Does Exercise Matter for Weight Loss?

By Beachbody Nutritionist, Steve Edwards

I'm sure by now many of you have seen the recent cover of TIME magazine stating that exercise doesn't matter for weight loss. As you might imagine, we at Beachbody are a little incredulous at this premise. After all, we have files filled with thousands of individuals who've used exercise to dramatically change their bodies. Could we be the ones who are mistaken? Could all of those transformations have happened from dietary change alone? Today, let's take an analytical look at how we lose weight.

This article is going to deviate from our usual approach. As a person who has spent most of his life altering human physiques, I'm going to deconstruct the TIME article from top to bottom and try to make some sense out of what seems like a very unlikely premise. Let's begin with the tagline:

" . . . because exercise makes us hungry or because we want to reward ourselves, many people eat more—and eat more junk food, like doughnuts—after going to the gym."

Could it be true? After all, exercise not only makes you want to eat more, but it requires that your body consume more calories to recover from a breakdown of body tissue. What's unclear at this point is where the "junk food, like doughnuts" came from. My experience with Beachbody customers (and others over the last 25 years) is exactly the opposite; exercise actually leads to better eating habits because a body in tune with its needs craves healthier foods. But this is the tag line of an article that's going to circulate worldwide. Certainly, the author is about to present some compelling evidence for his argument. John Cloud proceeds to inform us:

"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."

His personal example of how exercise has not helped him lose weight seems to have left him rather bitter. "I have exercised like this—obsessively, a bit grimly—for years," he states. "But recently I began to wonder: Why am I doing this?" To me it revived memories of Gina Kolata's best-selling drivel from last year blaming the obesity epidemic on our genes, where her entire argument was based around her brother training for a marathon and losing only 3 pounds. But certainly, the cover story of TIME wasn't going to be based on one man's personal weight loss odyssey.

If only Cloud and Kolata were members of the Message Boards, we could have told them how to break plateaus using a simple periodizational approach. Of course, this may have hurt their bank accounts, but at least they'd be less disenfranchised with the fitness industry, as well as a lot healthier.

But I digress. Next, Cloud states:

"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%."

At least he used "at least say," because other studies don't back this up. In fact, numerous studies published this decade show that children exercise somewhere between 20 percent and 25 percent less than they did in the 1970s, while only eating approximately 3 percent more calories. Statistics tell us that childhood obesity rates are over 30 percent nationwide, and over 40 percent in some demographics. Obese children are 99 percent more likely to wind up as obese adults than non-obese children. In fact, we don't need statistics to tell us this at all. We just need to be observant. The absence of children playing in the streets, the empty bike racks at schools, the prevalence of video games, and the increase in things to watch on TV should make it easy to draw this conclusion sans further input. Using this background, Cloud gets down to the nitty-gritty:

"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 seems like a pretty bold statement. The physiological response by the body to exercise is to increase its metabolism. All other things being equal, this leads to weight loss, and there is no scientific evidence to rebuke it. The only scenario when it would not help is one where an individual consumed more calories than they burned off. But not only would they have to exceed the actual caloric burn of the exercise, they'd have to eat beyond the additional physiological changes the body makes to recover from exercise. And while it feels as though we're getting to the point of the article, caloric consumption in Cloud's view is always only weighed against calories burned during exercise. Furthermore, this premise dismisses the findings of at least three long-term studies done between 1997 and 2008 that show exercise is extremely important for maintaining a goal weight after weight loss.

But I'm getting ahead of myself. Cloud goes on to tell us:

"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 illnesses."

So he's advocating exercise, apparently, just not for weight loss. Odd, when two of the diseases listed above are directly related to obesity. Regardless, this dubious setup allows Cloud to drop his bomb, which is based on spotty science and conjecture:

"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."

For scientific evidence, Cloud uses a study out of Louisiana State University [LSU] that showed women on an exercise program didn't lose much more weight than a group who wasn't on an exercise program when their diets weren't monitored. Of course, the women on an exercise program still lost more weight; it just wasn't very significant. But without factoring in diet, it's hard to say what went on within this group. Surely, the dietary component of a weight loss program is important, but stating that exercise is making weight loss harder seems like a stretch, especially when citing a study where the group that exercised still lost more weight. This extrapolation was summed up well in Denis Faye's blog The Real Fitness Nerd:

"Claiming that exercise isn't effective because people use it as an excuse to otherwise misbehave is like claiming a medication isn't effective because patients don't follow the directions properly."

The conjecture continues, as Cloud continues mentioning cravings for various junk foods whenever the topic of exercise comes up. For example:

"In 2007 the American College of Sports Medicine and the American Heart Association issued new guidelines stating that 'to lose weight . . . 60 to 90 minutes of physical activity may be necessary.' That's 60 to 90 minutes on most days of the week, a level that not only is unrealistic for those of us trying to keep or find a job but also could easily produce, on the basis of Church's data, ravenous compensatory eating."

But physical activity is defined as any type of movement that increases your heart rate over time, so he's using the American College of Sports Medicine's guidelines for undefined exercise, making a jump to suggest this should happen at intensities that cause us to pig out, assuming those exist in the first place. This is in contrast to studies that show compensatory eating happens more regularly among sedentary groups. Regardless, it's virtually impossible to prove that moving our bodies more will make us "ravenous," especially when Cloud's still only referencing the LSU study.

His next leap of illogic jumps the shark:

"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."

