DEAR DR. DONOHUE: I have modified the way I run by leaning forward quite a bit. It makes me run faster because it seems to give me more momentum. I have been told that I am all wet about this. What’s your input? – L.K.

ANSWER: Perhaps your self-devised running style works for you, but it isn’t one recommended for most runners. Leaning forward actually diminishes momentum. It puts strain on the lower back, and you might end up with a sore back. It restricts hip motion, so it should be slowing you down. And it puts abnormal stress on your feet when they hit the ground. All in all, it’s not good form. I can’t explain why it’s working for you, but you should be careful about continuing it if you start to get back, hip or foot pain.

The correct running style is to keep the head straight, looking neither up nor down. If you drop a plumb line from the top of the head, the line should fall around the middle part of your foot. Coaches tell their runners to run tall.

Arms assist a runner in keeping balanced, and they help in propulsion. The elbows should be bent about 90 degrees and swing like pendulums from the shoulders. They shouldn’t cross the midline of the body. They should rise to the chest and fall to the seams of the running shorts.

Hold the hands relaxed with loose wrists. Some say to cup the hands with the thumb touching the forefinger. If this is too much, you can forget it.

DEAR DR. DONOHUE: I would like to know about stair-climbing. How many calories does it burn? I can do it at work, and I get more exercise than I do walking. – K.R.

DEAR DR. DONOHUE: I have a question about stair-climbing. When I am on a break at work, I walk 30 flights of stairs, up and down, in 12 minutes. Is this enough, or do I need to do 60 flights in 24 minutes? I run four times a week (seven miles at a time) plus walk three to four miles every day. – L.M.

ANSWER: Stair-climbing is great exercise. Football players do it all the time in their stadiums. The problem with answering questions about stair-climbing is that there are so many variables involved that estimating calorie-burning and exercise intensity is a rough guess at best.

The factors involved include the height of the steps, a person’s body weight and the speed of climbing.

One estimate states that .4 calorie is burned climbing up and stepping down from one step: .3 calorie for stepping up and .1 for stepping down. It takes 70 steps, using this formula, to burn 28 calories. If 15 steps are one flight, then 70 steps are about 4.7 flights. You can determine for yourself how many calories you want to burn and how many flights that would take.

Another study states that stair-climbing burns .2 calorie per step – .15 for stepping up, .05 for stepping down. This estimate was obtained by measuring calorie burning in men who weighed 150 pounds (70 kg). If you use this criterion, it takes twice the number of steps to burn the same number of calories as are burned using the first formula. I am going to use the first formula.

L.M., you are getting plenty of exercise and calorie-burning with the amount of stair-climbing you are doing right now. You’d double the intensity of the exercise by doubling the time. However, you do so much weekly exercise in other ways that you might be tempting fate. You can overdo the exercise bit, you know.

DEAR DR. DONOHUE: I don’t have weights, but I do have a chinning bar. What muscles am I working? I am 12. – B.P.

ANSWER: If you hold on to the chinning bar with palms facing you, you are exercising the biceps muscle – the big muscle on the front of the upper arm, the one Popeye loves to flex. You’re also exercising chest muscles. If you turn your grip around, you exercise the triceps muscle, the muscle on the back of the upper arm, as well as many back muscles.

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.