Our bodies are pretty amazing when it comes to the different sources we can use for fuel.
While carbohydrate and fat are our primary sources of energy, we can also burn ketones, lactate, and even protein in a pinch.
As the term implies, metabolic flexibility refers to our body’s ability to toggle between fuels depending on the situation. For the most part, this means sugar or fat.
This is important because when your body can’t easily switch between fuels, you run into problems.
Let’s look a bit deeper.
SUGAR
- Also known as blood glucose. It is the main fuel source for our brains, as well as our muscles during heavy exercise.
- Sugar is like kindling; it burns quickly and has to be constantly replenished either from our energy stores or from our diets.
FAT
- Fat tends to get a bad rap, but we couldn’t live without it. We need fat in our diets, and it is especially important as our main form of energy storage.
- Fat is a slow-burning fuel, like a fire-log. While our capacity to store sugar is quite limited, even the leanest athlete has enough fat to keep them going for days and even weeks.
![kindling v log horizontal](https://powermeacademy.com/wp-content/uploads/2022/10/kindling-v-log-horizontal-50-1024x313.png)