Is Your Fueling Strategy Holding Back Your Performance?

Let us focus on a specific aspect of nutrition—what you consume during training and racing. We're not talking about your regular meals or pre-race carb loading strategies. Instead, we're focusing on every substance you take in while engaging in endurance sports.

Understanding Calories

A calorie is a unit of heat used to measure energy.  In the world of nutrition and exercise, calories refer to energy that is used to fuel movement, like gas for a car. When it comes to fuel for endurance activities, we often talk in grams of carbohydrates. For example, 1 gram of carbohydrate provides 4 calories of energy.  So, if I mention that your body can absorb 90 grams of carbs per hour during intense activity, that equals 360 calories per hour (90 grams x 4).  Of course, every athlete’s energy needs are unique… but can be determined through a Metabolic Assessment.   https://www.keystoneendurance.com/assessments

Energy: Potential vs. Kinetic

Energy is essential for endurance sports. There are two types of energy: potential energy (stored energy) and kinetic energy (energy in motion). Your body

works by converting potential energy into kinetic energy through a series of chemical

reactions. This is how your muscles move. 

Your body generates heat as it converts potential energy into kinetic energy—this is normal and happens in all endurance athletes. Essentially, you're a highly complex system of chemicals working together to produce movement. 

Envision The Body as an Automobile

• Muscles: The "engine" generating movement using fuel (glycogen).

• Bones: The "chassis" connecting muscles and transmitting forces.

• Cardiovascular System: The "fuel pump and lines" delivering energy to muscles.

• Brain: The "computer" managing all systems and needing its own energy.

  
  

Fuel Tanks in the Body

Now, let's talk about the body’s "fuel tanks." This is where things get a little more complex than in an automobile: 

• Muscle Glycogen: Your muscles store glycogen which can be used for quick energy. This, like all body fuel tanks, does not have overflow capacities. The glycogen stored in this tank is not shared with other organs and can only be used by the muscles. 

• Liver Glycogen: The liver stores glycogen as well and can release it into the bloodstream when needed. The smallest of all tanks. This glycogen can be used by other organs like the heart, brain, lungs, etc. that need energy.  

• Fat Stores: Your fat tissue is another energy source. While it’s a large storage tank, it’s a slower-burning fuel used in aerobic level “easy” efforts and not as efficient for anaerobic “hard” efforts requiring quick bursts of energy.

• Gut: Your gut is the most complex tank. It’s where nutrition gets absorbed into your bloodstream to be used as fuel. This is the most temperamental part of the system, and getting the fuel into your bloodstream can be tricky.

In simple terms, the process is carbohydrate to glucose to cells. When the cells are full, any extra glucose is converted to glycogen and stored in the body's fuel tanks. Glucose is the main source of energy for cells.    

When carbs are ingested, they are broken down into glucose. Some of this glucose is sent by the liver into the bloodstream to cells throughout the body. The liver takes the extra glucose and converts it to glycogen and stores it for later use, filling up the liver “tank”.  In between carb ingestions, when energy is needed, the liver breaks the glycogen down into glucose and releases it into the bloodstream. This lowers the amount of fuel in the liver tank until more carbs are ingested and the cycle repeats. This process is similar for the muscle's “tank” with the exception that glycogen that is stored in muscles is not shared and only used by muscle cells.   

Understanding Intake

When we talk about "intake," we mean what you consume—what you put in your

mouth and swallow. During a race or intense training session this could include

hydration mixes, electrolytes, gels, chews, solid foods, candy, etc. This intake is critical because it feeds the gut’s fuel tank. The process of getting that fuel from the gut into the bloodstream is called "absorption." Let’s look at the gut’s role. 

The Gut’s Role in Fueling

Imagine your gut as a bucket with a straw delivering fuel to your body. This bucket needs to never run dry and constantly needs to be replenished (same as taking in nutrition during an endurance event).  If you overfill that bucket, it can cause an issue, (too much nutrition = GI issues=port-a-potty) or if the hose gets clogged (taking in the wrong type of nutrition), the delivery of fuel slows down or stops. Similarly, if you overload your gut, it can’t absorb nutrition effectively, and you might "crash/bonk." 

Wrapping Up

Our bodies are energy machines that rely on different fuel tanks: muscles, liver, fat

stores, and the gut. Managing these tanks and the absorption process is essential for maximizing performance and avoiding "crash and bonk" moments.  As endurance athletes, we know that trying something new on race day is a no-go.  So,

understanding and knowing your best fueling strategy is important for peak performance!

Let's Unlock Your Potential!

Coach Chet