Regular exercise can improve insulin sensitivity for at least 72 hours after the last session in people with type 2 diabetes mellitus. This effect may be maintained even after short periods of physical inactivity.
Exercise has been considered one of the most important nonpharmacological strategies for people with diabetes! The benefits promoted by exercise are effective to control not only body weight but also to improve the ability of a molecule named GLUT4, which is responsible for transporting sugar into the muscle cells. Exercise is able to increase the number of GLUT4 molecules, and their ability to carry sugar.
Another important effect of insulin is regarding its ability to control blood sugar levels. The cells of people with non-insulin dependent diabetes (i.e., type 2 diabetes mellitus [T2DM]) are unable to respond to the normal actions of insulin (also known as insulin resistance). Insulin resistance has been associated with hypertension, heart disease, stroke, and cancer. Therefore, researchers in Australia analyzed fourteen studies in order to verify the effect of exercise on the ability of cells to absorb sugar from the blood when stimulated by insulin (also known as insulin sensitivity). To be selected for this meta-analysis, studies should have involved at least three exercise sessions per week, and included measurement of insulin sensitivity.
It was observed that exercise training improved the ability of cells to absorb sugar from the blood. This effect persisted for more than 72 hours after the last exercise session. The authors cited that the American College of Sports Medicine, American Diabetes Association and the American Heart Association recommend performing exercise every 48 hours for people with T2DM. This should be done as an effort to control the blood glucose levels and insulin resistance. However, the authors have doubts about the dose and types of exercise which can result in these benefits, because the studies they analyzed had different modalities, intensities, and durations. However, these studies followed the exercise recommendations (aerobic exercise at moderate to vigorous intensity on 3 to 5 days per week combined with regular vigorous progressive resistance training) for people with T2DM. Some limitations are the small number of studies analyzed, small sample size, differences in the exercise prescription and in the techniques performed to measure insulin sensitivity.
The Australian researchers were able to support the hypothesis that regular exercise improves insulin sensitivity for at least 72 hours after the last session. It is possible that short periods of inactivity may not negatively interfere with this effect.
Written By: Vagner Raso