Consuming carbohydrates during an event helps to extend endurance performance in an athlete. It is important to replace both fluids as well as carbohydrates for energy that sustain till the end and improves performance. This will largely depend on the type of exercise, intensity and duration.
Carbohydrates during exercise
Carbohydrate replacement is beneficial in both high intensity short duration exercises and events lasting for more than 1-2 hours. But in the latter type which includes continuous long lasting events like swimming, running, cycling and other sport it is more important.
Carbohydrate replacement during an activity will help to increase time and intensity an athlete and is able to carry out before feeling exhausted. Carbohydrates supplied during an exercise supplies additional fuel for the working muscles thus preventing fatigue and maintaining blood glucose levels. Approximately 30-80 g of carbohydrates is recommended during an event to prevent blood glucose levels to drop and delay fatigue or 0.7 g/kg body weight per hour is recommended to extend endurance performance. This can be obtained from sport drinks, bananas or dried fruits. Some athletes may even prefer diluted fruit juices or suck on hard candies, animal crackers or energy bars that can be easily chewed and digested. Although mixtures of glucose and fructose may seem to be effective, glucose should be the primary fuel yielded from the carbohydrates consumed as fructose seems to be less effective and may cause diarrhea.
Fluid recommendations
Even partial dehydration tends to compromise a performance, thus it is necessary to drink enough fluid and maintain fluid balance. Drink enough fluids (avoid dairy) or in other words water consumption should be around 17 ounces two hours before an exercise and additional 10-15 ounces within 15-30 minutes of an event. Through out competition it is important to remain hydrated, thus drink 6-10 ounces of water or diluted sports drink every 10-20 minutes. Electrolyte replacement drinks can be consumed after one hour of exercising. For intense activity lasting longer than an hour, beverages containing carbohydrates in the concentration of 4-8 % are recommended. Although plain water is considered appropriate for activities lasting less than an hour, 4-8% carbohydrate beverages are also suitable. It is important to replace the electrolytes lost in perspiration, 0.5-0.7 g/l of sodium is recommended for activity lasting longer than an hour. This will also help to increase the palatability of sports drinks and in turn increase fluid consumption. Athletes susceptible to hyponatremia also benefit from added sodium in the fluid replacement beverages. Adequate fluid consumption will also help the body to maintain temperature, blood circulation and proper muscle function.