Posted on: Thursday, September 16, 2004
Better fit and fat than thin and unfit
By Susan Morse
Washington Post
Fit or fat? What's it gonna be? We all know the answer to that one.
But what if the question's a little tougher: If you could pick only one, would you choose to be fit but fat? (Yes, those people exist. I can't be the only one out there who's sometimes made the dumb pre-gym-class mistake of sizing up a blocky fitness instructor as a pushover.) Or would you rather be thin but not physically fit?
That's not an idle question. Researchers, it turns out, have been puzzling over the matter for years, anxious to know which to emphasize — diet or exercise? — in the quest to stay healthy.
On the surface, at least, two studies that made headlines last week made the answer look like a toss-up.
One study, in the Journal of the American Medical Association, suggested that women's physical fitness level was a much better predictor than body weight of the risk of heart disease. (Translation: Fitness rules. Particularly when this study is viewed along with a previous one that found poor fitness in women poses a greater risk of death than it does in men.)
But the other study, also in JAMA, found that a woman's body mass index, or BMI — a common measure of weight relative to height — was a far better predictor than fitness level of her risk of contracting diabetes. (Translation: Hey, wait a minute. Didn't you just say ... )
So where does that leave you and me? With two conclusions, we submit:
If on the other hand you were to pursue a healthy BMI without exercising, there would be no certain benefit to your fitness.
That's not just our opinion. There's good evidence.
Brian Sharkey, former president of the American College of Sports Medicine, cites some of it in his tome "Fitness & Health" (Human Kinetics, 1979), now in its fifth edition.
When women in two studies used diet, exercise or a combination of both to lose weight, all succeeded. But the women who exercised lost more fat, conserved more lean tissue and maintained their metabolic rate at a level needed to burn calories.
Those who relied on diet alone, by contrast, typically experienced a 10 percent to 15 percent drop in metabolic rate that made it hard to keep the weight off. Just two weeks of exercise, Sharkey said, restored the metabolic rate to its pre-diet level.
When you engage in moderate exercise (such as walking, jogging or cycling) 30 minutes or more per day at least five days a week, as recommended for women by the Centers for Disease Control and Prevention, you boost your calorie burning not only during those 30 minutes, but for another half hour or more after you stop. Add weight training a few times a week to maintain or increase lean muscle tissue, and you can rev up the system a bit further, burning perhaps 30 or 40 calories a day more.
Among some of the other benefits are more strength, flexibility, and energy to do the things you like to do, a more positive mental outlook and better overall health.
But you didn't need any fancy medical research to tell you that.
