Exercise has been shown to be ineffective when it comes to losing weight – your diet is the key.
... More and more research in both the UK and the US is emerging to show that exercise has a negligible impact on weight loss. That tri-weekly commitment to aerobics class? Almost worthless, as far as fitting into your bikini is concerned. The Mayo Clinic, a not-for-profit medical research establishment in the US, reports that, in general, studies "have demonstrated no or modest weight loss with exercise alone" and that "an exercise regimen… is unlikely to result in short-term weight loss beyond what is achieved with dietary change."
There's another, more insidious, problem with pinning all your hopes for a holiday bod on exercise. In what has become a defining experiment at the University of Louisiana, led by Dr Timothy Church, hundreds of overweight women were put on exercise regimes for a six-month period. Some worked out for 72 minutes each week, some for 136 minutes, and some for 194. A fourth group kept to their normal daily routine with no additional exercise.
Against all the laws of natural justice, at the end of the study, there was no significant difference in weight loss between those who had exercised – some of them for several days a week – and those who hadn't. (Church doesn't record whether he told the women who he'd had training for three and half hours a week, or whether he was wearing protective clothing when he did.) Some of the women even gained weight.
Calorie Compensation
Church identified the problem and called it "compensation": those who exercised cancelled out the calories they had burned by eating more, generally as a form of self-reward.
- The post-workout pastry to celebrate a job well done – or even a few pieces of fruit to satisfy their stimulated appetites – undid their good work.
- In some cases, they were less physically active in their daily life as well.
- the pair showed that when the children in their experiment exercised, they ended up eating more than the calories they had just burned, sometimes 10 or 20 times as many.
- "Although physical activity is thought of as an energy-deficit activity," they wrote, "our estimates do not support this hypothesis."...
Terry Wilkin, professor of endocrinology and metabolism at the Peninsula Medical School in Plymouth, argues that we have. The title of his latest research is: "Fatness leads to inactivity, but inactivity does not lead to fatness". Wilkin is nearing the end of an 11-year study on obesity in children, which has been monitoring the health, weight and activity levels of 300 subjects since the age of five.
When his team compared the more naturally active children with the less active ones, they were surprised to discover absolutely no difference in their body fat or body mass.
That's not to say that exercise is not making the children healthy in other ways, says Wilkin, just that it's having no palpable effect on their overall size and shape. "And that's a fundamental issue," he adds, "because governments, including ours, use body mass as an outcome measure." In other words, obesity figures are not going to improve through government-sponsored programmes that focus primarily on exercise while ignoring the behemoth of a food industry that is free to push high-calorie junk to kids (and, for that matter, adults).
A Second Form of Compensation
For one thing, Wilkin believes he has discovered another form of "compensation", similar to Timothy Church's discovery that we reward ourselves with food when we exercise. Looking at the question of whether it was possible to change a child's physical activity, Wilkin's team put accelerometers on children at schools with very different PE schedules: one which offered 1.7 hours a week, and another that offered nine hours.
- "The children did 64% more PE at the second school.
- But when they got home they did the reverse.
- Those who had had the activity during the day flopped and those who hadn't perked up, and if you added the in-school and out-of-school together you got the same.
- From which we concluded that physical activity is controlled by the brain, not by the environment – if you're given a big opportunity to exercise at one time of day you'll compensate at another."
The good news
The latest scientific findings from the US suggest that an intense workout in the gym is actually less effective than gentle exercise in terms of weight loss. Barry Braun, associate professor of kinesiology at the University of Massachusetts, says that the evidence emerging from his research team shows that moderate exercise such as "low-intensity ambulation" (ie walking) may help to burn calories "without triggering a caloric compensation effect" – ie without making you reach for a snack the moment you're done. In one experiment, Braun showed that simply standing up instead of sitting used up hundreds more calories a day without increasing appetite hormones in your blood. ...
Full story from Emma John, the deputy editor of the Observer Magazine. Reprinted in The Guardian.
