The Cooper Institute

Founded in 1970 by the "Father of Aerobics"
Kenneth H. Cooper MD, MPH


Introduction to the Cooper Center Longitudinal Study (CCLS)

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Live well

Friday, Feb 02, 2018

The Cooper Center Longitudinal Study (CCLS): the Largest Study of its’ Kind!

Prior to establishing Cooper Clinic and The Cooper Institute nearly 50 years ago, Dr. Kenneth Cooper knew that regular aerobic exercise was a key component for maintaining a high quality of life. However, the scientific data necessary to support this notion was sparse at the time.

When he first began seeing patients in the Clinic, Dr. Cooper had the foresight to keep meticulous records on each of them; his thought was that this information might help to someday predict future health outcomes among these individuals.

Thus, the Cooper Center Longitudinal Study (CCLS) was born, and continues to the present day. A simple way to think of a longitudinal study is one where you thoroughly evaluate a group of patients at baseline, then follow them over time for morbidity (illness) and mortality (death) events. What you are trying to determine in such a study is how well their baseline health information predicts future morbidity and mortality.      
A key component of the comprehensive preventive exam offered by Cooper Clinic is a maximal treadmill exercise test; which provides an excellent objective measurement of cardiorespiratory fitness (CRF). You can think of CRF as the ability of the body to utilize oxygen at the cellular level. In fact, that’s what the word ‘aerobic’ means!

If you’ve never had a treadmill exercise test at Cooper Clinic, it goes like this:

  • During the first minute, the speed is 3.3 mph and there is a 0% grade. 
  • At 1 minute, the speed remains at 3.3 mph and the grade is increased to 2%.
  • Thereafter, the speed remains the same and the grade increases by 1% each minute.
  • At 25 minutes, the Clinic treadmills can’t get any steeper, so guess what happens if you aren’t fatigued yet? The speed is increased by 0.2 mph at that point and at each minute thereafter until the patient can no longer continue.
  • And just in case you are wondering, patients are not allowed to grasp the front handrail of the treadmill, because allowing them to do so would significantly overestimate their CRF level.   

Regardless of how high the CRF level of a patient is, there will come a time during the treadmill test when they become completely fatigued and need to slow down and walk on a level. In other words, the treadmill always wins! To date, approximately 260,000 treadmill tests have been administered to 115,000 patients; giving Cooper Clinic the world’s largest CRF database. Patients are compared to others of their same sex and age group and then placed into CRF categories ranging from Very Poor to Superior. It’s very important to note that in addition to CRF level, the treadmill exercise test provides additional valuable patient information. Before, during, and following the test, heart rate, blood pressure and electrocardiogram are carefully monitored to check for any abnormalities.   

So What’s Done With all of This Patient Data?

I’m so glad that you asked! With patient consent and using strict security measures to protect confidentiality, all of the patient data is sent to The Cooper Institute (CI) for analysis. Group data, rather than individual data are then examined by CI Research staff. Among the important questions that we continue to ask and answer is “How do baseline CRF and health habits relate to future serious health outcomes such as cardiovascular disease, cancer, type 2 diabetes, dementia, Medicare costs, etc.?”  Below, we will highlight the first major CCLS study. In future blogs, we will highlight other key CCLS studies. 

In 1976, Dr. Cooper published a very novel paper in the Journal of the American Medical Association that examined the association between CRF and coronary heart disease risk factors in a group of 3000 men with an average age of 45 years. He found a strong inverse relationship between CRF and levels of resting heart rate and blood pressure, blood cholesterol, glucose, and triglyceride level, body weight, and percent body fat. In other words, men with higher levels of CRF had more favorable values for these important risk factors than men with lower levels of CRF. While this finding may seem somewhat intuitive today, his was actually the first published study to demonstrate a beneficial association between CRF and coronary risk factors! As a bonus, levels of lung function were more favorable across increasing levels of CRF as well. This key paper by Dr. Cooper helped to set the stage for hundreds of future CCLS papers.

If you are sedentary and have a low level of CRF, you may be wondering what it takes in order to achieve a moderate level of CRF. Meeting the current public health guidelines for physical activity should help ensure that this goal is met. The Guidelines call for accumulating a minimum of 150 minutes of moderate intensity aerobic activity (e.g., brisk walking) per week. If you are just beginning your aerobic exercise program, keep in mind that it may take several weeks to gradually build up to this level. The Guidelines also tell us that you will reap many additional health benefits if you can add at least 2 days a week of resistance training to your workout routine.   

For additional information regarding the CCLS, check The Cooper Institute website frequently.


Cooper, K.H., Pollock, M.L., Martin, R.P., White, S.R., Linnerud, A.C., Jackson, A. (1976). Physical fitness level versus selected coronary risk factors.  JAMA, 236:166-169.
Haskell, W.L. Physical activity and public health: updated recommendation for adults

From the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc, 2007. 39(8):1423-1434.