Doctors and lots of people on treadmills in health clubs believe better “cardio” leads to a longer life. People run, swim, row, climb and engage in all sorts of cardiorespiratory fitness activities in order to keep the Grim Reaper away a little longer. The big question is “does it work?”
Researchers at the Cleveland Clinic may have answered that question. If you love cardio exercise, you may love their answer. If not, you may want to learn to like it if you want to live longer.
The Cleveland Clinic team used a retrospective study of over 122,000 patients who engaged in exercise testing on treadmills in the Clinic between January 1, 1991 and December 31, 2014. They were measuring all-cause mortality in relation to the benefits of exercise and overall fitness.
Their paper, published in the Journal of the American Medical Association Network Open, claims that not only does cardio fitness lead to longer life, there may be no limit to the benefits of aerobic fitness!
Extreme aerobic fitness was linked to the greatest benefits in reduction of long-term mortality risk. This effect was especially notable in patients 70 and older and those who suffered with hypertension. The paper also noted that all patients who improved cardiorespiratory fitness saw a reduction in long-term mortality from all causes.
“Aerobic fitness is something that most patients can control. And we found in our study there is no limit to how much exercise is too much,” said Wael Jaber, M.D., Cleveland Clinic cardiologist and senior author of the study. “Everyone should be encouraged to achieve and maintain high fitness levels.”
Traditionally, risk factors like smoking, diabetes and cardiovascular disease are thought of as key indicators of mortality risk. This study found that poor cardiorespiratory fitness ranked right up there with all of those.
While some recent studies have indicated a link between extreme exercise and specific adverse cardiovascular outcomes like coronary artery disease and atrial fibrillation, this study seems to contradict those. In this study, extreme cardiorespiratory fitness had a positive correlation to additional survival benefits, when compared to more moderate levels of fitness.
In fact, extremely fit patients seemed to live the longest, even when other health factors were considered.
“We were particularly interested in the relationship between extremely high fitness and mortality” said Kyle Mandsager, M.D., an electrophysiology fellow at Cleveland Clinic and the lead author of the study. “This relationship has never been looked at using objectively measured fitness, and on such a large scale.”
The research team broke the subjects up into five performance groups. These were elite, high, above average, below average and low. Each study subject had previously had a stress test at the Cleveland Clinic. Those in the elite group were described as having aerobic fitness levels in the top two and a half percent by gender and age. Their fitness levels were comparable to endurance athletes. When assessing long-term survival, adjustments were made for height, weight, age and BMI as well as medications taken and comorbidities.
While there seemed to be no statistical difference in outcomes between high and elite performers in younger groups, in those over 70 years of age, things were different. In that group, elite performers showed a nearly 30 percent lower risk of mortality when compared to high performers.
Elite performers also fared best when the subgroups were analyzed by comorbidities. Generally, all-cause mortality showed an inverse relationship to cardiorespiratory fitness. Elite performers with hypertension showed a nearly 30 percent reduction in all-cause mortality risk when compared to high performers. This was the only comorbidity for which there was a statistical difference between elite and high performers.
While this study certainly points clearly to the benefits of high levels of cardiorespiratory fitness, it isn’t necessarily a call to go out an take up ultra-marathons or other extreme fitness regimens. As in all cases, if you want to start a fitness or exercise program, you would be wise to consult your physician or healthcare provider first.
After that, if you get the all-clear, it may be time to get to work on improving that cardio fitness. After all, it can apparently lengthen your lifespan!
Keep the faith and keep after it!
Journal Reference – Kyle Mandsager, Serge Harb, Paul Cremer, Dermot Phelan, Steven E. Nissen, Wael Jaber. Association of Cardiorespiratory Fitness With Long-term Mortality Among Adults Undergoing Exercise Treadmill Testing. JAMA Network Open, 2018; 1 (6): e183605 DOI: 10.1001/jamanetworkopen.2018.3605