Fueling the body for superior performance by Stephanie Karl

Stephanie is Sports Nutritionist at UPANDRUNNING.

Optimizing dietary intake for sports competitors follows general guidelines with fueling requirements varying due to the individual’s energy expenditure, metabolism, state of health, different sports, weight, environmental temperature etc. Like all nutrition advice, evidence- based sports nutrition is important. Optimal nutrition is central to maximum performance and lack of fuel, hydration and electrolyte balance can limit potential. The body uses several energy systems to provide for fuel needs. During training and with the help of diet, adaptations can be made to make the body use fat and therefore preserve carbohydrates for the final stages of demand.

One energy system uses carbohydrates and fat while another relies totally on carbohydrates. As work intensity increases, carbohydrates become the main fuel and at maximum intensity, carbohydrates are the principle fuel the body can use. During continued exercise, such as marathon swimming and running, cycling, and triathlons, the need for carbs and fats fluctuate depending on level of fitness, intensity of exercise, duration and food and drink consumed before and during the exercise. To truly understand the way your body uses fuels under pressure we conduct VO2 max and lactate testing.

WhatsApp Image 2021 03 20 at 09.57.57


A diet rich in carbohydrates is the main dietary focus of endurance sports as well as intermittent high, intensity sports such as football, basketball and tennis. Maximizing carbohydrate storage as glycogen in the liver and muscle, benefits performance and delays the onset of fatigue. Glycogen and circulating carbohydrate is generally well catered for in sports lasting under 90 minutes, but anything more will start to deplete storage, potentially make carbohydrate ingestion less effective and switch the system into fat oxidation reducing exercise intensity and the opportunity to finish well.

Recommended Intake of Carbohydrates – depending upon the training routine, athletes should consume anywhere from 3-12 grams of carbohydrates per kilogram of bodyweight throughout the day. This percentage is only a guideline for estimating carbohydrate needs as many factors need to be considered and it is a very wide range. Another calculation is meeting carbohydrate needs for exercise by adding between 1.5-1.8g/minute during exercise. https:// pubmed.ncbi.nlm.nih.gov/23846824/. That equates to 90g plus per hour but again can vary according to intensity, weight, metabolism etc. It does act as a guide for the athlete to trial how this can be done comfortably. Depending upon the length and type of training sessions, an athlete’s carbohydrate intake should adjust, with longer times and more intense trainings reflecting the higher number of grams needed. Working out the pattern for carbohydrate intake is also personal as the tolerance of taking fast acting gels, or energy drinks can become overpowering and uncomfortable in the final stages if a food item has not been introduced at some earlier stage.


go to the UPANDRUNNING website

Posted on 12th Dec 2021