DEAR DR. DONOHUE: I am 64 years old and stay fit with daily bike rides, walks, kayaking, swimming in the summer and cross-country skiing in the winter. I feel terrific. I never drink water. I have never felt thirsty in my life. I have been told that everyone should drink several glasses of water a day, but I can’t get into the habit. Should I force myself to do so? I feel that “if it ain’t broke, don’t fix it.” — L.P.

ANSWER: It’s hard to argue against the “if it ain’t broke, don’t fix it” maxim. However, there are two issues in your question: daily hydration needs and exercise hydration needs.

On a daily basis, we require about 2.5 liters (2.6 quarts) of liquid a day. Notice the word “liquid.” All liquids count, not just water. Even solid foods have lots of liquid in them. Many vegetables and fruits are, for the most part, 90 percent liquid. Meats and baked goods contain liquids. The rule that a person should drink eight 8-ounce glasses of water a day is an old rule. It’s not necessary to take in that much water every day. You can let thirst be your guide. At older ages, thirst sensation becomes blunted, and older people have to remind themselves to drink fluids. Perhaps without ever feeling thirsty, you might benefit by drinking a couple of glasses of water. However, you can check your hydration status by the color of your urine. Pale-yellow urine indicates adequate hydration. Dark-yellow urine is a sign that you’re on the dry side and need some liquid. Coffee and tea count as hydrating liquids. Alcohol is a question mark.

Hydration for active athletics and exercise is another matter, particularly in hot weather when there is heavy sweating. You can estimate your fluid loss in these circumstances by weighing yourself before and after exercise. Weight loss that occurs during exercise is liquid weight loss. A decrease of 1 percent to 2 percent in body weight indicates mild dehydration. A decrease of more than 2 percent is a level of dehydration that affects performance. A loss of 9 percent of body weight approaches an emergency situation. If you have lost more than 2 percent of your body weight, drink fluids; plain water will do.

DEAR DR. DONOHUE: Is there any type of exercise a teenager can do before playing high-school soccer? My daughter gets terrible leg cramps during a game and has to come out. She has played soccer for many years. — M.E.

ANSWER: Exercise-induced muscle cramps is a subject about which good scientific knowledge is lacking. Dehydration; loss of sodium, potassium and magnesium; and fatigue have all been incriminated as causes. Another explanation is that people with a tendency to cramp have muscles with increased electrical activity. What to do for that is never stated.

In ironman triathlons — a 3.9 km (2.4 mile) swim, followed by a 180.2 km (111.7 mile) bike race, and finishing with a 42.2 km (26.6 mile) run — up to 20 percent of participants suffer from leg cramps.

Have your daughter try this. Three to four hours before practice or competition, she drinks a sports drink and eats a handful of pretzels. Before she starts, she warms up her leg muscles by running in place, not at a great speed but just enough to get blood flowing to her muscles.

DEAR DR. DONOHUE: I read with interest your article about loss of muscle tissue and a decrease in strength as we get older. I am 72. I jog for 2 or 3 miles five times a week. I also bike outdoors during good weather and use a stationary bike in the winter. Included in my exercise program is stair-climbing.

I wonder if I need to add resistance exercise to my program. I have never lifted weights and wonder if the benefits outweigh the risks. — J.D.

ANSWER: Jogging, biking and stair-climbing count as resistance exercise, muscle-building exercise. You’re propelling body weight.

You could do more body-weight exercises by squatting and rising on your toes. In squatting, don’t touch your buttocks to your heels. Only bend the knees to a level in which the thighs are parallel to the ground.

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

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