DOES RUNNING INCREASE LONGEVITY?
A google search of “running and longevity” produces dozens of interesting and encouraging articles. There were a few that I found most notable. One study, for example, from Australia followed 230,000 people for up to 35 years to see how many survived. During the study, 26,000 individuals died, and it was determined that the runners in the original group had a 27% lower death rate. The runners also had a 30% lower risk of death from heart disease and 23% lower risk of cancer death. Any amount of running, even five miles a week, provided these results.
Another study lasted 15 years and had 55,000 individuals, 14,000 of which were runners. This study concluded that runners had a 90% less chance of dying of cardiovascular disease than the non-runners during the study period. It also found the benefits plateaued at 20 miles per week.
A third study was reported in the New York Times, and it received much attention when it concluded that one hour of running increased longevity by seven hours. That 700% return sound incredible. My 40 years of running at 40 miles per week would, according to this, give me 405 extra days to live. A study at the Cleveland Clinic compared elite runners to non-elite runners and followed the 122,007 individuals 22 years. A big part of this study was testing on the treadmill for aerobic fitness. The elite group, of course, had the highest aerobic fitness, and they had an 80% reduction in mortality. The conclusion was that the higher the aerobic fitness, the better the longevity. This is especially true for older individuals.
These studies and all similar ones suffer from one major difficulty. Simply because running, or any other aerobic exercise, is associated with longevity does not prove that it actually causes it. Association is not the same as causality. It has been shown that individuals who are already in fairly good health to begin with are more likely to be drawn to running than those who are in poor or marginal health. It is also true that dedicated runners often have lifestyle habits that are conducive to health and longevity. They tend to eat well, maintain a low weight, get adequate sleep and avoid overindulgence in drugs, alcohol, and smoking.
Running certainly increases aerobic fitness, and this is one of the best indicators of an individual’s long-term health. Aerobic fitness is something an individual has control over and can choose to improve it or let it decline. Heart disease is the number one cause of death around the world and improved aerobic fitness would certainly have an impact on reducing the risk. Running tends to speed up movement through the digestive tract. This is beneficial since we take in trace amounts of toxic substances with our food, and the shorter amount of time they spend in the colon, the less likely they and to be absorbed and possibly lead to cancer.
The bottom line is that it is difficult or impossible to prove that running directly increases longevity, but it is clearly associated with longevity, as long as all the other factors are present as well.