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Fueling A Champion: A Closer Look At Basic Sports Nutrition Concepts

2025, July 15

Macronutrients: Calories
The world of nutrition can be a difficult one to navigate. How many times has the media gone back and forth on whether eggs, milk, coffee, or oils are good or bad? The amount of misdirection and misinformation online is extensive. Gurus, influencers, health professionals speaking outside of scope, and many so-called “nutritionists” (which is a title that anyone can claim even if they have no education or certification)1 have made the landscape of nutrition information extremely polarized and plagued with not only misunderstanding but blatantly false and baseless claims.a

The goal of this article series is to help form a basic foundational understanding of simple nutrition concepts as they relate to sports performance.It is important to note that when it comes to nutritional recommendations, athletes are very different in many ways than the average person. Athletes place an incredible amount of demand on their body and must fuel more specifically for training, response, adaptation, and performance.2 Their fueling bases and concepts reflect this notion.b


aMany sports performance specialists have a credible formal education and/or advanced certifications in nutrition; the gold standard for specialized sports nutrition professionals is a Board Certified Specialist in Sports Dietetics (CSSD), second is a Registered Dietician (RD).

bAlways consult with a physician before making major changes to nutrition and/or supplementation, especially if you have a unique condition or take certain medications that may have interactions with certain nutrients.

Calories: Performance Fuel
Every human relies on calories for everyday functioning. Calories become usable energy in the body, necessary for everything from breathing and circulating blood, to movement and brain function, to growth, repair, and even sleep! 

In fact, a calorie is simply a unit of measurement for energy, the same way an inch is a unit of measurement for distance/length. For those curious, one calorie is defined as, “a unit of energy, often used to express the nutritional value of foods, equivalent to the heat energy needed to raise the temperature of 1 kilogram of water by 1 °C”.3 If a banana has 100 calories, that simply means it has the stored energy capacity of 100 calories of energy for the body to use and/or store. 

Any food with protein, carbohydrates, and/or fat contains calories; these are known as your macronutrients. We will go into these more in the next three articles, but protein and carbohydrates have 4 calories per gram and fats have 9 calories per gram.4 One pound of body fat stores around 3,500 calories of energy! However, it is important to note that not all calories are created equal; when comparing two different foods of equal calories and even equal macronutrients, they will have different vitamin/mineral/nutrient content affecting the overall quality of the food choice even though the energy it provides is the same.  

Calories For The Average American
The average American adult requires anywhere from 1,600 to 2,400 calories every day to maintain body mass and function.5 Contrast this with the estimated actual amount the average American adult consumes at 3,600-4,000 calories every day and you get a simple explanation for the obesity epidemic.6,7 In fact, today over 40% of all adults in the U.S. are obese; in the mid-1900s rates were only around 13%, meaning they have more than tripled!17

Calories For Athletes
Athletes obviously move a substantial amount more than the average sedentary person as they push their mind and body to their limits, so their bodies require more energy to maintain body mass and function (and even more so if the athlete is trying to increase muscle and/or improve performance). While finding a calorie amount that is always 100% correct is impossible due to constantly changing variables, there are many great estimation tools available for determining a starting point range.

Estimating Resting Metabolic Rate
The best starting point for determining an athlete’s total daily energy expenditure (TDEE) or caloric need is estimating their resting metabolic rate (RMR), which is simply how many calories their body uses when at rest. Once this number is determined, it can simply be multiplied by a physical activity level (PAL) number (discussed later) to closely estimate a daily calorie starting point. There are many methods for calculating RMR, the main ones are listed in our TDEE Calculator.8,10,11

It is important to note that no matter the test or measurement utilized, athletes and coaches will never take the number gathered as absolute or indisputable and will always adjust diet strategies based on outcomes.9 So while it might be awesome to use a more expensive prediction method, the only outcome is a possibly more correct starting point that will need adjustment anyway. These methods simply provide important starting point insights. Because of this, prediction equations are very commonly used as they are not difficult, can be fairly valid, offer a high level of reliability, are cost free, and require only a couple minutes of time to perform.

RMR Prediction Equations
Scientifically validated RMR prediction equations typically use a combination of weight, height, age, sex, and/or lean body mass to estimate daily caloric expenditure at rest. Some are listed in our TDEE Calculator.8,10,11 Simply input your height, weight, and age and the calculator will show your results (please reach out to an ITC coach if you need help)!

