Exercise, regardless of the amount or intensity, produces similar reductions in abdominal obesity, but only high-amount, high-intensity exercise showed improvements in 2-hour glucose readings, according to a 24-week trial of 300 abdominally obese adults.

Subjects were split into a control group and 3 groups told to exercise 5 times a week at varying amounts and intensity based on maximum oxygen capacity (VO₂ peak)—low-amount, low-intensity (LALI); high-amount, low-intensity (HALI); and high-amount, high-intensity (HAHI)—with the following results:

Citation: Ross R, Hudson R, Stotz PJ, Lam M. Effects of exercise amount and intensity on abdominal obesity and glucose tolerance in obese adults: a randomized trial. Ann Intern Med. 2015;162(5):325-334. doi: 10.7326/M14-1189.

Commentary: Current recommendations and traditional exercise programs focus on achieving 150 minutes of moderate exercise a week. Over the last few years there has been increasing interest on the potential benefits of high-intensity training above that found with regular training alone.¹ One type of high-intensity training, called high intensity interval training (HIIT), alternates periods of high intensity training with periods of lower intensity training with the goal of achieving a better workout in less time. The current study suggests that it is not just the amount of exercise, but also the intensity of exercise, that influences the beneficial effects of the exercise performed. —Neil Skolnik, MD

1. Francois ME, Little JP. Effectiveness and safety of high-intensity interval training in patients with type 2 diabetes. Diabetes Spectr. 2015;28(1):39-44. doi: 10.2337/diaspect.28.1.39.