The Cooper Institute
 

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

 
 
 

Does Fitness Still Matter In This Age of Modern Medicine?

Posted in

Wednesday, Apr 01, 2020

Researchers at The Cooper Institute look at whether lifestyle changes and advancements in health care negate the need for fitness.


Over the last 50 years, advances in modern medicine have helped us live longer by identifying and treating risk factors for heart disease, stroke and cancer. But with these significant changes and improvements in cardiac and cancer treatment, does fitness still matter?

A new study from The Cooper Institute, along with researchers from Harvard and Stanford University, takes a look to see if these changes in disease prevention, detection and treatment have any effect on the relationship between fitness and mortality.

The Landmark Study (1989)
 

Back in 1989, researchers from The Cooper Institute published a landmark study showing a strong relationship between cardiorespiratory fitness (CRF) and all-cause mortality risk in a large sample of patients from the Cooper Center Longitudinal Study (CCLS). That study helped change the course of preventive healthcare, especially in the field of cardiology. It even prompted the American Heart Association (AHA) to add physical inactivity as a modifiable risk factor for heart disease in 1992.


Since that time, many improvements in screening, diagnosis, and treatment of disease have been made, resulting in decreased mortality rates in the U.S.

Death rates from heart disease and stroke have dropped by 67% and 77%, respectively, over the past 50 years. Much of this can be attributed to new and more effective treatments and medications for chronic diseases such as hypertension, diabetes, and high cholesterol. Advanced cardiac catheterization, surgical techniques and the use of stents has also greatly contributed to improved mortality rates, as well as lifestyle changes such as the dramatic decrease in tobacco use.

Cancer death rates have also improved in the last 30 years. The decline in tobacco use combined with more aggressive screening and sophisticated treatments also contributed to marked reductions in overall cancer mortality and a significant improvement in 5-year cancer survival rates.

However, modern medicine hasn’t saved us from poor lifestyle choices. In the past few decades, we’ve seen major increases in the rates of obesity, hypertension, metabolic syndrome, and type 2 diabetes. The question that our research team wanted to answer was whether all of these changes affect the relationship between fitness and mortality. Does fitness still matter?                                                                                                                        

The New Study (2020)
 

This study looked at nearly 48,000 men over a 50-year span who all completed baseline examinations including a maximal treadmill exercise test at the Cooper Clinic. The men were divided into two chronological groups based on changes in cardiovascular interventions that became more common in the early 1990s, including the use of statins, thrombolytic drugs and stents.


Men from both groups were categorized as low fit, moderate fit or high fit based on their treadmill test results and age group. When compared against those with low fitness, men in both groups demonstrated that high and moderate fitness significantly decreases all-cause mortality risk:

  • Heart disease and cancer combined accounted for 70% and 63% of all deaths in groups 1 and 2, respectively.
  • High fitness reduced mortality by 47% in the group seen between 1970 and 1991; Moderate fitness reduced mortality by 40%.
  • High fitness reduced mortality by 48% in the group seen between 1992 and 2014; Moderate fitness reduced mortality by 24%.
     

Central Illustration
 

The cardiorespiratory fitness level of each group (expressed in METs) is shown on the horizontal line of the graph (bottom side). The 10-year death rate from all causes is shown on the vertical line (left side). The blue line represents Group 1 and the dotted red line represents Group 2. On the left side where fitness levels are the lowest, we see that Group 1 has higher mortality than Group 2. As we travel across the graph, we see that mortality drops as fitness level increases. What is clear in this graph is that even though Group 2 starts with lower mortality, thanks to modern medicine, both groups see significant improvements in mortality as fitness levels increase. Fitness still matters.

“The findings emphasize how important it is for us to be physically fit – even today, when medical diagnosis and treatment have advanced so much compared with a few decades ago,” said senior author Dr. I-Min Lee, an epidemiologist in the Division of Preventive Medicine at Brigham and Women’s Hospital, Professor of Medicine at Harvard Medical School and Professor of Epidemiology at Harvard T.H. Chan School of Public Health.

The results of the 50-year combined study, published in the Journal of the American College of Cardiology, confirm and reinforce the importance of fitness even with today’s modern and aggressive screening and treatments for chronic disease. In fact, the AHA Scientific Statement recommends the inclusion of a baseline measured fitness assessment as a clinical vital sign.

What About Women?
 

At the time of the original study, the overwhelming majority of Cooper Clinic patients were men. There just weren’t enough women or related deaths in the original sample size for this type of study, so we couldn’t compare and evaluate women in the second group. However, we recently published a study looking at fitness levels of nearly 20,000 Cooper Clinic women. That study showed that women with moderate and low fitness levels were 1.9 and 2.5 times more likely to die from cardiovascular disease (CVD) than those with high fitness, respectively.

CRF Measurement and Physical Activity Guidelines
 

Because CVD is the leading cause of death in the U.S. for both men and women, all adults are strongly encouraged to follow the AHA Scientific Statement, which recommends a baseline measurement or estimate of CRF be performed. This fitness assessment can be done in a clinical setting with a maximal exercise test or in a non-clinical setting using either a running test (Cooper 1.5 mile run or 12 minute run test) or walking test (Rockport walk test). A bicycle ergometer or a non-exercise questionnaire to estimate fitness is another option, although less accurate. All adults should meet the 2018 Physical Activity Guidelines, which consist of a minimum of 150 minutes each week of moderate-intensity aerobic activity or 75 minutes each week of vigorous-intensity aerobic activity, along with at least two days of strength training each week.  

References

Blair, S.N., et al. (1989). Physical fitness and all-cause mortality. Journal of the American Medical Association. 262:2395-2401.

Farrell, S.W., et al. (2020). Relevance of fitness to mortality risk in men receiving contemporary medical care. Journal of the American College of Cardiology. Published online March 30, 2020.

Piercy, K.L., et al. (2018). The Physical Activity Guidelines for Americans. JAMA. doi:10.1001/jama.2018.14854