A study published in Diabetes Care, a journal of the American Diabetes Association investigates the impact of the timing of moderate to vigorous physical activity (MVPA) on all-cause mortality, cardiovascular disease (CVD) incidence, and microvascular disease (MVD) incidence among adults with obesity, including those with type 2 diabetes (T2D).
Participants were categorized into four groups based on the timing of their physical activity: morning, afternoon, evening, and a reference group that did not engage in regular aerobic bouts. The study observed participants over an average follow-up period of 7.9 years, corresponding to 236,387 person-years in total. During this period, 1,425 deaths were recorded, offering substantial data for analysis.
One of the key findings of this study is the significant reduction in all-cause mortality risk associated with evening MVPA. Participants who engaged in physical activity in the evening showed the lowest mortality risk; this reduction was more pronounced than those observed in the morning and afternoon MVPA groups. These results suggest that the timing of physical activity plays a crucial role in mortality outcomes, with evening exercise providing the most substantial benefits.
For CVD incidence, a similar pattern emerged where evening MVPA was associated with the lowest risk of developing CVD, lower than both the risks observed in morning and afternoon activity. These findings were consistent even among participants diagnosed with obesity and T2D.
An interesting aspect of the study is the dose-response association between the frequency and duration of MVPA bouts and health outcomes. The frequency of MVPA bouts showed a stronger inverse association with mortality and CVD incidence compared to the duration of the bouts. This indicates that regular engagement in short bouts of physical activity may be more beneficial than less frequent, longer sessions.
The study's findings are particularly relevant for adults with obesity and T2D, who often face challenges in managing blood glucose levels and cardiovascular risk. The evening timing of MVPA may offer the greatest benefits in terms of improving insulin sensitivity and glycemic control, which are critical factors in managing these conditions. We were surprised by the gap, we didn’t think the risk reduction would be as pronounced as it was,” said Dr. Sabag, an exercise physiologist and one of the investigators in this study, to the New York Times.
Tthis study underscores the importance of not only engaging in regular physical activity but also considering the timing of such activity to maximize health benefits. Evening MVPA appears to be the most advantageous for reducing all-cause mortality and CVD incidence among adults with obesity, including those with T2D.
Sources: Diabetes Care, New York Times