The Cooper Institute of Aerobics Research

I've long been an admirer of Dr. Kenneth Cooper who, in my opinion did more to establish the importance of physical activity as part of a healthy lifestyle than any one in the Western World. Dr. Cooper gave us the word Aerobics, he took the adjective aerobic, meaning with oxygen, added an 's' and created the noun aerobics. His book publisher told him that people would never relate to the name and asked him to change the title of his first book, but he stayed with "Aerobics" and sold multiple millions of copies. Dr. Cooper has now established a major campus in Dallas which includes a state of the art fitness center, a superb preventive medicine practice, two on site hotels for conducting residential courses and the Cooper Institute for Aerobics Research which publishes more refereed articles than any university in the field of health and fitness related research.

I spent a very rewarding sabbatical leave at the Cooper Institute and have brought Dr. Cooper and Dr. Steven Blair to Victoria to share their expertise with the UVic students and the general public. A major initiative created at the Cooper Institute is the Fitnessgram which is becoming the definitive tool for assessing the fitness of school children in North America and providing guidance for improved performance. The Fitnessgram Board met recently in Victoria and I was able to renew acquaintances with Dr. Steven Blair and C.E.O. Dr. Charles Sterling. Future editions of WELL will be proud to include our Cooper Watch in which we bring you a summary of some of the cutting edge research from the Cooper Institute.

Martin Collis

by Steven Blair, P.E.D.

Obesity has been quite a hot topic since the release of the new body mass index (BMI) guidelines in June (1998). We have fielded many calls from people wanting to know more about our research. What are our thoughts on obesity and the BMI?

Numerous studies show that obese people have higher rates of cardiovascular disease, diabetes, osteoarthritis of the knee, gall bladder disease and some cancers than normal weight people. Indeed many physically people are thinner than unfit people. But how do we know that higher disease or death rates in obese people are due to the obesity and not the inactivity and low fitness levels that often cause obesity?

Research that we've conducted at The Cooper Institute suggests that fitness, not fatness, is the more important issue. We've come to this conclusion after evaluating the relationship of cardiorespiratory fitness to mortality in men grouped by body mass index (BMI).

The Aerobics Center Longitudinal Study (ACLS) is an ongoing study that involves patients examined at the Cooper Clinic in Dallas from 1970 to 1989. It comprises 25, 389 men from the date of their examination to the date of their death or until December 31, 1989.

On joining the study, the participants were examined and measured for height and weight. They completed a demographic and lifestyle questionnaire, and took a maximal exercise test on a treadmill. Each man was assigned a fitness category based on his treadmill test performance. The least fit 20% were classified as "low fit," the next 40% as "highly fit." They were also grouped into BMI categories of less than 27, 27-30 or greater than 30.

The research showed that death rates were similar for moderate and highly fit men in all BMI categories, and death rates for men with low fitness levels were higher regardless of their BMI category. (Women were not included in this study due to a limited sample size; however, we would expect to see similar results.)

Fitness was a more powerful predictor of mortality than BMI. In fact, we found that low-fit men with a BMI of less than 27 were at a greater risk for death than high -fit men with a BMI of greater than 30. (See "Physical Fitness, Mortality and Obesity." International Journal of Obesity, 1995, Suppl. 4, S41-44.)

Based on additional research, we determined that the percentage of a person's body weight derived from fat does not seem to matter in predicting all-cause mortality after cardiorespiratory fitness is taken into account.

Nor does waist girth. When the ACLS study measured 14,000 of these men for waist girth, it was found that fit men with big waists had a much lower death rate than unfit men with small waists. Making adjustments in the analysis for smoking, high blood pressure and cholesterol didn't alter the results.

As a result of our findings, we believe that no matter how you split up the population, fitness has a strong inverse relationship with mortality.

The good news is that to be moderately or highly fit, you don't have to be an athlete, although you do need to be physically active on a regular basis. However increasing your fitness can make an important difference to your health. The men in the Aerobics Center Longitudinal Study who improved from low fitness to moderate or high fitness levels cut their mortality rate in half compared with those who stayed unfit. Those who improved from moderate to high fitness decreased their mortality rate by 12% to 15%. (See "Changes in Physical Fitness and All-Cause Mortality," JAMA, April 12, 1995, Vol.273, No. 14)

The way to become physically fit is to become active. Doing 30 minutes of moderate physical activity a day is enough to put people into the moderate fitness category. Thinness is fine if you want to be a swimsuit model. But, as our research shows, you are better off being fit and having a fat waist than having a small waist and being unfit.

Steven Blair, P.E.D., is director of research at The Cooper Institute for Aerobics Research. He also serves as president for the National Coalition for Promoting Physical Activity. You can visit them online at www.cooperinst.org to discover more about their research, educational opportunities and products. The Cooper Institute for Aerobics Research is located at 12330 Preston Road, Dallas, TX 75320, phone: (972) 341-3200, fax: (972) 341-3224.