Wednesday, August 12, 2009

Fat Loss is Not a Matter of Exercise

I received an email yesterday from one of my certifying agencies, ACSM. An ACSM "expert" offered support for a new article from Time Magazine, titled "Why Exercise Won't Make You Thin." The article stated that ACSM agreed daily exercise "may not be necessary" for fat loss. Overall, the article by John Cloud had many interesting points, jumped around a bit, but did address a major point: Weight loss comes from nutrition changes, NOT exercise (as I have stated before here and here). Here are some of the points and quotes from the article (with direct quotes from the article in italics):
  • "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.
  • This is weak evidence due to the lack of nutritional control, but nonetheless, exercise did not make a significant change in this stated study: ...the peer-reviewed journal PLoS ONE...published a remarkable study supervised by a colleague of Ravussin's, Dr. Timothy Church, who holds the rather grand title of chair in health wisdom at LSU. Church's team randomly assigned into four groups 464 overweight women who didn't regularly exercise. Women in three of the groups were asked to work out with a personal trainer for 72 min., 136 min., and 194 min. per week, respectively, for six months. Women in the fourth cluster, the control group, were told to maintain their usual physical-activity routines...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...It's true that after six months of working out, most of the exercisers in Church's study were able to trim their waistlines slightly — by about an inch. Even so, they lost no more overall body fat than the control group did.
  • Calorie expenditure is pretty insignificant. Church referenced this by mentioning a conversation with his wife's friends, who all go running for an hour per day and are not losing weight: "What are you doing after you run? (asked Church)" It turns out one group of friends was stopping at Starbucks for muffins afterward. Says Church: "I don't think most people would appreciate that, wow, you only burned 200 or 300 calories, which you're going to neutralize with just half that muffin."
  • I am a huge supporter of avoiding the need for will power to make good food choices. How successful have you been in past attempts to avoid sweets in the house or stay dedicated to the tougher, more frequent workout routine? Cloud states: Many people assume that weight is mostly a matter of willpower — that we can learn both to exercise and to avoid muffins and Gatorade. A few of us can, but evolution did not build us to do this for very long. In 2000 the journal Psychological Bulletin published a paper by psychologists Mark Muraven and Roy Baumeister in which they observed that self-control is like a muscle: it weakens each day after you use it. If you force yourself to jog for an hour, your self-regulatory capacity is proportionately enfeebled. Rather than lunching on a salad, you'll be more likely to opt for pizza.
  • Some research has found that the obese already "exercise" more than most of the rest of us. In May, Dr. Arn Eliasson of the Walter Reed Army Medical Center reported the results of a small study that found that overweight people actually expend significantly more calories every day than people of normal weight — 3,064 vs. 2,080. He isn't the first researcher to reach this conclusion. As science writer Gary Taubes noted in his 2007 book Good Calories, Bad Calories: Fats, Carbs, and the Controversial Science of Diet and Health, "The obese tend to expend more energy than lean people of comparable height, sex, and bone structure, which means their metabolism is typically burning off more calories rather than less."
Cloud mentioned some other important points as well, a pound of added muscle uses only about six calories per day and prolonged exercise likely increases hunger.. The final conclusion Cloud arrives at is that we should try to scale down exercise but increase overall movement (walking more, taking the stairs instead of the elevator, etc.) to burn calories without increasing hunger.

Here are my main takeaways from the article:
  1. If you want to lose body fat, you must make nutritional changes. Some of my most successful fat loss clients and my own recent success has come with as little as 20 minutes of exercise a week.
  2. To eat a good diet, educate yourself and make it easy to succeed. Succeeding with the use of willpower on a daily basis is highly unlikely. Educate yourself on why you don't want to eat certain foods, why you do want to eat certain foods, and make it convenient for you to eat only good foods.

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