People who exercise in the morning, specifically around 10 am “late morning”, have the least risk of heart disease and stroke, according to a study published in the European Journal of Preventive Cardiology.¹

Researchers analysed data of 86,657 adults, aged 42-78 years, from the UK Biobank in this observational study. More than half (58%) of them were women; the mean BMI was 26.6 kg/m2. None of the screened participants had a heart disease at the time of their enrolment. They were instructed to wear a wrist activity tracker device for one week. The objective of the study was to examine the association between timing of daily physical activity and new-onset heart disease i.e., first cardiac-related hospitalization or mortality.

The study also attempted to explore any link between the peak time of activity and incident cardiovascular disease. For this, they categorized the study subjects according to the peak time of their physical activity: midday, early morning (~8 am), late morning (~10 am) and evening (~7 pm). The participants were followed up for a period of 6 years. Midday was taken as the reference group

Data analysis showed that 3707 incident CVD events occurred during the course of the study; 2911 were coronary artery disease and 796 were cases of stroke. When the occurrence of incident cardiovascular disease was examined for a connection with the timing of peak activity, morning time was found to be associated with the least risk of heart disease as well as stroke. This effect was seen regardless of the total physical activity.

Compared to participants with midday peak activity, those who were most active in the early morning lowered their risk of incident coronary artery disease by 11%, while this risk decreased by 16% among those whose peak activity timing was in the late morning (HR 0.84). The late morning group also reduced their risk of incident stroke by 17% (HR 0.83). These effects were particularly more marked in women. The risk for new onset CAD was 22% lower among women who were most active in the early morning and 24% in the late morning vs the reference group. The early morning women also lowered their risk of stroke by 35%. No association with sleep or total activity was observed.

The findings of this study while reiterating the benefits of physical activity also highlight the significance of timing of physical activity or “chronoactivity”. To gain the maximum cardiovascular protection from physical activity, morning time, especially later morning around 10am may be the most advantageous, as shown in this study. Researchers are hopeful that these findings may find a place in the guidelines for physical activity.

Reference

1. Albalak G, et al. Setting your clock: associations between timing of objective physical activity and cardiovascular disease risk in the general population. Eur J Prev Cardiol. 2022 Nov 14;zwac239. doi: 10.1093/eurjpc/zwac239.