This is the first of a series of eight installments related to physical fitness entitled: Think of Exercise as a Pill that Promotes Long Life and a Whole Lot More. New entries on this topic will appear weekly for next eight weeks.
I’d like to make a point that may impress you. Think for a minute about the multitude of chronic diseases and the wonderful drugs that have been developed for them. When a drug company discovers a new drug that promises to cut flare-ups of a chronic disease by 30 percent, this is considered a drug worth pursuing, worth investing hundreds upon hundreds of millions of dollars to bring to market. Drugs don’t have to stamp out symptoms in 100 percent of sufferers to generate big profits. A 30 percent drop in the likelihood of suffering worsening disease draws rapt attention in the drug world.
Well, the risk of dying from any cause (“all-cause mortality”) among people who exercise regularly is also cut by 30 percent, actually more like 20-40 percent in most studies and by 50 percent in a few. In other words, free and simple exercise is just as potent, and sometimes more potent, than are many of these expensive medications.
Please understand that control of chronic diseases and prevention of death are two different things, so I’m not advocating you substitute exercise for any medications you may need. What I am saying is that if drug companies could bottle regular exercise, they’d be all over it, their television ads would be incessant, and they’d charge big bucks for it!
The studies that have demonstrated the potency of exercise are observational studies where researchers take groups of people (some who exercise a lot, some who exercise a little, and some who exercise not at all) and follow them over time. These studies go on for anywhere from 5 to 25 years and during that time, the researchers observe to see how many study subjects die, how many have strokes or heart attacks, how many get diabetes, how many get cancer, etc.
Observational studies are not as definitive as randomized, controlled trials; observational studies cannot prove that one thing causes another. Well-done randomized, controlled trials have the power to prove causation but observational studies do not; they can only observe that people who exercise regularly live longer. However, the observational data for exercise is so consistent over so many studies that it’s highly likely exercise plays a major role in preventing death.
 Kodama S, Saito K, Tanaka S, et al. Cardiorespiratory Fitness as a Quantitative Predictor of All-Cause Mortality and Cardiovascular Events in Healthy Men and Women. JAMA (Journal of the American Medical Association) 2009; 301:2024.