Tomorrow is Tuesday, I’ll spend five minutes warming up on the Versa-Climber. Then I’ll do 30 minutes on a stair mill. On Wednesday a personal trainer will work me like a farm animal for an hour. Thursday is “body wedge” class, which involves another exercise contraption (device). Friday will bring a 5.5-mile run, the extra half-mile my exhausting compensation of any gastrono mical (the art or science of good eating) indulgences during the week.　　I have exercised like this—obsessively, a bit persistently—for years, but recently I began to wonder: Why am I doing this? Except for a two-year period at the end of an unhappy relationship—a period when I self-medicated with lots of Italian desserts—I have never been overweight. One of the most widely accepted, commonly repeated assumptions in our culture is that if you exercise, you will lose weight. But I exercise all the time, and since I ended that relationship and cut most of those desserts, my weight has returned to the same 163 lb. it has been most of my adult life. I still have gut fat that hangs over my belt when I sit. Why isn’t all the exercise wiping it out?　　(1)________________. Of course, some people join and never go. Still, as one major study— the Minnesota Heart Survey-found, more of us at least say we exercise regularly. The survey ran from 1980, when only 47％of respondents said they engaged in regular exercise, to 2000, when the figure had grown to 57％.　　(2) ________________. Yes, it’s entirely possible that those of us who regularly go to the gym would weigh even more if we exercised less. But like many other people, I get hungry after I exercise, so I often eat more on the days I work out than on the days I don’t. Could exercise actually be keeping me from losing weight?　　(3) ________________. Today doctors encourage even their oldest patients to exercise, which is sound advice for many reasons: People who regularly exercise are at significantly lower risk for all manner of diseases—those of the heart in particular. They less often develop cancer, diabetes and many other ill-nesses. But the past few years of obesity research show that the role of exercise in weight loss has been wildly overstated.　　(4) ________________. Many recent studies have found that exercise isn’t as important in holding 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.　　(5) ________________. That causes us to eat more, which in turn can cancel out 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.　　(本文选自Time 2009年刊)　　[A] And yet obesity figures have risen dramatically in the same period: a third of Americans are obese, and another third count as overweight by the Federal Government’s definition.　　[B] The conventional wisdom that exercise is essential for shedding pounds is actually fairly new. As recently as the 1960s, doctors routinely advised against rigorous exercise, particularly for older adults who could injure themselves.　　[C] It’s a question many of us could ask. More than 45 million Americans now belong to a health club, up from 23 million in 1993. We spend some $19 billion a year on gym memberships.　　[D] The findings were surprising. On average, the women in all the groups, even the control group, lost weight, but the women who exercised—sweating it out with a trainer several days a week for six months—did not lose significantly more weight than the control subjects did.　　[E] 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.　　[F] “In general, for weight loss, exercise is pretty useless,” says Eric Ravussin, chair in diabetes and metabolism (any basic process of organic functioning or operating) at Louisiana State University and a prominent exercise researcher.　　[G] Yes, although the muscle-fat relationship is often misunderstood. According to calculations published in the journalObesity Researchby a Columbia University team in 2001, a pound of muscle bums approximately six calories a day in a resting body, compared with the two calories that a pound of fat burns.