Lesson 10, Topic 1
In Progress

Calorie Burn For The Athlete: For Educators

Michael Bewley September 19, 2020


Consuming the approximate number of calories that our body burns each day is the first step toward attaining peak performance.

Too Much or Too Little Energy

The body’s primary source of energy is carbohydrates (discussed in detail later) but, we don’t store many carbs in our body to use later for energy. However, we do have muscle and lean tissues (like our skin and other organs) and fat stores. Therefore, when your body runs out of stored carbohydrates, then it starts to break down both your protein stores (muscle) and your fat stores.

What is a Calorie

When you hear the word energy, think calories. Calories are nothing more than the body’s “gas” – the energy it needs to move from one place to another. While dieters curtail calories in hopes of shedding body fat, athletes must look at calories as fuel to perform at peak levels of intensity —  to get the body to grow and respond to training.

What is Metabolism?

Metabolism (also called metabolic rate) is the total energy needed for all of the chemical reactions in your body. It includes the energy you need to: think, sleep, breathe, digest food, blink your eyes, and to keep your heart beating – every little thing your body must do to function. Your metabolic rate depends on your age, gender, height, activity level, and how much muscle your body contains.

Consume Enough Calories

You may be thinking: That doesn’t sound good! And you’re right! As an athlete, there is never a good time when you would want to break down your muscles and other lean tissues. Therefore, unless you need to lose body fat, or if you weigh more than a healthy weight, then you want to make sure you are eating enough calories to support your current weight. Having enough calories keeps your body from using itself (muscle) for energy! The loss of lean muscle tissue will result in:

  • Increase in fat mass.
  • Reduced speed, strength & power.
  • Diminish performance capability.
  • Lead to over-training and possible injury.

Nutrition & Training Adaptation

If you get anything from this sports nutrition guide, get this: when you strength train, condition, practice, or compete, you are getting WEAKER, NOT STRONGER! When you train, you are depleting energy systems and breaking down muscle tissue through repetitive muscle contraction (ex, running, jumping, sprinting). Not until after you train and you begin refueling the body with the proper nutrients that optimal performance and recovery get facilitated through the body. We refer to this as “training adaptation,” which allows for the highest degree of speed, strength and power development, resulting in a more significant training effect and enhanced performance.

You may be left wondering, how many calories (energy) do I need? Scientists who study the body’s metabolism have created calculations that determine the body’s calorie burn and are the sum of three dimensions that include basal metabolic rate (BMR), daily activity level, and body composition.

What Is My Calorie Burn?

Critical Reload has developed a Performance Nutrition Calculator to assist with determining your daily calories needs uniquely specific to your metabolic rate, age, gender, height, activity level, and how much muscle your body contains.

The Performance Nutrition Calculator

Click the floating CALCULATOR tab on the right and enter your values in the Calorie Burn fields (PART 1-3). The calculator will determine how many calories you need daily in combination with your lean body mass and fat mass.


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