A simple soft drink could be the key to helping people with the exercise-related disorder called McArdle's disease, researchers say. McArdle's disease is characterized by a low tolerance for exercise and a high risk of activity-related muscle injury. Researchers at the UT Southwestern Medical Center at Dallas say McArdle's disease, a muscle disorder, was first defined in the 1950s and results from a deficiency of an enzyme that breaks down muscle glycogen -- a stored form of carbohydrate that is an important anaerobic fuel and is critical for normal oxidative metabolism. "When there is no glycogen available, as is the case in McArdle's disease, patients have a very low oxidative capacity and rapidly fatigue with modest exercise such as walking up a slight incline," says UT's Dr. Ronald Haller. "By using an oral source of glucose -- the equivalent of a soft drink -- we show in this study that these patients are able to undertake exercise more easily, especially in the first eight to 10 minutes of physical activity. That's important because it's in that period that they are particularly vulnerable to muscle injury."

SMOKING CAUSES PVD

Another reason to keep that New Year's resolution to quit smoking is that it causes hardening of the arteries in the legs, a life-threatening condition. Also called peripheral vascular disease, this condition is caused by atherosclerosis, which often is due to smoking, researchers say. The hardened arteries restrict blood flow to the legs, which can lead to leg pain while walking. The pain associated with PVD is an early warning sign of blocked arteries throughout the body that can result in stroke or heart attack. PVD also can lead to gangrene or amputation. Diagnosis is simple -- physicians can perform a pain-free screening known as an ankle brachial index, which compares the blood pressure in the arm to that in the ankle. Those at risk also can be diagnosed with an X-ray that highlights blocked arteries.

READING THE FOOD LABEL

How you read the nutritional label on foods is important to your diet, say University of Michigan Health Systems researchers. Registered dietitian Holly Scherer says when trying to manage your weight or a chronic disease, such as heart disease or diabetes, label reading can help you make informed, healthier choices. As you are looking at the Nutrition Facts label on the food product begin reading at the top with the serving size and number of servings per package. Compare the serving size to how much you eat. If you eat double the serving size, then you need to double the calories and other nutrient numbers, including the percent daily value. The nutrients are ordered from what you should limit, such as fat, cholesterol, and sodium, to what is needed, such as dietary fiber, vitamins A and C, calcium and iron.

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(EDITORS: For more information on EXERCISE, contact Rachel Horton at (214) 648-3404 or rachel.horton@utsouthwestern.edu. For SMOKERS, contact Emily Oehler Murdoch at (703) 460-5572 or Emily@SIRweb.org. For LABELS, Erin Block at (734) 764-2220 or eblock@umich.edu)