Run, don't walk

Consider the various health and fitness “truisms” that have turned out to be not so true. As in false.Eggs are high cholesterol bombs. Avoid them. Uh, no.Butter is artery-clogging junk. Change to margarine. Nope.No pain; no gain. So wrong.Twenty minutes of exercise three times a week is all you need. Sorry, no.Walking is as good for you as running. Apparently not. This is the latest bit of dogma to bite the dust.It turns out that running may reverse aging in ways that walking does not, according to a new study of active older people. It was a small study -- 30 men and women in their mid- to late-60s or early 70s – conducted at the University of Colorado’s Locomotion Laboratory. (Interesting to note here that Colorado always ranks as the #1 healthiest state in the union. Apparently, the researchers had no trouble whatsoeverrecruiting healthy, active volunteers.) For the study period, 15 of these volunteers walked at least three times a week for 30 minutes or more. The other 15 ran (gentle jogging speed) at least three times a week for 30 minutes or more. Then the scientists had each runner and each walker complete three brief walking sessions on specially equipped treadmills that measured the way they moved. The volunteers also wore masks to measure oxygen intake, which helped the scientists determine cardiovascular efficiency.The results? The runners won. By a lot. They required considerably less energy to move at the same pace as the walkers. In fact, when the researchers compared the walking efficiency of the older runners to that of young people (measured in earlier experiments at the same lab), they found that 70-year-old runners had about the same walking efficiency as a typical sedentary college student. The older walkers, on the other hand, had about the same walking economy as people of their own age who were sedentary.Yikes.No one disputes that walking is excellent exercise. All kinds of studies have concluded that older people who walk have significantly lower rates of obesity, arthritis, heart disease and diabetes. But researchers have noted that the walking ability (strength, endurance, efficiency) of walkers decreases with age. They move slower, fatigue more easily, etc. So it was thought that physical decline was a consequence of age, they thought.The older runners in this study disproved that.How did they stay so fit – as fit as nonexercisers 40 years their junior? One word: mitochondria. I wrote about these powerhouses within our cells in my book, Counterclockwise. I even had my own mitochondria measured. So the conclusion of the Colorado researchers will sound familiar to my readers: Intense, prolonged aerobic exercise (like running) increases the number and activity and efficiency of mitochondria in the muscles. More mitochondria mean more energy with less effort. More mitochondria mean a higher level of fitness. More mitochondria move us counterclockwise.Yes, running is tough on joints. And it’s not for everyone. The take-home message is here is that intensity of effort can make a very big difference in cardiovascular health and muscle efficiency. The take-home message is that it is NOT age that accounts for lack of fitness; it is lack of strenuous exercise.