Great! But the reason you are probably reading this article is because you want to lose weight while or even through exercising. I hate to be the one to tell you, but first let me burst this bubble, you probably won’t. The title of an editorial in the scientific journal British Journal of Sports Medicine actually says it all: “You cannot outrun a bad diet”.
Your weight and therefore being overweight is just the simple balance between your energy intake and your energy expenditure. So, it seems logical that when you increase your energy expenditure through exercising you will automatically drop weight. However, unfortunately it’s not that simple. To explain why this is the case, we first need to focus on the different types of energy intake.
Three types of energy
Your body can rely on three types of energy: carbohydrates, fat and protein. The latter is not such a good idea, because those proteins are actually essential for muscle recovery. This only happens when the first two options have run out. You might have experienced this after a (too) aggressive ride and your clothes smell like ammonia.
The second option, carbs, is the most efficient one. The problem with carbs is that the storage is not that big. An untrained body has about 300 to 400 grams of carbs stored in the liver and muscles, while a trained individual can double this storage capacity. The higher the intensity gets, the more your body relies on burning carbs. When you exercise at your power or heart rate threshold you will ransack this storage completely in about an hour, but the maximum uptake is only 90 grams per hour. But don’t be mistaken that your body only relies on carbs at a high intensity, because it also burns some carbs at a low intensity or at rest. For example, your brain can function on carbs only.
The real energy bomb is fat. The storage is nearly infinite even when you have a low percentage of fat. The only problem with fat is that it takes a lot of oxygen to let energy originate. Exercising on a high intensity, your body almost solely depends on burning carbs, but on a low intensity your body burns mostly fat. If you want to lose weight, exercising at this low intensity is the only way to do it. When burning carbs, you just don’t drop weight, because your body will only be craving to replenish your carb storage in the liver and muscles. This process cannot be altered and is mostly unconscious.
Low intensity burns fat
Take also into account that the better your stamina gets, the higher the intensity will be at which your body can still rely on burning fat. So, especially for those who start exercising with the idea to lose weight, the intensity should be really low to actually burn fat. Even so low that it doesn’t feel like exercising at all and the duration would have to be enormous to perceive any effect.
Here, we have addressed the problem regarding why you probably don’t lose weight through exercising. But there is more. If you exercise, you cannot just add those burned calories on top of your normal energy expenditure. Studies show that the basic metabolism of people who exercise is lower. It seems that when we have done a workout we have a tendency to reward ourselves by being less active and even indulging in unhealthy food.
So, what do I have to do?
By now you are probably thinking that the above does not apply for you. You are probably someone who will beat the statistics and start exercising on the exact low enough intensity with a long enough duration and will also conquer the mental hurdles.
Even then, losing weight through exercising just doesn’t make sense. It’s like eating soup with a teaspoon. It can work but it takes ages and you will probably not even enjoy the soup. If you want to enjoy exercising, then doing it on an extremely low and monotonous intensity for a long duration is not the way to do it. Enjoyment in what you do is actually one of the strongest and even scientifically proven motives for exercise persistence. Finally, it would be a pity to only exercise on a low intensity because you will miss all the other benefits for your stamina by also exercising on a high intensity.
So, if you want to lose weight you need to change what and how much you eat. If you’re struggling with being overweight, there is something wrong with your diet. And start exercising because of all the associated benefits and the fun of it. Just don’t try to eat soup with a teaspoon, although you will probably lose weight by doing so.