Your body burns calories all the time, even while you're sitting on your duff reading this column. So to measure the true effect of a workout, you take the number of calories you burned while exercising and subtract those calories your body would have used anyway during that time.
When the men walked their miles in 19 minutes at Syracuse, researchers found that they only burned 52 more calories than they would have had they been sitting on the couch during this time. On the other hand, the runners burned 105 net calories — twice as much — in the 9 ½ minutes it took them to run a mile.
If you look at the net effect over time, the results are even more pronounced. Walking for one hour burns 165 net calories, while running at just under 10 minutes per mile for this time uses four times as much energy: 660 net calories.
Please don't take this as an anti-walking message. Walking is good exercise, and it can help improve cardiovascular health. But if you're able to run, it burns far more calories.
Walking can still be an effective tool for weight control. You may just have to walk a little more (or faster or at an incline on a treadmill) to meet your goals.
Prescott, a physician and medical researcher, is president of the Oklahoma Medical Research Foundation. Cohen is a marathoner and OMRF's senior vice president and general counsel.