If you follow health news, there are often articles that discuss how much exercise it will take to burn off a cheeseburger. The motivation behind these articles is to dissuade you from having that cheeseburger, logically at least, because it supposedly takes a “5.6 mile hike” required to “burn” it off.
When I see these articles, I get the good intent. Most people without a science background don’t get the E=mc2 concept that matter and energy, or Calories, are the same thing. Most people don’t think in Calories or have a very good abstract idea of what they are. It’s pretty simple though in terms of what you need to know for nutrition: fat has 9 Calories per gram, alcohol has 7 Calories per gram, protein has 4 Calories per gram, and carbohydrate has 4 Calories per gram. Fat is, thus, considered an energy-dense nutrient due to the high concentration of calories per unit of mass (grams). Add up your Calories from each nutrient previously listed, and that’s your Calorie score.
However, every time I see these sorts of articles, I feel like I am banging my head against the wall out of frustration because they miss the teaching point. I also don’t think these comparisons are very effective. Here’s why:
1) A 210 lb male uses more energy to move about each day and to live than a 115 pound female, so the “5.6 mile hike” isn’t even accurate for most people anyway. Who is this specifically targeting, then? I can’t tell you that answer, as I was never taught. If you know, please comment below. Does this “5.6 mile hike” refer to a small female or a large male?
2) Exercise breaks down muscle. If you are doing muscular endurance exercise, maximum strength training, cardiovascular training, sprinting, flexibility, or anything physical, including walking, you are breaking down muscle. That is how you move. Energy is released as heat and as locomotion. So, depending on the type of exercise you perform, your body’s response is to rebuild that muscle back to normal and supercompensate it with either more energy storage or protein storage as well as create more mRNA for enzymes that favor the types of exercise you do.
Definition: mRNA is basically an intermediate between DNA and protein expression in the body. They call this the “transcription” process of DNA in school (ie, DNA to mRNA; mRNA to protein is called “translation”).
3) People who are choosing the cheeseburger, even with this information do not make the right choice and are very aware it is not the right choice. People sometimes eat for reasons other than nutrition, such as social eating, emotional eating, rebellious eating, convenience eating, lack of time or poor planning, etc. So it doesn’t matter what logical information you put on the product. Perhaps a better campaign would be “talk to a friend instead of eating this cheeseburger alone.”
So what’s my point? Any time you create breakdown in your body, it has to rebuild. If you don’t let your body rebuild, either because you are over-exercising or not consuming enough Calories for that exercise, it creates a stress response that basically slows down your metabolism until your body DOES rebuild itself. The stress response can include elevations in cortisol, which raises blood sugar.
The exercise you did tells your body to actually store weight in the form of muscle.
Wait, muscle? That’s good right?
It is for some of the population. However, what about people who are already overweight or obese and have a lot of muscle and a lot of fat? Now is not the best time to be building muscle because you will not be losing weight. In fact, it may slow your weight loss progress by slowing the speed at which the pounds come off! Any excess weight on your frame increases the work your heart has to do to pump blood around your frame. Your cardiovascular system just gets more inefficient the larger you are for your frame size, muscle or fat.
That said, exercise at any size helps improve overall health dramatically, so if you’re not at a good point in life to make better food choices, exercise will prevent you from experiencing many of the negative effects of being overweight or obese. It can reduce blood pressure, increase HDL cholesterol, improve blood sugar sensitivity (attention diabetics!), acutely reduce symptoms of depression or anxiety, improve circulation, lubricate joints to reduce joint pain, and many, many other benefits beyond the scope of this post.
“But who cares about weight? Shouldn’t we just care about lean mass? Doesn’t muscle weigh more than fat?” (Actually, a pound of muscle and a pound of fat weigh the same. Muscle is more dense though and takes up less volume.)
Yes, to an extent. But from a metabolic efficiency standpoint, frame size is important to think about if you do not want to be carrying around a lot of fat mass with your lean mass to mask how hard you work out. No one will see your muscle striations if they are behind a lot of fat.
So, in summary, exercising to “burn” off Calories is not a good idea. You will end up gaining weight over time, albeit muscle weight.
Instead, think of exercise as Calories you need to consume on top of the minimum amount of Calories you need each day. If you don’t consume them, your body slows down your metabolism until it makes that energy available to remodel your muscles with what it has. This is basically a state of “over-training” or “weight loss stalling.” They are pretty similar metabolic states, in my opinion. If you exercise and don’t eat, your body slows down.
Think of the exercise first, and then think of what you have to do to from a dietary standpoint to replace what you lost during the exercise. Again, if you don’t replace what you lose, your body will slow you down until you do. Don’t think of it as “eat the cheeseburger” then “I have to punish myself by abusing my muscles this many times.” It’s not even the exact same molecules of energy from the food. If you haven’t trained to store more energy in your muscles, that cheeseburger just goes to your waist, and if you’re not trained to expend large amounts of energy during exercise (as very fit people can), then you won’t “burn” that food off. You’ll just break your muscles down some.
Yes, exercise burns some Calories, but it is not significant enough to eat pretty much any food you want. Food choices are paramount.