NSCA Nutrition Calculations, Calories to Lose a Pound, Cunningham Equation, and More

calorie deficit calories electrolytes energy balance energy systems glycogen intra workout macros muscle protein synthesis nutrition performance post workout pre workout Jun 10, 2022

Edited By: Danielle Abel, MSN, CSCS

Proper nutrition is just as important as a well-designed strength and conditioning program

Calories from food provide the body with energy to be able to perform the movements required for sport.

Calories & Macros

In order to understand nutrition, we need to start with macros. Macros stands for macronutrients, in which there are 3 (a 4th macronutrient, alcohol is 7 calories for every 1 gram, but it’s not important to know this for the CSCS exam)

  • Protein
    • Every 1 gram of protein contains 4 calories (kcal)
  • Carbohydrates (Carbs)
    • Every 1 gram of carbohydrate contains 4 calories (kcal)
  • Fats
    • Every 1 gram of fat contains 9 calories (kcal)

Track Your Intake

If you don’t already, consider tracking your intake using a macronutrient tracking app to help you been analyzing your diet and food. Simply download a tracking app, and start logging all the food and beverages you’re consuming.

Tracking for at least 1 week (bare minimum!) will give you an average intake over the course of your week because intake does tend to fluctuate. Tracking your intake will give you a better understanding of approximately how many calories you are consuming each day, along with the amount and type of macronutrients contained in the foods and beverages you’re eating. 

Having this baseline information for yourself can help you apply these concepts to the athletes you train. 

If you had a protein bar with the following macros, how many calories would this bar be?

  • Protein: 20 grams
  • Carbs: 8 grams
  • Fat: 2 grams

Protein 20g x 4 calories = 80 calories

Carbs 8g x 4 calories = 32 calories 

Fat 2g x 9 calories = 18 calories 

80+32+18 = 130 calories 

Nutrition for Performance

When working with athletes you need to understand the percentage of intake coming from the 3 different macronutrient sources

    • % of calories from protein
    • % of calories from carbs
    • % of calories from fats 

In the above example, it would look something like this:

  • 80 calories from protein / 130 total calories = 61.53% of energy from protein
  • 32 calories from carbs / 130 total calories = 24.61% of energy from carbs
  • 18 calories from fats / 130 total calories = 13.84% of energy from fats 
    • 61.53% + 24.61% + 13.84% = 99.98%

Calculating a calorie deficit to lose 1lb of fat

In order to lose 1 lb of body fat, there needs to be a total reduction of 3500 calories of intake over a given period of time. As a coach, it’s important that you recognize how to estimate how long it would take an athlete to lose 1lb of body weight.

In order to understand how to calculate a calorie deficit, you must be able to identify what the athlete's estimated total daily energy expenditure is (TDEE).

After you know what their TDEE is you will need to know what their average calorie intake is, and then calculate the deficit amount from here. 

For example, if a female athlete wants to lose 2lbs she will need a deficit of 7000 total calories for a given period of time. 

If her estimated energy expenditure is 3500 calories per day, and she’s placed in a deficit at 3200 calories per day (a 300 calorie deficit per day) it will take her approximately 23 days to lose 2lbs if she’s extremely precise with her intake & adherent to the targets you provide 

  • 7000 total calories / 300 calories per day = 23.33 days


Protein is made up of amino acids. There are 20 total amino acids, 9 of which are considered essential amino acids (EAAs), meaning we must obtain these amino acids from our food. 3 of these 9 amino acids are considered branch chain amino acids (BCAA). The other 11 amino acids are either conditionally essential or non-essential. 

  • Conditionally essential = must be obtained from the diet during times of stress & illness
  • Non-essential = the body can manufacture these amino acids 

Complete Proteins

Consuming protein sources that are considered “complete,” meaning they contain all 20 amino acids is important for building muscle. 

The 9 essential amino acids 

  • Histidine
  • Isoleucine
  • Leucine
  • Lysine
  • Methionine
  • Phenylalanine
  • Threonine
  • Tryptophan
  • Valine

The 3 branch chain amino acids (BCAAs)

  • Valine
  • Leucine
  • Isoleucine

When we think about building muscle, the 3 BCAA’s valine, leucine, & isoleucine are important for muscle protein synthesis (building muscle). 

Leucine has been shown in research to have the biggest impact when it comes to muscle protein synthesis. 

A precursor to leucine, hydoxymethylbuterate (HMB), is sometimes contained in protein supplements as well. However, it’s best to consume good quality protein sources in general, whether that be from whole foods based protein sources (like meat, fish, dairy, eggs, quinoa, etc.) or protein supplements. 

When looking at protein supplements, it’s important to recognize the percentage of BCAAs contained in the supplement. In general, lower-quality protein supplements contain less % of BCAAs. Supplements like “isolates” that contain less carbohydrates & contain a higher % of BCAAs.

Calculating protein recommendations for athletes:

You’ll need to know their primary sport & their body weight in pounds, then divide this by 2.2 to get their body weight in kilograms. 

  • Endurance athletes: 1.0-1.6 grams per kg of body weight
  • Strength athletes: 1.4-1.7 grams per kg of body weight 
  • For weight loss or muscle gain, you can increase protein above these ranges 

Keep in mind that the RDA (Recommended Dietary Allowance) recommended daily protein intake of 0.8 grams per kg of body weight per day, is not adequate for athlete protein intake for optimizing muscle protein synthesis.

Looking for a step-by-step program to help you learn the  NSCA’s Nutritional Calculations step by step? Then you might want to check out our online CSCS Prep Course here

Carbohydrates & Glycogen 

Carbohydrates in their most simple form are a chained molecule of carbon, hydrogen, & water (carbo - hy - drate). Carbohydrates are broken down into glucose (blood sugar). Carbohydrates can be immediately used for energy by the body within the cell with the help of the energy uptake hormone, insulin. 

