.