We have extolled the virtues of exercise on many more than one occasion in this column — this must make the sixth time, I think. A report in the Journal Circulation further affirms the benefits of exercise. (1) These authors, in an observational study of over a half of a million individuals followed for more than six years from the United Kingdom’s Biobank, examined the cardiorespiratory fitness and the incidence of cardiovascular events and all-cause death. They showed that exercise cut by half the incidence of that bad stuff, even in people who had high genetic risk.
We seem to have gotten the message. We are exercising more than ever before, but a new report from the National Center for Health Statistics says physical activity and obesity rates are moving up in parallel. (2) So it doesn’t seem to make any difference in the obesity epidemic. Exercise guru naysayers Timothy Church and Corby Martin, for example, say that while we are apparently exercising more, we are sitting around and exercising less during the parts of our daily working and non-working lives that come between exercise bouts.
Indeed, a recent study report from the journal Diabetes in rats (4,5) found evidence for that kind of adjustment — the weight loss effects of voluntary exercise were countered by a reduction in nonexercise activity. Rats who ran in their running wheels moved slower between running times compared to rats who’s running wheels were locked.
So the benefits for weight loss might still exist if we only stayed more active all the time. Everybody knows that kids like to run around and older humans get tired just watching them. It has been shown that in the wild rats who have been provided running wheels placed in the woods and monitored by cameras spontaneously use them.
But the health benefits seem to accrue even though we’re not losing weight. A better explanation to connect these dots is that exercise, even the way adults have to do it, is good for your health but useless for weight loss.
The study of the health benefits of exercise mentioned at the outset, as are most studies of this issue, is observational. It could be that people who are predisposed to exercise are different in other ways and exercise would not help people who don’t do it. That cause-and-effect connundrum is the problem with all observational studies. Not eating is also good for your health and exercise is dangerous, painful and expensive. But to my mind, it’s way easier than hunger. Just an opinion. But the exercise epidemic is evidence, I think, for that opinion being more widespread than weight loss by dieting.
Just do it, like the Nike commercials say.
1. Tikkanen E, Gustafsson S, Ingelsson E. Associations of Fitness, Physical Activity, Strength, and Genetic Risk With Cardiovascular Disease: Longitudinal Analyses in the UK Biobank Study https://doi.org/10.1161/CIRCULATIONAHA.117.032432. Circulation. 2018;CIRCULATIONAHA.117.032432. Originally published April 9, 2018
3. Church T, Martin CK. The Obesity Epidemic: A Consequence of Reduced Energy Expenditure and the Uncoupling of Energy Intake? First published: 20 December 2017 https://doi.org/10.1002/oby.22072
4. Lark DS et al. Reduced Nonexercise Activity Attenuates Negative Energy Balance in Mice Engaged in Voluntary Exercise. Diabetes 2018 Mar; db171293. https://doi.org/10.2337/db17-1293
John DiTraglia, M.D., is a pediatrician in Portsmouth. He can be reached by email at firstname.lastname@example.org or call 740-354-6605.