HEATHER, athlete and personal trainer: Exercise helps manage coronary heart disease, lower high blood pressure, and reduce the risk of diabetes and obesity. It also helps manage mental illness and reduce the risk of colon cancer and stroke.

There is great debate, however, over which form of exercise - strength training or aerobic training - is the most beneficial.

Studies show that aerobics help lower the resting heart rate, lower triglycerides and positively affect blood lipid profiles. Studies also indicate that strength training improves bone density and glucose metabolism, and decreases body weight and fat mass.

Both play a strong role in the prevention of non-insulin-dependent mellitus. But controversy has arisen in the fitness industry as researchers are finding that long-term participants of aerobics training are not getting the aesthetic results they seek and are suffering more injuries than those who rely on strength training. Advocates of strength training claim that high-force activity such as running damages knees, hips and the back. Additionally, experts claim that for every pound of lean muscle mass created through strength training, the human body will burn an additional 75 to 100 calories per day while at rest.

So, which is better strength training or aerobics?

As I stated in last week's column, whatever form of exercise you choose, there must be a level of progressive resistance. The human body is a magnificent machine and will adapt to the stimulus that is presented. Simply walking one or two miles a day with the same pace and same level of intensity, while better than nothing, does not challenge the body cardiovascularly. Likewise, lifting 10-pound weights, every other day, in the same exercise routine will yield no significant strength or muscle mass gains after the initial inception of the program.

Additionally, one modality of exercise will not be an end all prescription for fitness success. Your fitness regimen should include cardiovascular, strength, and flexibility components.

Focus on one component at a time and progressively increase its intensity. Remember, an extreme of anything places your body at risk for injury. Strength training the front side of your body, otherwise known as "the beach muscles," while ignoring the back side places your joints and body at risk for injury.

Likewise, running five to 10 miles per day for most people is an extreme situation and will result in an overuse injury.

I personally strength train two to three times per week, using a high-intensity protocol. This type of program has been shown to be the most effective for building lean muscle mass, while yielding the least injuries. I do cardiovascular training three to four times per week for 30 to 40 minutes at a moderate intensity with various modalities. Finally, I try to participate in a formal yoga class once a week and work on flexibility in general at least twice a week.

Find a balanced program that works for you. The studies are consistent in that exercise is one of the many controllable keys to better health.

Posted February 19, 2003 04:16 PM