Feel Better, Feel Stronger, Go Further
The Dodge Challenger Hellcat Red Eye is an amazing machine in a lot of ways. One of the most interesting facts I’ve read about it is that if you run it at wide open throttle, it will burn through 22 gallons of fuel in 13 minutes. There’s no sense of self preservation, no holding back, just turning 48,648 calories into acceleration and speed every minute. Imagine if you could throw yourself into the activities you love without worrying about having the energy to continue until you’re absolutely empty?
Without changes to how humans experience fatigue, that actually sounds like a pretty miserable experience.
Whether running, cycling, playing soccer, lacrosse, or whatever it is your love, there’s an above average chance that you’ve experienced the sensations of starting to run out of gas. You might not have meant to push hard, but those gently rolling hills started to add up as time ticked by, and suddenly each hill is feeling harder than the last, you’re not able to muster the strength that you had just a couple of hills ago, you’re starting to question whether you should pull over for a bit to recover, maybe you’re even having a hard time keeping your thoughts straight. All of these are elements of fatigue. Unlike the Challenger, you have evolved mechanisms designed to help you conserve energy, to prevent you from going full gas until your tank is completely empty.
You can do something the Challenger can’t, though. You can fuel while you’re going hard.
In terms of stored energy within your body, there are really only 2 choices: carbohydrate and fat (technically 3, but for the sake of argument let’s assume that you won’t want to burn muscle/protein to fuel yourself). Unfortunately, these energy sources are not created equally, and are not perfectly interchangeable. As the intensity of what you’re doing increases, the share of the calories you’re burning that come from carbohydrate will increase. It’s easy to think of things in binary terms, including the energy source our body uses to support activity, but in the case of energy usage it’s more like a series of faders than a switch between these two energy substrates than it is a switch between carbs and fat.
Though we have literal days of energy in the form of stored fat, our stored carbohydrate reserves (glycogen) are much, much lower. These lower reserves mean that the brain has evolved some powerful mechanisms to protect and conserve them, including the introduction of negative feelings that make you want to back off, or quit. Your brain does have a selfish reason for trying to trick your muscles into preserving those glycogen stores: your brain is a glucose hog. On average, the brain consumes 130g of glucose per day, that’s 520 calories per day just keeping that big, beautiful brain running. Because fatty acids are not able to cross the blood-brain barrier, the days and days of energy we have stored in the form of fat isn’t much use to it without additional processing, so the brain gets very protective of stored carbohydrate.
Glucose is delivered to your brain and muscles in the blood, so in a way, it’s your blood glucose that makes the difference, more so than just your stored glucose. Taking in simple carbohydrates, whether running, cycling, or during other moderate to intense activities, gives your body a source of fuel that lets it avoid tapping into its stored reserves. There are limits to how much carbohydrate your body can process per hour (a general guideline is 60g of glucose and 30g of fructose per hour) but supplementing with carbohydrate from external sources means your body won’t have to start tapping into its stored energy as quickly, or as deeply.
You might be asking “Why specify simple carbohydrates as the thing to supplement?” and it all comes down to what your body is able to process. During exercise, your body becomes a walking economics experiment, trying to most efficiently utilize limited resources to produce the greatest benefit. When you’re active, your body shifts its resources away from digestion to supporting your activity, and as this happens it becomes more important to take in fuel that requires less processing by your body to get it to a state where it can be absorbed in the small intestine. Foods like granola bars, dried fruit, even candy bars are great sources of carbohydrate during a lot of lower intensity activities, but they may require too much digestion to be usable, which means in the best case they’re just siting in your gut until the intensity level decreases, or worse, it could mean that you’ll experience GI distress as a result. Though not a great cornerstone for a healthy diet, in these applications it can be extremely beneficial to leverage highly processed carbohydrate, as your body can absorb it quickly and easily during intense activity.
You want to enjoy the activities you love. Sometimes those activities are challenging, and in the moment, you might be questioning the reasons you choose to do it in the first place, but there’s a simple way to make them more enjoyable, and that’s giving your body the fuel it needs to do what you ask of it. A healthy, well-rounded diet is the foundation of this, but supplementing your activities with carbohydrate is a really easy way to leverage your body’s natural processes to feel stronger while you’re training or competing and feel better after you’ve finished. Fueling your activities gives your muscles and brain the energy they need without burning through your body’s stored resources, which helps manage the mental aspects of fatigue, allowing you to go a little further.
You may not be able to hold the pedal to the floor until you’re completely out of gas, but you can do something that would be the envy of any high-performance vehicle in a race: you can refuel without having to stop.
