Athletes’ Nutrition: It is known that maximum athletic performance is achieved through a balanced diet. In addition to proper nutrition, dietary supplementation during training or competition is important. Especially when exercise lasts longer than one hour.
Athletes’ Nutrition: What to Consume During Training or Competition
Carbohydrates: To avoid quick fatigue.
Fluids: To stay adequately hydrated.
First Goal: Consuming Carbohydrates
There are two energy stores in your body: fat stores and glycogen stores. Glycogen stores, in the form of muscle glycogen, are the first and easiest source of energy used during exercise. Essentially, the duration and intensity of exercise determine which form of energy (fat or muscle glycogen) should be utilized more and which less. As the intensity of exercise increases, the body uses more carbohydrates and less fat.
Unfortunately, unlike fat stores, muscle glycogen can be easily depleted. Specifically, when the competition or exercise lasts more than 90 minutes, glycogen stores are insufficient. If they are depleted, fatigue quickly sets in, negatively impacting athletic performance.
Second Goal: Proper Hydration
Proper hydration during exercise is important to prevent two dangerous conditions for the body: dehydration and hyponatremia. Dehydration is mainly caused by lower fluid intake or increased sweat loss. Hyponatremia is primarily caused by excessive water intake or excessive sodium loss through sweat. Additionally, weather conditions (cold, heat, humidity) in the location of the sporting event can affect your hydration levels. Besides confusion, weakness, cramps, and fainting, both of these conditions can adversely affect your athletic performance.
Achieving the Goals
The recommendations of the American College of Sports Medicine suggest consuming 30-60 grams of carbohydrates (or 0.7 grams per kilogram of body weight per hour) along with 400-800 ml of fluids for every hour of exercise. Additionally, it is recommended to replenish electrolytes (sodium and potassium) lost through sweat.
Ideally, the following are considered for consumption during exercise:
Energy gels: Sports gels contain approximately 20-25 grams of carbohydrates per serving, and some also provide electrolytes, caffeine, and/or vitamins. Consume 1-2 servings per hour with 400-800 ml of water.
Energy bars: Sports bars contain approximately 40-60 grams of carbohydrates and 6-20 grams of protein per serving. Choose those with a high carbohydrate content and low levels of protein, fat, and dietary fibre to avoid gastrointestinal disturbances.
Sports drinks: Sports drinks provide carbohydrates, electrolytes, and fluids to prevent excessive fluid loss and fatigue. They are the most suitable choice, especially in environments with heat and humidity. Choose isotonic drinks that contain carbohydrates in a 6-8% concentration. This is because they do not cause gastrointestinal disturbances while providing the appropriate amount of carbohydrates and electrolytes to the body.
In addition to the above, you can consume salted nuts, dried fruits, raisins, bananas, or honey, as long as you are sure they will not cause gastrointestinal disturbances. It is essential to conduct tests during training to determine what suits you best and what helps you the most.
The exact recommendations for carbohydrates and fluids depend on the intensity and duration of the sport, as well as the weather conditions prevailing in the location of the competition.
It is best to receive personalized dietary advice, so you know exactly your needs in terms of nutrients, fluids, and electrolytes. Before, during, and after training or competition. This way, you will enhance your endurance, improve your athletic performance, and ultimately enjoy the competition.
By Maria Perperidi, Clinical Dietitian-Nutritionist, M.Sc., for medNutrition.gr
References:
Position of the American Dietetic Association. Dieticians of Canada, and the American College of Sports Medicine: Nutrition and Athletic Performance, J Am Diet Assoc. 2009; 109:509-527. Sawka MN, Burke LM, Eichner ER, Maughan RJ, Montain SJ, Stachenfeld NS. American College of Sports Medicine position stand. Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-90. Jeukendrup A. Nutrition for endurance sports: marathon, triathlon, road cycling. J Sports Sci. 29(S1); 2011: S91-S99. SCAN, website, Sports, Cardiovascular and Wellness Nutrition, a dietetic practice group of the Academy of Nutrition and Dietetics. Nutrition Info, Sports Nutrition Fact Sheets: A Trusted Resource, Sport Foods
