DEAR DR. DONOHUE: I am a very busy executive and have to parcel my time carefully because of so many demands. What is the exact amount of exercise time necessary for a true health benefit? I am 45 years old and have a yearly corporate physical. I am told I am in good health, and no limitations have been placed on what I can or cannot do. I am 6 feet 1 inch tall and weigh 175 pounds. – A.A.

ANSWER:
I would like to know the exact answer to your question, too. I can give you approximations. As a rule, the more time you spend exercising, the better off you are.

Burning 1,000 more calories a week over and above what you are accustomed to burning in your daily activities definitely increases your chances of living a longer life. To make this clearer, I’ll break that requirement down into walking examples.

Walking at a speed of a mile in 30 minutes, you have to walk 4.5 hours a week.

If you pick up the pace and walk a mile in 17 minutes (3.5 miles per hour), then you have to walk for only 2.7 hours a week to benefit your heart.

These are only rough guidelines. Most authorities say to get at least 30 minutes of exercise on most, if not all, days of the week. That exercise doesn’t have to be done in one session. It’s OK to break it up into three 10-minute sessions. Brisk walking is considered adequate exercise.

I do have to add something about strength training. It should be a part of every exercise program for people of all ages. I know it sounds foolish to ask a woman in her 90s to begin a weightlifting program, but some sort of strength exercise ought to be a part of everyone’s fitness program, regardless of age.

DEAR DR. DONOHUE: I pulled a shoulder while doing a bench press. I stopped all exercise for two months. I started again, and my shoulder hurts just as much as it did two months ago. Now even when I lift light loads it hurts. Did I just pull something? – R.A.

ANSWER:
By two months, a pulled muscle, tendon or ligament ought to have healed. I don’t want to play guessing games with your shoulder. You’ve got to be examined. Obviously this isn’t something that’s going to heal on its own.

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 at P.O. Box 536475, Orlando, FL 32853-6475.

Readers may also order health newsletters from www.rbmamall.com.

DEAR DR. DONOHUE: In one of your columns, you said that walking up stairs is equal to a 20-minute mile. My skeptical friends don’t believe this. Can you quote your source so I can convince them? – K.G.

ANSWER:
I might have misled you. What I said was that stair climbing is the equivalent of running a mile in 11 minutes. That means you have to climb stairs for that length of time – 11 minutes – not climb only one flight.

Pushing your body upward to the next step is two to three times more demanding than taking a step forward horizontally on the ground. Stair climbing is quite taxing. If it weren’t, you wouldn’t see athletes from all over the country running up and down the stairs at their stadiums.

One rough way of determining the calorie cost of stair climbing is to divide your weight by 50 to find the number of calories burned in one minute of climbing one flight of 15 steps.

For a specific estimate, you need to know the height of the steps, the weight of the person and the speed in climbing the stairs. As a rule of thumb, it takes 0.15 calories to go up one step and 0.05 calories to come down one step.

Your friends can look for confirmation of this on the Web. Search for “stair climbing.” I got the information from Running and FitNews, Vol. 7, No. 12 and from Medicine and Science in Sports and Exercise, April 2002.


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