Taking a break from prolonged periods of sitting to walk every 20 minutes helps reduce the body’s glucose and insulin levels after eating, according to a new study.
Australian researchers found that interrupting prolonged periods of sitting with systematic two-minute breaks of light activity like walking may be beneficial for overweight and obese people's health because physical activity helped their bodies keep glucose and insulin levels down after eating a high calorie meal.
While the results of the study published in the journal Diabetes Care did not show whether glucose and insulin level reductions had any lasting health benefits, researchers said that large glucose and insulin spikes after a meal is linked to a greater risk of heart disease and diabetes.
Lead author David Dunstan, a professor at Baker IDI Heart and Diabetes Institute in Melbourne, Australia conducted a randomized three day trial experiment to evaluate levels of postprandial glucose and insulin of 19 overweight adults divided, each day, into three groups: uninterrupted sitting; seated with two-minute sessions of light-intensity walking every 20 minutes; and seated with two-minute sessions of moderate-intensity walking every 20 minutes.
Participants were asked to sit in the laboratory for seven hours, and after the first two hours they drank a 763-calorie drink high in sugar and fat and then sat for another five hours.
Dunstan and his team found that glucose and insulin levels were significantly reduced in participants on the days where they were in light- and moderate-intensity groups, compared to the days they were in the uninterrupted sitting group.
The days when participants sat without interruption resulted in a surge in blood sugar levels within an hour of drinking the high calorie drink from about 90 milligrams per deciliter (mg/dl) to about 144 mg/dl.
On the days participants were asked to get up every 20 minutes, their levels of blood sugar only rose to about 125 mg/dl.
Researchers said that there was a 24 percent reduction in the total rise in glucose levels in participants who engaged in light physical activity and about a 30 percent drop in total rise in glucose levels in participants who engaged in moderate-intensity activity, compared to those who were in the uninterrupted sitting group.
"Interrupting sitting time with short bouts of light- or moderate-intensity walking lowers postprandial glucose and insulin levels in overweight/obese adults," the authors write. "This may improve glucose metabolism and potentially be an important public health and clinical intervention strategy for reducing cardiovascular risk."