Energy Needs For Athletes

As athletes, we need to think about nutrition in a different light than the general population.  Calories in and calories out becomes more than breakfast lunch and dinner.  It has to become a mindset that food is fuel for performance.  The nutrition choices we make directly influence athletic output, so food has to become more than just “healthy choices”.  Athletes must consider a variety of circumstances and in order to optimize their level of play.  In order of significance, athletes have the following considerations.

1) Energy balance

2) Macronutrient ratios

3) Meal Timing

Energy Balance

Many athletes are unaware of the requirements that intense training and sport puts on their bodies and the ability to perform and recover.  Energy balance is defined as a state when energy intake (the sum of energy from food, fluids, and supplement products) equals energy expenditure (the sum of energy expended as basal metabolism, the thermic effect of food, and any voluntary physical activity) (1).

TEE=Total Energy Expenditure

BMR= Basal Metabolic Rate

TEF= Thermic Effect of Food

TEA= Thermic Effect of Activity

TEE=BMR + TEF +TEA

A lack of intake relative to the energy expenditure compromises performance and the benefits associated with training.  With limited energy intake, fat and lean muscle tissue mass will be used by the body for fuel.  Loss of muscle may result in the loss of strength and endurance, and can lead to poor nutrient intake (1).

Exercise is fueled by an integrated series of energy systems which include non-oxidative and aerobic pathways.  Adenosine -triphosphate (ATP) and phosphocreatine provide a rapidly available energy source for muscular contraction, but not sufficient levels to supply the body with energy for longer than 10 seconds.  The anaerobic glycolytic pathway rapidly metabolizes glycogen and becomes the primary pathway that supports high intensity exercises lasting 10-180 seconds (3).

During times of high intensity training or practice, adequate energy needs to be consumed to maintain body weight, maximizing training effect, and maintain health.  Low energy intakes can result in loss of muscle mass, menstrual dysfunction, loss or failure to gain bone density, and an increased risk of injury, fatigue or illness.

Recommendations for athletes’ intakes of energy, macronutrients, vitamins, and minerals are often presented in terms of milligram or gram amounts of nutrients per lb of bodyweight.  The foundations for a training diet for an athlete will not differ that much from current recommendations for the general population.

However, there are a couple of common areas that athletes will need to modify in order to perform at a high level consistently.  Increased fluid intake to cover sweat loss and increased carbohydrates or fats to fuel physical activity.  An increase in protein is also often recommended to help with repair and recovery.

When someone exerts themselves, they damage tissues and use energy.  This breakdown process is what ultimately makes people stronger, more muscular, and more athletic.  However, in the short term this breakdown represents only damage and depletion.  It’s what we do next, nutritionally, that makes a huge difference (2).

Next week we will learn a bit more on Macronutrients and their role in athletic performance and nutrition.

3) https://www.umass.edu/sphhs/sites/default/files/NutritionandAthleticPerformance_TamTran.pdf

4) http://www.humankinetics.com/excerpts/excerpts/the-bodyrsquos-fuel-sources

5) http://www.precisionnutrition.com/all-about-muscle-growth