How Your Body Utilizes Food During Exercise

Have you ever wondered how your body utilizes food during exercise? If you’re anything like me, it’s definitely crossed my mind as I wonder what’s really going on inside my body as I work through endurance exercise and even fast, quick movements. Throughout a Sports Nutrition Course I took in college, I came to understand just how much the body uses fuel (ie. food) throughout the course of your body’s movement. I’m excited to share this information with you in hopes it will allow you to understand it better!

First, there are two types of exercise:

1. Fast, quick bouts of movement such as heavy weight lifting or the 100-meter sprint.

2. Slow, long bouts of movement such as longs runs, cycling, hiking, or more endurance activities.

Second, there are two types of fuel our body pulls from to sustain itself during these two types of movements:

1. Carbohydrates: This is any grain, vegetable, fruit, pasta, bread, etc. It’s energy is readily available and used for day-to-day tasks and movement. It’s the way you get most of your energy!

2. Fat: This is any nuts, seeds, avocado, coconut oil, etc. This is not your primary source of energy, like carbs, but it’s still used to provide your body with the necessary nutrients it needs.

Now, the way these two categories correlate, is that each type of exercise burns the fuel sources differently. In short, carbohydrates are great for fast, quick bouts of movement when your body needs energy and it needs it fast. In comparison, fat is best used in slow, long endurance activities. Contrary to popular belief, your body actually pulls more fat through endurance exercise than it does carbs. Why is this?

Let’s say you’re starting a run and you’re planning on running 6 miles. At first, your body needs quick energy to start, so your body pulls from your carbohydrate reserves… aka fast and quick energy. After a while, though, your body begins to deplete it’s stored carbohydrates. For long endurance, your body needs another source of energy to pull from when the carb bank gets low, which is where the fat comes in. Fat is broken down through oxygen. As more oxygen starts pumping through your body as heavy breathing intensifies, the fat can be broken down and utilized. Carbohydrates provide fast and quick energy but can’t sustain your body throughout hours of endurance. In fact, after about 90 minutes of exercise, your body needs more sustaining fuel as the carb reserves usually start to diminish. That’s why having good fat as part of your regular diet is so important.

A quick way to visualize this relationship is by using a bank analogy: Your checking account is like the carbohydrate reserves, while your savings account is like your fat reserves. When you want to make a quick purchase, let say, for a stand-mixer, you’d pull the money from your checking account and make the quick and easy purchase. On the other hand, say you were going to purchase a house. You would pull money from your savings account each month to pay for your mortgage over the longer period of time. This is a similar way to how your carbs and fats work during exercise.

The most important point is this: just like you use both bank accounts, your body uses both fat and carbs. Fat is not better than carbohydrates, and carbohydrates are not better than fat… both are equally important to the health of your body and the way your body performs.

Additionally, please don’t think that you won’t ever burn fat unless you are running or walking for up to 90 minutes. Like I said, your body uses both. The point is that after 90 minutes of exercise, your body primarily sustains itself on other fuel sources besides carbs, since your carb reserves will only last you so long.

In short, a balanced diet full of carbs and good fats helps sustain your body throughout exercise. One of the reasons I love my Granola Bites so much, is that they fuel my body with good fats, protein, and carbs. Although they are mostly full of good fat, they are great for sustaining you through long bouts of exercise by keeping you full and fueled. To my fellow women, I want you to be very conscious of fueling your body with good fats, since they are essential to our overall health in massive ways.

I hope in reading this, you feel more educated, informed, and most importantly, excited to fuel your body with whole foods that create a well balanced fitness and health lifestyle. Thank you for reading!