|"Only dull people are brilliant at breakfast"
|"The liberal soul shall be made fat, and he that watereth, shall be watered also himself."
-- Proverbs 11:25
"In general, for weight loss, exercise is pretty useless," says Eric Ravussin, chair in diabetes and metabolism at Louisiana State University and a prominent exercise researcher. Many recent studies have found that exercise isn't as important in helping people lose weight as you hear so regularly in gym advertisements or on shows like The Biggest Loser — or, for that matter, from magazines like this one.
The basic problem is that while it's true that exercise burns calories and that you must burn calories to lose weight, exercise has another effect: it can stimulate hunger. That causes us to eat more, which in turn can negate the weight-loss benefits we just accrued. Exercise, in other words, isn't necessarily helping us lose weight. It may even be making it harder.
Last year the International Journal of Obesity published a paper by Gortmaker and Kendrin Sonneville of Children's Hospital Boston noting that "there is a widespread assumption that increasing activity will result in a net reduction in any energy gap" — energy gap being the term scientists use for the difference between the number of calories you use and the number you consume. But Gortmaker and Sonneville found in their 18-month study of 538 students that when kids start to exercise, they end up eating more — not just a little more, but an average of 100 calories more than they had just burned.
If evolution didn't program us to lose weight through exercise, what did it program us to do? Doesn't exercise do anything?
Sure. It does plenty. In addition to enhancing heart health and helping prevent disease, exercise improves your mental health and cognitive ability. A study published in June in the journal Neurology found that older people who exercise at least once a week are 30% more likely to maintain cognitive function than those who exercise less. Another study, released by the University of Alberta a few weeks ago, found that people with chronic back pain who exercise four days a week have 36% less disability than those who exercise only two or three days a week.
But there's some confusion about whether it is exercise — sweaty, exhausting, hunger-producing bursts of activity done exclusively to benefit our health — that leads to all these benefits or something far simpler: regularly moving during our waking hours. We all need to move more — the Centers for Disease Control and Prevention says our leisure-time physical activity (including things like golfing, gardening and walking) has decreased since the late 1980s, right around the time the gym boom really exploded. But do we need to stress our bodies at the gym?