Fundamentals of Energy Expenditure

Taylor Carr, MS Sports Nutrition, MS Strength and Conditioning

Energy is something I never seem to have enough of. After I rush to work each morning, I spend 8 hours pushing others to get stronger. Then I come home to make dinner with little motivation. And where does that leave me for my evening training session? At meal time, I am looking for the fastest thing I can possibly cook. So the question is: is my priority to take care and prepare my body to push the limits in the gym or crag or is my priority just simply getting there? Is it fair to make such audacious demands on our body without giving it what it needs to get the job done? Certainly not.

If your only priority is to just make it out to the crag, you may be holding yourself back from actually getting that send you’ve been training so hard for. If you find yourself rushing into the gym, you may be disappointed when you don’t hit the maximum numbers you planned for. While I understand that we are not training or performing at maximum intensity every session, considering energy intake prior to training can be just as critical as the training itself. If you do not intake a proper amount of energy nutrients, how can you expend the level of energy your training requires? 

The energy I’m talking about here is used in our bodies in order to function, move, and live. This energy comes from the carbohydrate, protein, and fat in the food and drink we consume. Energy is measured in kilocalories (kcal) and the amount of stored energy is known as energy density. Different foods have varying amounts of energy. The levels of energy in the foods we eat have a great impact on how we perform while climbing.

Carbohydrates are the main fuel source for climbing because it powers the anaerobic lactate energy system. Different types of climbers may benefit from varying amounts of carbohydrate (45%-75% of overall diet). When you take in carbohydrates, your body stores them as glycogen in the muscles and liver. However, these stores are limited. If you are training at a high intensity, it is critical that these stores are properly fueled prior to exercise. A study by Wroble et al. (2018), suggests that athletes following a low carbohydrate diet may reduce their ability to perform, especially in high intensity activity. If you have limited your carb intake, you are putting yourself at risk for increased fatigue, decreased blood sugar control, digestive issues, hormonal imbalances, and slower recovery time. You may be able to “power through” here and there, but this will not help your recovery process and may lead to injury.


Here are some whole carbohydrates that are beneficial prior to climbing:

  • Sweet potatoes
  • Quinoa
  • Rolled oats
  • Brown rice
  • Vegetables (ALL)
  • Apples
  • Leafy greens


You may be thinking, “Why these? Why not cookies?” Trust me, I could take down a whole sleeve of Oreos myself, but that is not going to get my body ready to train for my project. When we choose a sweet potato over a sweet cookie, our body takes that carbohydrate and converts it to glucose. That glucose is taken directly in the blood, into your cells, and used to produce the true fuel of adenosine triphosphate (ATP). When your body has had its fill of glucose, it is able to then store excess glucose (glycogen) for later use. This can be important for those climbers going to the crag for a long day with multiple efforts on a route. Consuming an extra percentage of carbohydrates will help store glycogen for use throughout the day. When you choose to eat a cookie, however, the sucrose must be broken down before it can be used in the body. Sucrose is a disaccharide consisting of one glucose and one fructose molecule. When the sucrose is split, the glucose increases the amount of fructose that is absorbed. This increases our fat, which is not truly the fuel we need.


You may also be curious about the carbohydrates found in Gatorade. Gatorade is made up of carbohydrates, but it is mostly used for its great electrolytes that will help refuel you after the crag or training session. While it’s not a bad thing to have a sports drink prior to your workout, I would not recommend making a habit of it. Gatorade is beneficial for rehydration, but it does contain a high level of sugar. I recommend saving a sports drink for after your training or climbing session in order to reap the refueling benefits of the electrolytes.


Protein is not typically used for energy, but rather to build muscle and repair tissues. You may wonder then why it is important to still consider our protein intake when it is not beneficial to our energy levels. When we consume the best percentage of protein for our body, it will maintain lean muscle mass and reduce our risk for injury. Consuming protein will also keep your blood glucose levels stable, which will make you feel more energized. Protein percentage for climbers should be between 10 and 30 percent of total calories consumed.


Proteins that will benefit your recovery and performance:

  • Lean meat (typically chicken or fish) or tofu
  • Greek yogurt
  • Broccoli
  • Hard boiled eggs
  • Chickpeas
  • Low fat milk


There are multiple macronutrient calculators online for reference. This may be beneficial to find a starting point in your intake, but I do not recommend strictly following those online sources. The range of protein intake that a calculator will give you will more than likely not be enough for what you need as an active climber. It is important to note that each of us feel better at varying percentages of carbohydrate and protein. You may not be getting enough carbohydrates if you are constantly fatigued, finding it difficult to concentrate, you stay bloated, or have mood swings. For protein, it is important to take notice of how much muscle you are maintaining, how strong you feel overall, and how often you are becoming injured.


If you are wondering why I have not touched on fat (a very important macronutrient), it is because it holds a less crucial role in increasing energy. Most of us are either going to the gym to train, hitting the boulder field, or going out to climb single pitch sport at the crag. These high intensity activities for a shorter duration are going to primarily use your carbohydrate for fuel. Fat will be utilized during low intensity and long duration climbing. Fat can be beneficial for fuel when you are wanting to go out for a day of multipitch sport climbing. Increasing your fat intake for days like these will help increase your energy density rate. However, it is important to note that it is simply more efficient to use carbohydrate as a fuel source because it already takes less energy to turn into fuel (ATP) than for fat to be used as energy.


If you are not already pursuing the advice of a sports nutritionist, feel free to play around with different percentages of these macronutrients. Truly listen to what your body is telling you and go with what works. Make this an added section alongside your training program. Taking the extra bit of time to plan your energy intake will make a drastic difference in your performance levels and overall wellbeing. 

Wroble, K.A., Trobble, M.N., Schweitzer, G.G., Rahman, R.S., Kelly, P.V., Weiss, E.P. (2018). Low-carbohydrate, ketogenic diet impairs anaerobic exercise performance in exercise-trained women and men: a randomized-sequence crossover trial. Journal of Sports Medicine and Physical Fitness, 59(4), 600-607. DOI: 10.23736/s0022-4707.18.08318-4

Leave a Comment