The Benefits of Exercise for Folks with MG

By Robert L. Ruff, MD, PhD, & Suzanne S. Ruff, Health Psychologist

There are many advantages of exercise for folks with MG. This article will detail some of these benefits, quash some common myths and provide suggestions about pacing yourself when exercising.

Myth busted – "Since weakness can be provoked by activity, exercise makes MG worse."

Exercise does not worsen MG. What is true is that inactivity that may ensue before MG is brought under control, will make it harder for an individual to be active. It is true that folks with MG have fatigable weakness. MG treatments will usually reduce the amount of exerciseinduced fatigue caused by MG, but the person is left with fatigue because that individual is deconditioned. Deconditioning affects the muscles and cardio-pulmonary system. Inactivity converts of fatigue-resistant "red" muscle fibers to fatiguesensitive "white" muscle fibers and reduces the density of blood vessels in muscle. Some treatments for MG, particularly glucocorticoid medications (steroids, prednisone for example) heighten the effects of inactivity on muscle.

The cardiovascular and respiratory systems are also adversely affected by inactivity. Inactivity compromises the ability of the heart to pump blood and the lungs to put oxygen into the blood. Lack of exercise compromises muscle activity and the ability of the cardio-pulmonary system to deliver nutrients and oxygen to tissues. It takes time to regain conditioning. An exercise program should be started only after one has consulted a physician.

Inactivity can lead to type II diabetes mellitus. In type II diabetes, elevated blood sugars occur in a setting of initially high insulin levels. What happens is the tissues of the body become resistant to the action of insulin. The insulin-resistant state causes blood sugars to be elevated. A major target for insulin action is skeletal muscle. Red muscle is sensitive to insulin and readily takes up glucose to help keep blood sugars in an appropriate range.

White muscle is insensitive to insulin and contributes to an insulin-resistant state. Glucocorticoid or prednisone-like medications can also lead to insulin resistance. Exercise can combat the change in muscle composition that leads to insulinresistance and also combat the adverse effects of glucocorticoids on skeletal muscle without reducing the ability of these medications to control MG.

Inactivity can also lead to obesity. Your weight is determined by a balance of how many calories you consume and how much you burn. Inactivity reduces the number of calories burned and can lead to boredom with eating becoming one of the few remaining pleasures. Obesity will lead to insulin resistance and type II diabetes.

Inactivity will also worsen osteoarthritis – sometimes referred to as the arthritis due to injury.

The importance of pacing for maintaining steady level of activity

Folks tend to try to do too much on their "good" days and then to pay for that with loss of energy and soreness for the next several days making those "bad" days. To some extent folks will have "good" and "bad" days due to the day to day variability of conditions such as MG. However, it is important to try to pace oneself to reduce the difference between "good" and "bad" days. It is important to try to do pleasurable activities everyday. One may try to get all of one's necessary work done on a "good" day to the point that you may get your work done, but you are too tired to do much the next several days. Being active for only one day out of several will not improve your activity tolerance. A workable strategy is to not overdo it on "good" days and do something pleasurable every day. Pleasurable tasks distract one from the pain and fatigue associated with activity and increases your activity tolerance. On "bad" days, try to space out what you need to do so that although it takes longer to accomplish a specific task, the task is completed with a minimum of discomfort and fatigue. Try to do some pleasurable things on "bad" days as the pleasurable things will not seem to be so tiring or painful. Think of life as a distance race, not a sprint. Accomplish things over time not just one day and be active every day. If you work at being active every day, you will find that over time you can do more and feel better.

(Taken from the MGFA website)