DEAR DR. DONOHUE: I am the coach of a high-school swim team. It is not a big school, and I am not up on the latest in coaching information. I would like to know your view on weightlifting for swimmers. From some, I hear it increases water drag on swimmers and should, therefore, be discouraged. Others say to go for it. What do you say? – P.M.

ANSWER: I side with those who favor weightlifting.

Swimmers – especially those who specialize in one stroke, like the butterfly stroke – overwork some muscles and underwork others. That makes for muscle imbalance, muscle asymmetry and joint injuries. A well-designed weightlifting program can remedy that.

For starters, I have to define the 1 RM – the one repetition maximum. It is the heaviest amount of weight that an athlete can lift comfortably one time. Directions for the correct amounts of weight to be lifted in each program and each exercise hinge on the 1 RM.

For power, so necessary in swim meets, the athlete should choose a weight that is 90 percent of his or her 1 RM and lift that weight three consecutive times. Then the swimmer rests for three to five minutes and performs another set of three lifts. The total number of sets for each exercise is three or four, with three to five minutes of rest between each set.

For endurance, the athlete lifts a weight that is 40 percent to 60 percent of the 1 RM. He or she performs 12 or more consecutive lifts and then takes a 30-to-90-second rest before beginning the second set of lifts. The total number of sets is three to six, with a 30-to-90-second rest break between each set.

Don’t train for power and endurance on the same day. Do err on the side of safety when it comes to determining the amount of weight to be lifted.

DEAR DR. DONOHUE: Please answer this question. My doctor told me to exercise more. I had been doing a dancing routine five days a week. She said that was not enough exercise.

Now I have begun to walk in the pool five times a week for a minimum of 45 minutes each time. This doesn’t seem to get my heart rate up like the dancing routine did. Am I getting enough exercise for my heart by walking in the pool? – C.H.

ANSWER: You are moving large muscles – the legs – continuously for 45 minutes, and that fulfills the criteria for the kind of exercise that benefits heart and blood vessels.

You will not get your heart beating as fast in water as you can with comparable exercise on land. A number of factors are responsible for that. One is that water keeps the body cooler than air does, so the heart does not have to beat as fast in water as it does on land to dissipate the heat generated by exercise.

You can gauge the intensity of your exercise and its benefit by perceived exertion. Instead of counting your heart rate, you can tell the intensity of your exercise by how tough you feel it is – just enough, but not too tough.

If you want to determine a target pulse rate for water exercise, figure out what it would be when doing the same exercise on land and then subtract 13 beats a minute to obtain the comparable pulse rate in water.

DEAR DR. DONOHUE: I have a beautiful daughter who will be 17 in a few months. She is healthy, outgoing, involved in school activities and works part time. The problem is she has thick legs. She has an hourglass figure, and she eats right and works out three or four times a week. Nothing works to slim her legs or give them any definition. They are thick and solid from the thighs down. Can you suggest an exercise or a special diet that would help? – R.C.

ANSWER: I have to be blunt. There is no exercise or diet that sculpts the legs into proportions a person believes is more pleasing. The cause of your daughter’s thick legs resides in her genes.

Only if your daughter was overweight would diet and exercise affect her legs, and even then they would not selectively remove excess tissue from the legs. They would remove it from all body sites.

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.