Cloud provides no rationale for this. Maybe he would opt for pizza, as we can only assume. But no evidence is presented as to why someone would do this other than a paper published in Psychological Bulletin in 2000 that claims self-control is like a muscle: it weakens each day after you use it. How he came to the conclusion that this would lead someone to eat pizza as a post-workout snack is anyone's guess because, unfortunately, he doesn't attempt to explain it. It's just his opinion.

Next, he attempts to make his point using some science:

"Yes, although the muscle-fat relationship is often misunderstood. According to calculations published in the journal Obesity Research by a Columbia University team in 2001, a pound of muscle burns approximately six calories a day in a resting body, compared with the two calories that a pound of fat burns. Which means that after you work out hard enough to convert, say, 10 lb. of fat to muscle—a major achievement—you would be able to eat only an extra 40 calories per day, about the amount in a teaspoon of butter, before beginning to gain weight. Good luck with that."

Cloud's flippant dismissal at the end of this paragraph could be taken as self-mockery because no one can convert fat to muscle. The physiological process does not exist. You can lose fat (atrophy) and gain muscle (hypertrophy), but you can't convert one type of body tissue into another. Furthermore, the Columbia research has not been proven conclusive. Brad Schoenfeld, in an in-depth review of the TIME article on his blog Workout 911, cites two studies showing far greater differences in metabolic properties.

"In a study done at Tufts University, Campbell and colleagues reported an increase in lean body weight of 3.1 pounds after 12 weeks of strength training increased resting metabolic rate by approximately 6.8%. This translated into an additional 105 calories burned per day. Do the math, and that equates to approximately 35 calories burned for each pound of added muscle. A study by Pratley and colleagues came to a similar conclusion on the topic. A similar four month strength training protocol resulted in a gain of 3.5 pounds of lean muscle. Metabolic rate showed a resulting 7.7% increase, correlating to a metabolic-heightening effect of muscle of approximately 34 calories."

Cloud does manage to quote a lot of credentialed people, but he does so in a way where he either uses their quotes out of context or he interprets them in a way that's just plain wrong. For example, let's use his analysis of why running could be worse for weight loss than "sitting on the sofa knitting."

"Some of us can will ourselves to overcome our basic psychology, but most of us won't be very successful. 'The most powerful determinant of your dietary intake is your energy expenditure,' says Steven Gortmaker, who heads Harvard's Prevention Research Center on Nutrition and Physical Activity. 'If you're more physically active, you're going to get hungry and eat more.'"

True, you will be hungry and might eat more. What he leaves out is that not only can you eat more, but at some point, you need to eat more to lose weight. At Beachbody, this is one of the most difficult principles we have to teach our customers. At the beginning of an exercise-induced weight loss program, we restrict calories. As a person's body composition changes, so does that person's need for caloric consumption. It's not uncommon for our customers to double the amount of food they need to eat to keep their weight loss moving once they get into good shape. This simple physiological fact renders Cloud's argument moot.

And not only do individual caloric needs change, but so do nutrient needs. In my experience, the need for more nutrient-dense foods seems to create cravings for healthier foods that are nutrient dense. And since these foods tend to be less calorically dense (because they are often plant based and contain fiber), the most common scenario among our customer base is that people become less hungry over time because they're eating foods which keep them full longer.

Cloud follows this with an about-face, making a point that if people moved more, they could exercise less. Ignoring the fact that all movement is considered some form of exercise, Cloud uses some studies that showed kids who got less recess time spent more personal time exercising, and thus stayed on par with their weight loss, than those who got more recess—not exactly a damnation of exercise.

Then he actually champions exercise with the following statement:

"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."

This seems like a strong testament from an article that began as anti-exercise. He further drives home the need to exercise with the following paragraph:

"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?"

Huh? Who defined exercise as the need to "stress our bodies at the gym"? Wasn't this the same guy who had just told me that I'd be better off knitting than going for a run? It seems like the entire point of the article was for Cloud to publish an excuse so he wouldn't have to go to the gym anymore. He then proceeds to ask himself this exact question.

"This explains why exercise could make you heavier—or at least why even my wretched four hours of exercise a week aren't eliminating all my fat. It's likely that I am more sedentary during my nonexercise hours than I would be if I didn't exercise with such Puritan fury. If I exercised less, I might feel like walking more instead of hopping into a cab; I might have enough energy to shop for food, cook and then clean instead of ordering a satisfyingly greasy burrito."

The funny thing is that over the course of the article he actually seems to have convinced himself that he should exercise, only differently. He simply became befuddled on the type of exercise that he should be doing to get rid of his belly. It's more like an article to promote periodizational exercise, even though he doesn't mention it. He admits his confusion:

"Actually, it's not clear that vigorous exercise like running carries more benefits than a moderately strenuous activity like walking while carrying groceries."

Here we would agree, as it is unclear, especially without defining the intensity of the run or the amount of weight in groceries being carried. Not to mention the duration or the way you structured your daily tasks. What's become clear to me, by this point, is that the author needs a personal trainer. But he doesn't need one who takes him through workouts; he needs one who would plan an effective program for him. Cloud sums it up:

"In short, it's what you eat, not how hard you try to work it off, that matters more in losing weight. You should exercise to improve your health, but be warned: fiery spurts of vigorous exercise could lead to weight gain."

Again, he has it wrong. He's admitted a need to eat better and to exercise; he just simply doesn't understand the process. All his self-flagellation reminds me of the colloquial definition of insanity, "doing the same thing over and over again expecting a different result." What this author really needs, if he wants to lose his belly, is a Beachbody program.

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