Fueling for Athletic Performance
Guest Author: Michael Kenny
Nutrition for athletes can be compared to the fuel you put into your car. The more fuel you put in the further you can go, up to some point. You also need to put the right type of fuel into a car. Adding the wrong fuel can lead to the car breaking down. When we talk about fuel for humans, we are talking about calories (or energy). Calories can be broken down into 3 macronutrients, which are Carbohydrate, Fat and Protein.
Intense exercise results in an initial reduction in performance capacity. Imagine trying to complete the same intense session directly after completing it. Naturally, there would be a reduction in performance compared to the opening session. There is a need for adequate recovery between sessions, with adequate nutrition a pivotal component.
The first and most important consideration is to ensure an athlete has enough calories. As athletes demand more of their bodies via exercise, the energy demands of the athlete exceed that of the average person. Failure to reach the energy demands can lead to weight loss (often muscle mass), illness, psychological and physical symptoms of overtraining and (probably most worrying to the athlete) a reduction in performance.
There are many equations to assist athletes gain estimates of the number of calories required such as the Harris-Benedict equation and Mifflin St Jeor equation. However, most often it is the case that such equations will need to be adjusted following a period of trial and error.
Carbohydrates are the primary source of fuel during high intensity exercise. Research shows the greater the volume of training, the greater the carbohydrate requirement for athletes. An athlete’s carbohydrate intake should predominantly come in the form of complex carbohydrates with a low to moderate glycemic index (e.g. vegetables, whole grains, and legumes). Athletes should also include simple carbohydrates with a high glycemic index specifically pre, during and post exercise.
Fats can often be an overlooked in an athlete’s diet. Fats help move many vitamins around the body (specifically the fat-soluble vitamins- A, D, E and K) and are important for proper physiological functioning. Although fat contains over double the energy compared to carbohydrate per unit, it is slower to be digested, transported, and ultimately converted to energy as it requires more oxygen. As a result, it cannot be used in high intensity exercise like carbohydrates. However, during longer duration, lower intensity exercise such as long-distance running/cycling fat is quite an accessible source of energy.
The body does not want to use protein as a fuel source. Instead, it would prefer to use protein for the repair and rebuilding of muscle which breaks down during exercise. Protein requirements for athletes are greater than the general population. Depending on the mode of exercise and individual goals of an athlete, protein requirement will further vary. Athletes should also focus on protein servings (and distribution throughout the day) and always ensure a high-quality protein source.
Tips to Fuel for Athletic Performance
- 1 – Meet energy requirements: Use one of the calorie calculator equations mentioned above to help you find your caloric maintenance. On rest days/recovery sessions/low intensity days energy requirements may be lower
- 2 – Match carbohydrate intake to training demands: Consume more carbohydrates on days when training demands are high. On rest days/recovery sessions/low intensity days there is a reduced demand for carbohydrate
- 3 – Ensure daily protein requirements are met: Currently, the research suggests that evenly distributed protein doses every 3-4 hours of 0.25 g of a high-quality protein per kg of body weight, or an absolute dose of 20–40 g is sufficient
- 4 – Ensure minimal fat recommendations are met: Currently, the ACSM recommends fat intake for athletes should be between 20-35% of the diet, and should not decrease below 20%.
The food we eat impacts our strength, endurance, training, performance, recovery and well-being. In the words of exercise physiologist Professor Ron Maughan
The winners will, without doubt, be highly talented, highly trained and highly motivated. At one time that would have been enough. But these days it is highly likely that everyone in the race will have these qualities……where everyone else is equal, it is diet that will make the vital difference
About the author
Michael is a Sport Science student intrigued by understanding the variables and key determinants that impact an individual’s (athlete or general population) readiness to perform from both a psychological and a physiological standpoint. His primary areas of research revolve around physical development and the role of nutrition, sleep and stress in physical development. Michael works in multiple strength and conditioning environments from Rugby to Soccer to GAA, and also runs an online coaching service at Synthesize Coaching.
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