Why Counting Calories Burned by Exercise Can Sabotage Your Weight Loss
I’m a big fan of calorie tracking to lose weight. This process is quite powerful … with one exception. Here’s a creepy case where the mere thought of calories can overwhelm your progress.
We’ve talked about how using exercise alone for weight loss is probably a poor use of your time , and more and more studies seem to support this notion.A 2011 study published in the American Journal of Medicine concluded:
Moderate-intensity aerobic exercise programs lasting 6–12 months cause moderate weight and waist circumference in overweight and obese people. Our results indicate that isolated aerobic exercise is not an effective weight loss therapy in these patients.
As Dr. John Briffa, author of Escaping the Diet Trap , notes on his blog , a 2010 study by the International Journal of Obesity found that it took 35 hours of cardio to lose one pound of fat without any dietary intervention. Okay, exercise without diet is probably ineffective, but why?
Exercise doesn’t make us hungrier
One hypothesis is that exercise leads to hunger, which leads to overeating, which negates the calorie deficit that occurs in the first place. Gary Taubes, author of the controversial book Why We Get Fat and notorious carbohydrate demonizer, says this idea is at the heart of “increased appetite.” We’ve all done this before, so this is certainly a plausible claim, but let’s see what the research has to say.
In a 1997 study by the British Journal of Nutrition, participants were divided into three groups: one group did high-intensity cardio, the other did low-intensity cardio, and the third group did not exercise at all (the control group). The researchers asked participants to rate their hunger, then took them to a buffet and asked them to eat as much as they wanted.
If the exercisers were to really “whet their appetite,” not only would they rate their hunger higher than the control group, they would eat more. But none of this happened – there was no statistical difference between hunger estimates or food intake in any of these groups.
This research was not an anomaly. Further studies, such as this study in the journal Sports and Science Medicine,this study at the Proceedings of the Nutrition Society, andthis metabolicstudy – clinical and experimental, had similar methodologies and results. They divided the participants into different exercise groups and a control group (not exercising), and then sent them all to the buffet. They all found that exercise not only does not increase the feeling of hunger, but in some cases helps to curb the feeling of hunger.
This leads to a number of obvious questions. Where can I enroll in one of these buffet studies (control group please)? But more importantly: what the hell is going on?
… But we will still eat more
In theory, exercise should result in more calories burned, less hunger, and more weight loss , but it really isn’t.
There are two studies that provide a compelling explanation for this mystery at the Scooby-Doo level. While they have similarities to previous ones, this time the researchers asked subjects to think of exercise and food in terms of calories.
In this2010 study by the Journal of Sports Medicine and Physical Fitness, researchers asked subjects to eat the same amount of calories they burned after exercise. As a result, they ate two to three times the actual amount.
In another study, researchers asked subjects to exercise and then have fun and then keep a food diary. The experimenters then translated the food logs into calorie equivalents. On paper, the entire group seemed to be in a general calorie deficit. However, when the participants’ final weights were measured, no signs of weight loss were found.
These studies showed that the participants’ potential appetite suppressing activity did not actually lead to weight loss due to what I called the Heisenberg Exercise Rule:
For many, simply measuring calories from exercise negates the benefits of weight loss.
Simply translating exercise into the same currency as food – calories – makes people subconsciously place their values in one giant book. In this book, calories act as the currency that provides additional food choices. For example, you can turn thirty minutes on a treadmill into one Krispy Kreme.
The problem here is that people tend to simultaneously overestimate the calories burned from exercise and underestimate the calories they consume. Accurately calculating calories versus calories burned is a difficult skill to master, and judging those numbers can convince you to make food choices that you would not otherwise.
So while exercise can physiologically reduce hunger and increase your overall calorie deficit, putting everything in “calories” psychologically encourages you to eat more calories than you burn.
And in fitness, when physiology and psychology go head-to-head, psychology almost always wins.
In my experience as a fitness trainer, I’ve noticed that those who successfully lose weight with just cardio don’t even think about calories. They just picked a new sport or activity and started losing weight, almost by accident.
Conversely, those who often play sports, claiming that the scales never move, become obsessed with calories. This is usually the person who feels like the Starbucks Caramel Frappuccino is “earned” after heavy cardio.
How to fix this problem
It is important to emphasize that we are not saying that calorie counting is bad. Again, tracking your calorie intake is a powerful technique that we encourage. However, evaluating the calorie intake of your workout can be the start of a bad mentality: thinking of food as a reward for calories burned. It might work for advanced dieters, but this is the recipe that most doesn’t work .
But you can still reap the health benefits – even the calories burned from exercise – if you keep the following in mind:
- Instead of calculating “calories burned” on a daily basis, do it weekly or use an activity ratio . You’ll be more likely to avoid spontaneous food decisions because you have converted exercise and food into “calories” currency.
- As Dr. Briffa suggests, think of aerobic exercise as something you do for health or entertainment , not for the calories you burn.
- If you exercise with the explicit goal to lose weight, think about how to give priority to strength training, as they will bring a much higher return on time spent on your efforts.
- As we mentioned in our Exercise Versus Diet article , remember that weight is lost in the kitchen, not the gym.
Exercise should be done for your overall health and longer-term (i.e., non-daily) weight loss goals. When this exercise becomes a number in your calorie diary, it loses its meaning.
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