Benefits of Regular Exercise
- October 2007

It is well-established that exercise training is a beneficial adjuvant in the management of diabetes mellitus. Regular exercise in both diabetic and non-diabetic populations can delay the typical age-related diseases, thus improving lifestyle. Regular exercise can also reduce the incidence heart failure and even prevent the onset of Type 2 diabetes.

In several experimental research models of diabetes, the survival rate following an acute heart attack and susceptibility to severe arrhythmias can be prevented by regular exercise. Heart function and the ability of the heart to respond to stimulation to naturally occurring hormones and neurotransmitters can also be improved with exercise. Several beneficial effects of exercise have been proposed to account for these favorable effects on the heart, including:

• A reduction in both body weight and fat weight
• An improved cholesterol profile
• Better glycemic control, and
• Improved energy production in various muscle cells.

Several body tissues, such as skeletal muscles, have a greater ability to use glucose as a source of energy. Recent studies show that glucose “entry” proteins (GLUTs) in the heart are increased following exercise. These proteins are essential for the uptake of sugars by the heart and are important in maintaining a normal glucose level.

The level of these GLUT proteins is abnormally low in hearts from diabetic animals, contributing to hyperglycemia and subsequent disturbances in cardiac function. A low protein level also reduces the heart’s capacity to use sugar as an energy source and increases the susceptibility of the diabetic heart to damage in conditions of oxygen deprivation.

In a recent study from our laboratory, we found that regular exercise training of moderate intensity on a treadmill in experimental diabetes, not only improved heart function and the heart’s tolerance to heart attack, but also improved the ability of the heart to use more sugars for energy.

In doing so, regular exercise actually switched the abnormal energy pattern to a normal pattern such that the heart did not entirely rely on fats as energy.

It is clear that heart function in diabetes can be improved through by regular exercise. Although several beneficial mechanisms of exercise have been reported to date, the enhanced ability of the exercise-trained heart to utilize more sugar as a source of energy is protective in preventing deteriorations in heart function and could potentially be another mechanism explaining the benefits of training in patients with diabetes.

Reproduced with permission - this article first appeared in DESA Challenge Newsletter - Fall 2004.