Nutrition and Performance

Why nutrition is so crucial to athletic performance.

Unless we’re talking about building muscle, most body composition goals do not also translate into positive performance outcomes. This is primarily true when in a caloric deficit for weight/fat loss. Depending on the sport and primary energy systems utilized, adequate availability of certain nutrients is necessary to perform well. So if weight and body composition aren’t the main markers of progress, then what is?

Energy Systems

First, it’s important to understand what your body requires to maximize athletic performance. This is determined by the primary energy system that is being utilized for your sport or activity. The reason I say primary energy system is because all energy systems are working simultaneously, however to what degree they are utilized differs. For the purposes of this article, there are three main energy systems, Phosphocreatine (PCr), Anaerobic Glycolysis and Aerobic Oxidation.

Phosphocreatine System

This system is the body’s most rapid way to produce energy. Phosphocreatine, or a phosphate molecule attached to creatine, is the key component in this energy system. This system is the primary driver of short, explosive movements. Phosphocreatine is depleted quite quickly and requires rest and diet in order to replenish stores.

Anaerobic Glycolysis

Anaerobic glycolysis provides energy for the first minutes of high-intensity exercise. Because only a small portion of energy is produced through this system, it cannot be the predominant source of energy for prolonged amounts of time. Anaerobic glycolysis is fueled by glucose (carbs/sugar) from dietary intake or stored glycogen, which is why pre-workout snacks high in carbohydrates are often recommended.

Aerobic Oxidation

Aerobic oxidation breaks down glucose and fat with the involvement of oxygen. This process supplies a larger amount of energy, as long as oxygen and carbohydrates or fat are available. Aerobic oxidation of fats is a slower process than of carbohydrates, however it yields much more energy.

Energy Balance

I’ve mentioned this before, but energy balance means making sure that the energy we consume matches the energy we expend. There are situations and scenarios where being in a calorie deficit or surplus are necessary, but for performance goals, making sure that energy is matched is necessary in order to perform well.

Why do athletes not reach energy needs?

In my experience as a sports dietitian, there are a couple of reasons why athletes are not meeting energy needs. One of those reasons is because they genuinely just do not recognize how much they need to be eating. Sometimes athletes experience a decrease in appetite with intense exercise, paired with stress and being a student, hunger can go out the window. Without being intentional with fueling, this could compound and result in low energy availability. Another reason is because athletes are seeking information from sources who are not credentialed or understand the nuance of individualized nutrition recommendations. Oftentimes, this leads to under eating, whether due to using an online calorie/macronutrient calculator that cannot comprehend their needs, or that the advice they seek out is just plain wrong.

Macronutrients

Macronutrients provide energy, in the form of calories, for our body to produce energy, build muscle, regulate body temperature and so much more. The three macronutrients are carbohydrates, fat and protein, all of which play a role in enhancing performance.

Carbohydrates

Carbohydrates (carbs) are broken down into its simplest form: a sugar called glucose. Glucose is the body and brain’s preferred source of energy. So in order to have the energy to perform in practice or in the weight room, athletes need a lot of energy from carbohydrates. Due to fad diets and misinformation, a lot of athletes are under the assumption that carbs are “bad” and should be minimized. But really that couldn’t be farther from the truth. Typically, increasing carbohydrate intake is one of the first steps that athletes can take to enhance performance.

Protein

Protein is often thought of as only being important for strength athletes because of its role in building muscle. And, while that’s absolutely true, athletes also need protein to repair existing muscles and tissues. And while protein is important, it should only really be about 15-30% of an athlete’s diet. If protein is 50%+ of an athlete’s diet, carbohydrates and fats will probably not be consumed in necessary quantities.

Fat

Fat is important for hormone health, temperature regulation, energy production and more. Similar to carbohydrates, fat is often deemed as “bad” and some athletes tend to under eat this macronutrient and wonder why they suffer from fatigue, hair loss, etc.

Nutrient Timing

Nutrient timing is the calculated placement of macronutrients to leverage their benefits and, as an athlete, get the most out of your food. The most basic way to put this is overall, eat balanced meals but carbs and protein should be prioritized around workouts, with fat and fiber being limited around workouts. Although that’s a watered-down way to explain nutrient timing, it’s a good starting place for athletes just diving into sports nutrition.

Measuring Performance Outcomes

So how do you measure positive performance outcomes? Well, by looking at your progress in training. This could be in the weight room or in practice/competition. Are you lifting more? Do you have more energy in practice? Has your endurance gotten better? Concentration and focus? Essentially we’re taking the focus away from solely looking at weight and body composition, and looking at what has a larger impact on that athlete’s overall health and ability to progress in their sport.

Now, there is obviously a lot more that goes into performance nutrition, but these are a couple of the most basic and important aspects of nutrition that can make an athlete’s performance exponentially better in a short amount of time. Hopefully this was helpful, and as always, I welcome any and all feedback.

-Claire MS, RD