The Cooper Institute
 

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

 
 

Cardiorespiratory Fitness Level Strongly Impacts Mortality Risk in Men and Women: The Cooper Center Longitudinal Study

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Monday, Apr 02, 2018

In a previous blog, we introduced you to the Cooper Center Longitudinal Study (CCLS),  the oldest and largest study of its kind in the world. Briefly, patients who receive a comprehensive preventive exam at Cooper Clinic are followed for morbidity (illness or injury) and mortality (death) over time. The overarching issue that we address in the CCLS is how patients’ characteristics, health habits and cardiorespiratory fitness (CRF) level impact the risk of future health outcomes. During the Cooper Clinic exam, CRF is objectively measured via a maximal treadmill exercise test.

To date, nearly 240,000 treadmill tests have been administered by the Clinic; this comprises the world’s largest CRF database!   

In 1989, Cooper Institute and Cooper Clinic researchers published what is considered the landmark CCLS paper. Published in the Journal of the American Medical Association, this study reported on 13,344 Cooper Clinic men and women with an average age of 45 years who were placed into one of five groups (quintiles) based on their treadmill exercise test, age, and sex.

Quintile 1 represents low CRF, while Quintiles 2-3 and 4-5 represent moderate and high CRF, respectively. Patients were then tracked for just over 8 years following their exam. There were 283 all-cause deaths during the follow-up period. A strong inverse relationship between baseline CRF and risk of death was found during follow-up.


In other words, men and women who were moderately-to-highly fit at baseline were substantially less likely to die during follow-up when compared to men and women who were low fit.

It may interest you to know that  factors such as age and smoking that might have ‘muddied the waters’ were carefully taken into consideration during the analyses.

See Figure 1 for a graphical representation of the results. As shown in the Figure, the greatest reduction in risk* was seen when comparing the lowest fit group (quintile 1) with the next lowest fit group (quintile 2). So, if we could simply get the very low fit people in quintile 1 to become a bit more physically active, this would likely nudge them up to quintile 2. As a result, many premature deaths might be prevented (or at least delayed). While most of us take it for granted that being fit is good for us, this was the first study to definitively prove that CRF is a significant and independent predictor of all-cause mortality!

You may be wondering what it takes in order to achieve a moderate level (quintiles 2-3) 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 per week. Brisk walking is a good example of moderate intensity aerobic activity. If significant weight loss or a high level of CRF (quintiles 4-5) is your goal, then the Guidelines suggest that you may need to double this to a minimum of 300 minutes each week and/or include some vigorous intensity aerobic activity. If you are just beginning your aerobic exercise program, keep in mind that it will likely take several weeks or longer to gradually build up to this level. The Guidelines also tell us that you will reap 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, as we will have several CCLS-related blogs throughout 2018!  

*Risk of death is expressed as the number of deaths per 10,000 person-years of data. Here are a couple of examples of how person-years of data are calculated: If one person is followed for one year, then we have 1 x 1 = 1 person-year of data. If 1000 people are followed for 10 years, then we have 1000 x 10 = 10,000 person-years of data.

References
Blair, S.N., Kohl, H.W., Paffenbarger, R.S., Clark, D.G., Cooper, K.H., Gibbons, L.W. (1989). Physical fitness and all-cause mortality. Journal of the American Medical Association, 262:2395-2401.

Haskell, W.L.(2007). Physical activity and public health: updated recommendation for adults. From the American College of Sports Medicine and the American Heart Association. Medicine and Science in Sports and Exercise, 39(8):1423-1434.






Note: Did you know that The Cooper Institute is one of few organizations with a nationally accredited personal training certification? If you’re interested in enhancing your health and fitness knowledge, or helping others on their path to wellness, visit http://www.cooperinstitute.org/certified-personal-trainer today!