Carbohydrates can also be stored for future energy needs. Short-term storage of carbohydrates occurs when individual glucose molecules are linked together to form glycogen, which are stored in muscle & liver tissue. 

Long-term storage of carbohydrates occurs when blood glucose is converted into fatty acids and stored within adipose cells called adipocytes. 

Glycogen storage is limited

Glycogen storage is limited, on average 1200 to 1500 calories can be stored within the muscle or liver. So depending upon the sport, an athlete may require refueling in order to maintain the movement needed to complete a session, competition, or meet. 

For example: If running burns 100 calories in 10 minutes, an athlete running a half marathon would use up their glycogen stores during this event if they did not consume any additional energy during their event. At this point, when glycogen stores within the muscle & liver have been metabolized, this is referred to as “hitting the wall.”

So as a coach, you need to understand why & how to provide intra-workout nutrition recommendations to athletes to help them spare or replenish their glycogen stores. 

Intra-workout nutrition

Carbohydrate-containing foods, beverages, or supplements that are consumed during a session, competition, or meet. 

  • For example:
    • Gatorade
    • Banana
    • Carbohydrate containing bar

In general, consuming 30 to 90 grams of carbohydrates is recommended, or 1 gram of carbohydrate per minute (60 grams in 60 minutes/1 hour). It’s best to consume these carbohydrates from a mixture of glucose and fructose (Gatorade = is a blend of glucose & fructose).

If an athlete is running a half marathon at a rate of 7 mph, in 2 hours, they would be expending approximately 700 calories per hour, so they would need 1400 calories during the event.

Remembering that the average person has 1200to 1500 calories of glycogen available it would be important that this athlete supplement some carbs to prevent running through their full glycogen stores during the event. 

However, carb consumption during the event will be limited by digestion because a great deal of blood will be shunted away from the digestive tract and mobilized towards movement, so using the 30-90 grams recommendation can be helpful to avoid an upset stomach during the event. 


The main electrolytes we’re concerned about are glucose, sodium, & potassium (sugar, salt, & potassium). When we sweat, we are perspiring water, sodium, & potassium through the pores of our skin. 

So just replenishing with water during an event can put an athlete at risk for hyponatremia (low sodium content and increased water content within cells). So replenishing with electrolytes helps to promote adequate fluid & electrolyte balance, which in turn also reduces the risk of hitting the wall (when stored glycogen is completely used up). 

Encouraging athletes to supplement with foods or beverages containing not only water but electrolytes as well is more optimal from a performance standpoint. 

Cunningham Equation

The Cunningham Equation allows you, as the coach, to calculate an athlete’s resting metabolic rate or RMR. So that you can understand what their approximate total daily energy expenditure is. 

Keep in mind that basal metabolic rate (BMR) and resting metabolic rate (RMR) are different. 

  • BMR = must be fasted, the energy needed to just keep you alive (brain & body function) with no other energy demands (from being alert & awake, eating, etc.)
  • RMR = does not require fasting, does include the energy needed to digest food 

The Cunningham Equation uses an athlete's lean body mass to calculate total daily energy expenditure vs. other calculators that do not take into account lean body mass. 

500 + (22 x kg lean body mass)

If you have a 190 lb male athlete, he would be approximately 86.4 kg. (190 / 2.2)

Next, you need to determine the % of body fat, let’s say this athlete is 18% body fat you would take 86.4 kg x 0.18% = 70.85 kg lean mass

500 + (22 x 70.85kg) = RMR of 2058.6

Then, we need to add an Activity Factor (1.2-1.9) to find his Total Daily Energy Expenditure (TDEE). 

If we use 1.5, we would take his RMR and multiply it by his estimated activity factor. So in his case, let’s just say it’s 1.5. So, 2058.6 x 1.5 = 3088 calories per day. 

Pre-Competition vs. Pre-Training Nutrition

The goal of pre-competition nutrition is to maximize glycogen storage, not to maximize muscle protein synthesis. In this case, we want to optimize blood flow to the skeletal muscle from a performance perspective. If protein & fats are consumed ahead of a competition then the body is using blood for digestion & reducing the blood available for skeletal muscle contraction. 

Carbohydrate & protein loading (for the average 150lb athlete). In general, the carbohydrate doubles every 2 hours. 

  • 1 hour before a competition
    •  35 grams of carbs 
  • 2 hours before a competition
    • 70 grams of carbs
  • 4 hours before a competition 
    • A range of 70-270 grams of carbs (140 average)
    • A range of 10-17 grams of protein 

The goal of pre-training nutrition is to maximize muscle protein synthesis following training session recovery, but we need to be mindful that blood will be diverted to the digestive tract to break down protein & fats (which take longer to digest than carbs).

Energy Systems

In closing, keep in mind that an athlete’s given activity will influence the primary energy system utilized. 

Aerobic Activity (Higher fat utilization):

  • Endurance
  • Lower intensity
  • Longer duration
  • Oxidative in nature 

Anaerobic Activity (Higher carb utilization):

  • Strength
  • Higher intensity
  • Shorter duration
  • Glycolytic in nature 

Support & Courses Available

Ready for more support about nutrition to help you prep for the CSCS exam? Join our Facebook Group “Strength and Conditioning Study Group” here. 

Ready for even more? Our 24 module CSCS Prep Course has Chapters 9 and 10 completely laid out for you with even more content than what we’ve provided here, plus chapter quizzes to help you pass the NSCA exam, click the link here to check it out. 




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