Physical Activity Levels (Activity Factors)
These resting metabolic rate estimations are then multiplied by a physical activity level (PAL) to help estimate how many more calories the individual’s average activity requires.10,11
It’s easy to see how athletes’ bodies require so much more energy to run, and these numbers are simply just for maintenance!
When athletes are training for certain adaptations that require an increase in muscle mass, even more calories are needed! Research shows that an increase of 10-15% over estimated maintenance is needed to significantly gain muscle mass.12,13 Any less than this, and nutrition can become a limiting factor.14,15,16

Where To Start: Next Steps?
It is easy to be overwhelmed by this amount of information even though it is just scratching the surface. Outlined below are some great starting steps for taking control of your fueling and optimizing your body to train harder, recover faster, and perform better!

  1. Keep a food journal
    1. Simply track what you eat for a week to a month
    2. It does not have to be super detailed, but be detailed enough to track food content and rough amount (example: not just “burrito” but “Chipotle burrito with [list all burrito fillings]”)
  2. Estimate resting metabolic rate (RMR) and physical activity level (PAL)
    1. Use our calculator to see the full estimation range! TDEE Calculator
    2. Or meet with an ITC coach and go over it together!
  3. Talk with your ITC coach about guidelines for a good starting point
    1. Once you have your food journal of current nutrition and a maintenance calorie estimate, meet with an ITC coach about how nutritional tweaks might help optimize your goals.
  4. Continue to educate yourself on fundamentals of sports nutrition so you can better fuel your body for elite performance
    1. Educating yourself about why you are doing what you are doing for performance can help you understand the ins and outs of sports performance and why certain aspects of nutrition matter for training, recovery, and performance.
    2. See our other articles in this series or others!
    3. Talk to an ITC coach about concepts or questions that you have! We are always here to help.
    4. Seek out other educational materials (books, videos, podcasts, etc…)
      1. Just be careful about where you get your information from; there is a lot of misinformation out there.

References:

