Morning and afternoon physical activity are better associated with a lower risk of developing Type-2 diabetes, according to a new study, led by researchers including one Indian-origin.

The new research, published in the journal Diabetologia, found no statistically significant association between evening physical activity and risk of Type 2 diabetes.

Physical activity is a preventive factor for Type 2 diabetes, but its timing and consistency (in contrast with overall sum of physical activity) has been relatively unexplored.

Researchers from Harvard University in the US analysed the relationship between morning, afternoon, or evening physical activity and consistency (routine) and risk of Type 2 diabetes.

“Our study showed an association with diabetes risk between morning and afternoon versus evening physical activity. The findings also suggest it is helpful to include some higher-intensity activity to help reduce the risk of developing diabetes and other cardiovascular disease,” said Dr Chirag Patel, Harvard Medical School.

The team included 93,095 participants (mean age 62 years) without a history of Type 2 diabetes who wore a wrist-worn accelerometer for one week. They converted accelerometer information to estimate metabolic equivalent of task (MET) (a common measure of physical activity), adding up MET-hours of total physical activity, including chores, walking, and vigorous activity.

The team observed protective associations of physical activity, with each 1-unit increase in MET being associated with a 10 per cent and 9 per cent reduction in risk of Type 2 diabetes in the morning and afternoon, respectively. However, there was no statistically significant association between evening physical activity and risk of Type 2 diabetes.

The researchers believed that lifestyle factors, such as amount of sleep and dietary intake, would influence the amount of physical activity in the morning, afternoon, and evening undertaken, and therefore the role activity has in diabetes risk.

“The consistency or routine of physical activity was not strongly associated with Type 2 diabetes. In other words, individuals who exercise a smaller amount of time more frequently are at no lesser risk for diabetes than individuals who exercise the same total amount, but with less of a routine,” Dr. Patel said.

“Our findings support that total physical activity, but not its consistency over the week, may be an important factor impacting Type 2 diabetes risk. The timing of activity may play a role in the mitigation of diabetes risk,” he added.