DEAR DR. DONOHUE: I live in the Snow Belt. My husband insists on shoveling our walks and driveway, and that amounts to an hour or more of hard work. He gets no exercise during the year. He’s 57 and overweight. I think the snow shoveling is going to give him a heart attack. He’s an alpha male and refuses to listen to me. Am I overdramatizing this? – B.H.

ANSWER: Not at all. You’re being sensible. Emergency-department doctors brace themselves for a rush of heart attacks after the winter’s first snow. Your husband has a profile that identifies him as a prime snow-shoveling heart attack risk.

Even with a light snow, an hour of shoveling burns about 480 calories, the equivalent of playing nonstop, singles tennis for a full hour. Shoveling heavier snow requires 660 calories an hour, and that puts it on a par with an hour of vigorous basketball and handball.

Your husband is not a conditioned athlete. He’s foolish to risk a heart catastrophe by shoveling snow.

Snow shoveling has some hidden, unappreciated risks. For one, pushing show with a shovel and trying to lift the shovel entail isometric muscle contractions. An isometric contraction is one in which muscles don’t contract or lengthen when they’re tensed. Such contractions raise blood pressure and strain the heart. Second, contending with the cold is another heart stress.

Even alpha males have heart attacks.

DEAR DR. DONOHUE: Please answer this question. When exercising to improve muscle tone and lose weight, is it better for a person to have a light meal or to work out on an empty stomach?

When a person works out on an empty stomach, is muscle protein broken down and muscle tissue lost rather than more muscle being built?

If you eat before working out, are the nutrients and calories in the just eaten food stored as fat?

I have heard it both ways. Which is true? – T.H.

ANSWER: It takes hours for the calories and nutrients in just-eaten food to get into the blood and become a source of fuel for exercise and a source of nutrients for muscle building, so they don’t enter into the picture quite as rapidly as you suggest. The exception is simple carbohydrates, which do get into the blood quickly and can be used as fuel.

Exercise breaks down muscle, regardless of the state of the stomach. The day after exercise, the body repairs and builds more muscle tissue. That’s why bodybuilders do not exercise the same muscles on consecutive days.

If people are famished when they work out, they limit their ability to perform, and they have shortened their endurance capability. A snack before workout in those circumstances provides fuel for them to keep at their exercise for an acceptable amount of time. On the other hand, eating a large meal diverts blood from exercising muscles to the digestive tract. That interferes with optimum performance.

Eating shortly after exercise is said to permit a greater incorporation of protein into muscle and enhance muscle building. “Shortly” is an hour or so.

DEAR DR. DONOHUE: I’m concerned about my 14-year-old granddaughter. Her pulse rate is in the high 90s at rest. She’s been a gymnast since age 5 and is active. Her sprinting is fine, but endurance running is impossible for her. Could that be due to her rapid heartbeat? – S.B.

ANSWER: The average resting heart rate for a 14-year-old is 55 to 85, but the range is 55 to 100. For an athletic youngster, she does have a somewhat fast, but not abnormal, heart rate. Athletes almost always have a slow heartbeat, often in the 40s. Her faster rate isn’t an explanation for her lack of endurance. Genetics is. She has muscles that permit quickness but don’t permit endurance.

The next time she sees a doctor, have the doctor examine her closely to see if the fast beat might be a sign of something slightly off normal, like too much thyroid hormone.

DEAR DR. DONOHUE: I have had cellulitis, a bacterial infection of the skin, on my left arm more than once. I also have lymphedema of that arm. I had my left breast removed for cancer, and I understand that the lymphedema is related to this. What can I do for both? – Anon.

ANSWER: Lymphedema is swelling of an arm or leg due to a disruption of lymph vessels and lymph nodes. Lymph is fluid that oozes out of the circulation to bathe body cells. Lymph vessels vacuum up that fluid and return it to the circulation. On its way back, the fluid passes through lymph nodes, where germs and foreign material are filtered out.

After extensive breast surgery during which lymph channels and lymph nodes have to be removed, the return of lymph fluid to the general circulation is greatly disturbed, and the arm often becomes congested with fluid – it swells. That makes the skin of the arm susceptible to infection – cellulitis.

If you can get the fluid out of the arm, you’ll solve both the swelling and the cellulitis. Therapists trained in “decongestive” massage can knead the fluid out of the arm. They use light massage strokes to achieve that. Pneumatic pumps can also push fluid out of a swollen arm.

Compression sleeves, which firmly and constantly squeeze the arm, can prevent the fluid from returning.

The same therapists who are skilled in decongestive massage can teach their patients exercises that promote fluid drainage out of the arm.

Your doctor or local hospital can put you in touch with one of these health care workers. Or you can contact the National Lymphedema Network, a foundation that serves people with this condition. The foundation’s toll-free number is 1-800-541-3259, and its Web site is www .lymphnet.org.

The pamphlet on lymphedema and edema (another swelling problem due to fluid retention) offers more information on the causes of and treatments for both disorders. Readers can obtain a copy by writing: Dr. Donohue – No. 106, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com