The Best Time to Exercise to Lose the Most Weight and Improve Insulin Sensitivity


As a part of my practice I routinely give exercise prescriptions. However, I have not been specific about the best time for exercise, especially when attempting to lose weight or maintain healthy blood sugar.  A fascinating new study from researchers at the Dept. of Biomedical Kinesiology, Leuven, Belgium, revealed that there is actually a “best time” to exercise.  In this study 28 healthy men between the ages of 18 and 25 were assigned to one of three groups.  The first group exercised before eating a carbohydrate-rich breakfast, and drink only water during exercise.  The second group  ate a carbohydrate-rich breakfast before exercising, and drank sugary drinks such as sports drinks during their workout. The third group ate an identical diet but did not exercise at all.  The men who exercised ran and cycled at a strenuous intensity four times a week.  Overall, the men had identical high-calorie, high-fat diets. The primary difference was whether — and most importantly, when – they exercised. The other difference was the type of beverages they drank during exercise. At the end of the trial, the non-exercising control group had gained an average of more than six pounds, and had developed insulin resistance — the precursor to Type 2 diabetes.  Those who ate breakfast prior to hitting the gym gained an average of about three pounds; half the weight gain of those who did not exercise. However, they too had developed insulin resistance.  The only group that gained almost no weight, and showed no signs of insulin resistance were those who exercised before eating breakfast, and drank only water during their workout.  In addition, the type of beverage consumed during exercise can also have a major impact on your weight loss and health goals. According to the study you should avoid all types of sugary drinks, including sports drinks, for up to two hours after your workout because fructose obliterates the growth hormone response.  From the results, it becomes very clear that something as simple as modifying your schedule to exercise before eating your first meal of the day, and not consuming sugary sports drinks can have a very beneficial and protective impact on your health and weight.