An interesting article appeared in the American Journal of Clinical Nutrition, July 2013 observes that taking a short walk every half an hour may be more effective at reducing the risk of type 2 diabetes than one brisk 30-minute walk a day.

For the first part of the research, 70 healthy adult volunteers were asked to sit for nine hours. They were given a meal-replacement drink after one hour, four hours and seven hours, and after each of these drinks they had their blood glucose and insulin levels measured to see how well their bodies were absorbing sugar from foods. In the second part, the participants were asked to walk briskly for half an hour before sitting for nine hours. Finally, they sat for nine hours again but this time walked around for precisely one minute 40 seconds every half an hour.

The results showed both post-meal insulin and blood sugar levels were lower following the short walks than after the 30-minute stroll, or when the volunteers did not move at all from their seats. Raised blood sugar and insulin readings are warning signs for the development of type 2 diabetes. The researchers concluded: "Regular activity breaks were more effective than continuous physical activity at decreasing blood sugar and insulin levels in healthy, normal-weight adults."