The data is clear - you must exercise appropriately to live longer and feel better. The scientific basis for our seventh recommendation, "Assure Appropriate Daily Exercise," is the topic of this column.

There are two general types of exercise: aerobic and anaerobic. Aerobic exercise uses large muscles and includes activities such as walking. Anaerobic exercise uses muscles against resistance, and includes activities such as weightlifting.
Are all types of exercise equally helpful? Not really. Bench-pressing may make the body strong and beautiful, but does not do much for cardiovascular health. On the other hand, appropriate anaerobic exercise is essential, especially as we get older. It has been reported that 70 percent of 70-year-old women cannot lift a gallon of milk (about 10 pounds). This type of progressive muscle weakness leads to instability and falls. And especially in the elderly, falls are devastating. Exercising with light weights is recommended for most individuals over 65 years of age. Keeping up leg strength by walking up stairs or doing knee bends also is a good idea.

How much exercise is required? The answer has changed. One widely held misconception that the medical profession had for decades was the belief that to be helpful, aerobic exercise had to be performed at at least 70 percent maximal heart rate (220 minus your age estimates maximal heart rate) for 30 minutes, three to four times a week. Studies clearly showed that this amount of exercise is necessary for a training effect, i.e., to increase measured maximal oxygen consumption.
Despite all the talk, hype and commercialism (expensive running shoes, fashionable jogging suits, etc.) surrounding this type of exercise, the public has not accepted it. The time it takes to change clothes, run, shower and change clothes again, takes a commitment and willpower - and unfortunately for most, willpower lasts about three weeks.

The good news is that we now know that the amount and the duration of exercise that one needs for health is different from that needed for a training effect. Studies have shown that the exercise does not have to be as intense nor does it have to be all at once - 10 minutes three times a day is as effective as 30 minutes all at once.
A few daily activities to increase your exercise include: parking your car at the far end of the parking lot; taking the stairs; taking a walk during the lunch break; and working around the house and the yard. What is the ideal daily exercise? Walking or swimming. Studies of retirees have shown a tremendous health benefit from walking at least two miles a day. Not three times a week but every day. (For physicians interested in the references for these statements, they are JAMA 1995; 273:402 and NEJM 1998; 338:94.)

Finally, don't forget stretching. It is important for stability. Most of us do not stretch - and those who do tend to not hold the stretch long enough. Ballerinas hold their stretch for 100 seconds. That is probably not necessary for most of us, but we probably not only need to add stretching to our daily routine, but also to hold the stretch longer.

Can you harm yourself with the wrong kind or amount of exercise? Yes, you can! Just recall the friends you know who "ran for their health," only to end up with one or more joints that are now so painful they can hardly walk, or that had to be replaced. This doesn't happen to everyone, but you should be especially careful if you are overweight or there is a family history of osteoarthritis.

Joint destruction is not the only danger. Ligaments and muscles also can be harmed. You have heard the macho slogan "no pain, no gain." It is totally incorrect. Pushing to pain might get you on the varsity team, but it also may be detrimental to your long-term health. Rather, your slogan should be "sweat, yes, pain, no!" Our pain receptors are there for a reason - to protect us from doing damage to ourselves.

Volumes have been written about exercise for health and well-being. Motivation is another matter. We must pick our priorities and put them into practice. It takes about 30 days for an adult to form a habit. A good place to start a good new habit is by calling Lawton Snyder, M.S., M.B.A., program coordinator of cardiac rehabilitation, at 694-4008.

The team at University Medical Center's Wellness Center will design a personal exercise program to improve your health and reduce your risk for cardiovascular disease.