Moderate to vigorous physical activity helps improve cardiovascular health in people with type 2 diabetes no matter when it takes place, but greater benefits are linked with certain times of the day, according to a new study published in the journal Diabetes Care.
In a study known as Look AHEAD, 2,153 participants with type 2 diabetes wore a device on their hip to track their physical activity for seven days. Researchers looked at how often participants engaged in bouts of moderate to vigorous activity, defined as 3 METs/minute (a measure of metabolic activity) or higher for at least 10 minutes. At the end of the study, participants’ cardiorespiratory fitness was measured in an exercise test.
Participants were grouped into six categories based on when they had bouts of moderate to vigorous activity. Four of these groups included participants who had 50% of more of their active bouts during a specific time of day: morning, midday, afternoon or evening. The fifth group included people who didn’t have at least 50% of their active bouts during a single time of day, and the sixth group included people who had active bouts on only one day, or no days, out of the seven days.
To get cutting-edge diabetes news, strategies for blood glucose management, nutrition tips, healthy recipes, and more delivered straight to your inbox, sign up for our free newsletter!
Timing of physical activity
The researchers found that cardiorespiratory fitness was “highly associated” with the timing of active bouts, independent of the total number of active bouts during the week and their intensity. But there was an important twist to this finding — the relationship of activity timing to fitness was different in women and men. In women, the least fit group were those whose activity bouts didn’t fall mostly at one time of day. In men, the least fit group were those who tended to get their activity during midday. Based on their Framingham risk score (FRS) — an estimate of how likely someone is to have a cardiovascular event, like a heart attack or stroke — men who were active in the morning had the highest cardiovascular risk, while there was no link between activity timing and this risk in women.
Despite the clear links between the timing of physical activity and cardiovascular fitness, the researchers noted that “Prospective studies are needed to determine the impacts of [activity] timing on cardiovascular health.” In other words, it isn’t clear whether getting physical activity at certain times of the day affected participants’ fitness level, or whether their fitness level somehow helped determine the time of day when they got the most physical activity.
Until more research makes the answer to this question clear, it’s probably more important to focus on getting more physical activity at any time of day, and to choose the timing based on how it affects your blood glucose control and your mood, and how it fits into your schedule.
Want to learn more about exercising with diabetes? Read “Add Movement to Your Life,” “Picking the Right Activity to Meet Your Fitness Goals” and “Seven Ways to Have Fun Exercising.”