  1. Cleveland Clinic. (n.d.). Dietitians vs. nutritionists: What’s the difference?. Health Essentials. https://health.clevelandclinic.org/dietitian-vs-nutritionist
  2. Kreider, R. B., Wilborn, C. D., Taylor, L., Campbell, B., Almada, A. L., Collins, R., Cooke, M., Earnest, C. P., Greenwood, M., Kalman, D. S., Kerksick, C. M., Kleiner, S. M., Leutholtz, B., Lopez, H., Lowerty, M. L., Mendel, R., Smith, A., Spano, M., Wildman, R., Willoughby, D. S., Ziegenfuss, T. N., & Antonio, J. (2010). ISSN exercise & sport nutrition review: Research & recommendations. Journal of the International Society of Sports Nutrition, 7(1). https://doi.org/10.1186/1550-2783-7-7 
  3. Oxford University Press. (n.d.). Calorie. Oxford English Dictionary. https://doi.org/10.1093/OED/7608408568 
  4. US Department of Agriculture. (n.d.). Food and nutrition information center. National Agricultural Library. https://www.nal.usda.gov/programs/fnic#:~:text=Carbohydrates%20provide%204%20calories%20per,provides%209%20calories%20per%20gram 
  5. Osilla, E. V., Safadi, A. O., & Sharma, S. (2022). Calories. StatPearls Publishing. https://www.ncbi.nlm.nih.gov/books/NBK499909/ 
  6. Valdes, C. (2025). Globally calorie availability and the prominence of food in household spending are inversely related. US Department of Agriculture. https://www.ers.usda.gov/data-products/chart-gallery/chart-detail?chartId=58376 
  7. Impact Analytics. (n.d.). Trillions in calorie reduction by 2030: New research from impact analytics. https://www.impactanalytics.co/wp-content/uploads/2024/10/Research-Trillions-in-Calorie-Reduction-by-2030.pdf 
  8. NSCA. (2017). Comparing Metabolic Rate Measurement Methods. https://www.nsca.com/education/articles/kinetic-select/comparing-metabolic-rate-measurement-methods/?srsltid=AfmBOor6hF4dHJsFPnBa7JZU8oeSl2z37gmrVJpipN5pOdIITI11_dD3 
  9. Andy Galpin. (2025, March 5). Jordan Sullivan: Fueling for sports performance & body composition [Video]. YouTube. https://www.youtube.com/watch?v=7hdP5BkF2hI
  10.  Medeiros, D. M., & Wildman, E. C. R. (2022). Advanced human nutrition (5th ed.). Jones & Bartlett Learning.
  11. Journal of Clinical Medicine. (n.d.). Activity factor according to level of activity. https://clinmedjournals.org/articles/jnmdc/jnmdc-2-016table1.html  
  12. Andy Galpin. (2020, December 28). New science of muscle hypertrophy – part 3, eating & training: 55 min phys [Video]. YouTube. https://youtu.be/cw6XPWaEK20?feature=shared
  13. Aragon, A. A., & Schoenfeld, J. B. (2020). Magnitude and composition of the energy surplus for maximizing muscle hypertrophy: Implications for bodybuilding and physique athletes. Strength and Conditioning Journal, 42(5), 79-86. https://journals.lww.com/nsca-scj/fulltext/2020/10000/magnitude_and_composition_of_the_energy_surplus.9.aspx
  14. Wati, I., Kusnanik, N., Wahjuni, E., Samodra, Y., Gandasari, M., & Sofyan, D. (2024). Eat well to the best performance: Calorie intake and eating behavior among athlete: A review. International Journal of Public Health Science, 13(1), 253-259. https://pdfs.semanticscholar.org/33a6/e768d3ce55fd4312b86a366b1366b9729d13.pdf 
  15. Helms, E., Zinn, C., Rowlands, D., & Brown, S. (2013). A systematic review of dietary protein during caloric restriction in resistance trained lean athletes: A case for higher intakes. International Journal of Sport Nutrition and Exercise Metabolism, 24(2), 127-138. https://journals.humankinetics.com/view/journals/ijsnem/24/2/article-p127.xml
  16. Pramuková, B., Szabadosová, V., & Soltésová, A. (2011). Current knowledge about sports nutrition. The Australasian medical journal, 4(3), 107–110. https://doi.org/10.4066/AMJ.2011.520 
  17. Fryar CD, Carroll MD, Afful J. (2020). Prevalence of overweight, obesity, and severe obesity among adults aged 20 and over: United States, 1960–1962 through 2017–2018. NCHS Health E-Stats. https://www.cdc.gov/nchs/data/hestat/obesity-adult-17-18/obesity-adult.htm#1 

In The Core Athlete Inc.

5455 Spine Rd, Boulder, CO, 80301

Here at ITC, we educate athletes on the importance of different lifestyle choices on recovery and performance. This pyramid of recovery concepts provides an overview for how we teach athletes about recovery and how significantly it can affect their performance.

Geno's Story

My son Dante has been training at In The Core since 2019 and my daughter Ava has been training there since 2023.  They are both year-round athletes that put a lot of stress demand on their bodies through their respective sports and consequently they put stress on their minds through school, sports, social life, etc.  With that said, when we found ITC we were drawn to not only the physical athletic training but also the mind/brain work and encompassing everything all into one.  Simply put, training the full body not only for competition but also the life of a teenage student-athlete and the preparation into adult hood.  There are many options in the market if you’re looking to just get bigger, faster, stronger but if you are like us, and you were looking for more than that, ITC is the place to come.
 
The coaching and training aspect of ITC is impeccable.  The details and focus of every session will ensure your athlete has an incredible workout that is tailored to them individually every time they visit.  The brain work and the messages they learn through the training has my kids walk out of ITC sessions a completely different person.  They are more upbeat, energetic, and motivated even though they just performed an intense work out for 45-90 minutes.
 
As a former athlete, it is very evident to see the physical results in their training.  As a parent, I see my children’s growth in their mindset and maturity.  I see them thinking about their futures in ways they never did before, I see their motivation in helping and be a part of the solution, and I see them wanting to serve something higher than themselves.  For me and my family, this means being a complete athlete which is what they receive from the team at ITC.
 
ITC has been a huge blessing for our whole family.  The lifelong friendships and relationships that we have developed and the tools that our children have received are priceless.  We are forever grateful and forever ITC!