Type 2 diabetes study: Afternoon exercise tied to blood sugar improvements, Boston researchers find

Those with type 2 diabetes who are planning out their exercise schedule should consider getting in a workout after lunch, according to a new study from Boston researchers.

Type 2 diabetes patients who were physically active in the afternoon saw greater improvements in blood sugar levels than those who were most active at other times of day, the researchers from the Brigham and Joslin Diabetes Center recently found.

“In this study, we show that adults with type 2 diabetes had the greatest improvement in glucose control when they were most active in the afternoon,” said Jingyi Qian, from the Division of Sleep and Circadian Disorders at the Brigham.

“We’ve known that physical activity is beneficial, but what our study adds is a new understanding that timing of activity may be important too,” Qian added.

More than 37 million Americans have diabetes, and 90% to 95% of that population are diagnosed with type 2 diabetes. Doctors recommend that patients with diabetes participate in regular physical activity as a method to manage their blood glucose levels. Elevated blood glucose levels can put people with type 2 diabetes at risk of heart disease, vision impairment, and kidney disease.

This new study from investigators at Brigham and Women’s Hospital and Joslin Diabetes Center uses data from the Look AHEAD (Action for Health in Diabetes) study.

The research team looked at whether physical activity at certain times of day was associated with greater improvement in blood glucose control. Their findings suggest that patients with type 2 diabetes who were physically active in the afternoon had the largest improvements after one year in the trial.

During the study, participants wore a waist accelerometry recording device to measure physical activity. When the Brigham and Joslin team reviewed the data from year 1, they determined that those who engaged in moderate-to-vigorous physical activity in the afternoon had the greatest reduction in blood glucose levels.

In future studies, the team may test their findings experimentally to investigate why the time of day for exercise may influence blood glucose control. From this, the team may be able to provide specific physical activity recommendations for patients.

“Timing does seem to matter,” said Roeland Middelbeek, assistant investigator at Joslin Diabetes Center. “Going forward, we may have more data and experimental evidence for patients to give more personalized recommendations.”