Living With

Exercise and Inflammation

David Mendosa Health Guide July 19, 2007
  • We know that exercise somehow reduces our risk of heart disease, the most common complication of diabetes. But we really haven’t known how.

    Now for the first time a new study offers an explanation of how it works.

    The study, “Aerobic Exercise Attenuates Inductible TNF Production in Humans” will appear in a forthcoming issue of The Journal of Applied Physiology. The lead author, Richard Sloan, professor of behavioral medicine at the Columbia University Medical Center, kindly sent me a pre-print of the article. Just the abstract is available online.

    That’s a terribly technical title. Exercise done with oxygen – referring to the use of oxygen in a muscle’s energy-generating process – is aerobic. Many types of exercise are aerobic. Generally, we do aerobic exercise at a low to moderate level of intensity for quite a while. For example, when we run at a moderate pace it is aerobic, but sprinting isn’t.

    But in this study Dr. Sloan and his associates study how two different levels of aerobic exercise affected a group of 61 young adults, who just happened to be students at Columbia University. These students worked out on a stationary bicycle, treadmill, step machine, or an elliptical step machine.

    The researchers found that a high exercise level – but not a moderate one – decreased the production of tumor necrosis factor (TNF), which is an inflammatory protein. A high level, they say, was building up to 75 to 80 percent of their maximum heart rate. The control group worked out for the whole 12-week program at 55 to 60 percent of their maximum heart rate.

    Earlier I have written here about how to calculate your heart rate. My doctor recommended in that article that we work out at 70 to 80 percent of our maximum heart rate. Right on!

    “Our data demonstrate that a 12-week aerobic training program significantly decreases inducible TNF production in whole blood in sedentary young adults, but that this effect was seen only in the high intensity-training group,” the new study concludes. “Previous studies on the anti-inflammatory effects of exercise training have been equivocal, reflecting differences in subject selection, inflammatory markers, and training activities.”

    The study didn’t deal with my favorite form of exercise, walking or hiking. But it’s got to follow that walking faster is better for all of us, particularly those of us who have diabetes, who need exercise to get or stay fit.

    Other studies showed that most of us most of us don’t walk fast enough. I wrote about that here.

    Some researchers on the fringes of science have been arguing that diabetes is a disease of inflammation. Now we are getting evidence that they may be on the right track.

    So whether you get your exercise in the gym or in the hills, it’s better to go for it – quickly.