DEAR DR. DONOHUE: As a senior citizen who has been involved with weight training for most of his life, I find that my strength is slowly ebbing. I am consistent in my training routine. I have been told that my DHEA is but a fraction of what it used to be, and that I should take a DHEA supplement. What is it, and would it help revitalize me and my training program? – G.B.

ANSWER: DHEA, dehyrdroepiandrosterone, is weak male hormone naturally produced by the adrenal glands. It reaches peak production in young adulthood and then the production begins to wane. By age 70, its output is only 10 percent to 20 percent of what it was in peak production years. For all of us, our DHEA is only a fraction of what it used to be.

DHEA is touted for more than 20 conditions, including muscle wasting, osteoporosis, heart disease, depression, aging reversal and erectile dysfunction. It’s hard to believe that one hormone – whose role in health and illness is still vague after decades of study – can do so much for so many.

Tantalizing clues, that it is helpful in some situations. For instance, it has shown some promise in getting rid of abdominal fat. Its success in meeting the hype of other claims has been inconsistent and controversial.

DHEA is sold as a supplement and is not a drug. No official agency checks for its quality and for the actual DHEA content of individual brands.

Potential side effects could be hair loss, acne and the appearance of facial and chest hair in women. Doctors wonder if it might foster growth of the prostate gland and of prostate cancer. Neither has been proven to happen.

Most experts tell us there is no justification for healthy older people to use it.

DEAR DR. DONOHUE: I am 80 years old and exercise at the gym for an hour, three times a week. This is in addition to shoveling snow off our walk, cross-country skiing and kayaking in the summer. I feel fine, but I wonder where my limit is? How do I know if I am doing too much? – J.O.

ANSWER: Accurately finding the limit of an individual’s exercise tolerance can be achieved only through special testing, such as a treadmill test.

You can be pretty sure you’re not overdoing if you can continue to talk during exercise and if the exercise doesn’t leave you completely wiped out. Some people keep repeating the Pledge of Allegiance during their exercise sessions. If they get too breathless to do so, they stop and rest. You don’t have to recite the Pledge; you can talk to a friend or to yourself.

Count your pulse. People who are 80 should not get their pulse rate much higher than 100 unless the doctor has cleared them for more strenuous exercise. However, you have been performing your exercises for many years, and they apparently haven’t fazed you.

You should be careful with the snow shoveling. Can’t you get someone else to do that? It’s extremely taxing work. You use both the upper and the lower body, and many older people have suffered a heart attack while pushing snow off their walks. I wouldn’t do it if I were you, unless I had objective evidence that it could not hurt me. Objective evidence would be a stress test.

DEAR DR. DONOHUE: I realize I must exercise, so I walk. When I walk at about 3.5 mph to get my heart rate up and try to maintain it at that elevated rate for 30 minutes, then my knees ache for the rest of the day. It’s a dilemma. To benefit my heart, I have to pay a price in the knees. What do you suggest? – J.B.

ANSWER: Try dividing that 30-minute session into three 10-minute sessions with hours of rest between each exercise period. That might spare your knees.

Or have you considered other exercises, such as swimming or biking? Try a bike out before you buy one. It can be hard on knees too.

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

Only subscribers are eligible to post comments. Please subscribe or to participate in the conversation. Here’s why.

Use the form below to reset your password. When you've submitted your account email, we will send an email with a reset code.