Ask an endurance athlete, the most important nutrient to fuel them before their event, and most likely they are going to respond “Carbohydrates”. Carbohydrates are the primary source of fuel for the body during any physical activity that we do, and some of the carbohydrates that we eat are also stored as GLYCOGEN in liver and in muscles. And this muscle glycogen is used at the time of intense physical exercise to help an athlete increase endurance.
Carb Loading Or Carbohydrate Loading is a technique used by athletes to enable the body to store more than normal amounts of glycogen in the muscles. This practice helps to increase the endurance of the athlete at the time of the sports event i.e. to sustain the energy needed for an intense activity for a longer duration specially in sport requiring more than 90 minutes of intense activity like long distance marathons, triathlons, swimmers, cross country bike races etc.
During endurance exercise that exceeds 90 minutes, muscle glycogen stores become progressively lower. When they drop to critically low levels, high -intensity exercise cannot be maintained by the runner. In practical terms, the athlete is exhausted and must either stop exercising or drastically reduce the pace. Glycogen depletion may also be a gradual process, occurring over repeated days of heavy training, in which muscle glycogen breakdown exceeds its replacement.
There have been studies showing that how a high carbohydrate diet provided nearly maximal repletion of the muscle glycogen stores after strenuous training.
How much carbohydrate is recommended?
It is recommended that athletes with heavy training should consume a carbohydrate intake of 6-10 g/kg of body weight daily to prevent daily carbohydrate and glycogen depletion. Though the exact amount required depends on the athlete’s total energy expenditure, type of sport, gender, age , and environmental conditions. For example- a 70 kg athlete should consume around 350-700 gm carbohydrate daily.
How should you Carbo Load?
Carb loading can be done from 3-4 days to 7 days prior to the event or practice training. The 7 Day technique usually requires to reduce the intake of carbohydrates to 40-50% of caloric intake with heavy intensity training to deplete all the glycogen stores. This is followed by increasing the carbohydrate intake to 60-70% of caloric intake along with low physical training to ramp up the glycogen stores.
But the most effective technique known for well trained athletes is 3-4 days carb-loading technique. It involves the following steps:
1. Athlete take about 8-10 gms/kg body weight with low levels of exercise to maximize glycogen stores.
2. Duration and intensity of training is tapered down during this time to preserve the glycogen stores that you are creating.
3. A high fluid intake of 1 ml/ calorie consumed is essential simultaneously for successful carb loading.
Important points to remember while Carb Loading
- Carb loading in some cases may lead to heart irregularities, altered blood sugar levels, digestive discomfort, lightheadedness, weakness, weight gain due to the water gain that is inside carbohydrates, therefore carb loading should be well tried and done by the athlete during training sessions.
- Always check with your doctor before starting if you have a pre existing condition.
- Ensure intake of good carbohydrates that also supply with vital vitamins and minerals like whole wheat, corn, bananas, fruits, oats, beans and legumes, milk, potatoes, yoghurt etc.
- Be Sure to drink enough of “non caffeinated” liquids everyday week prior the event.
- Eat at least 6-7 servings of fruits and vegetables each day to get a lot of your carbs as well as much needed vitamins and minerals.
- Include a source of low fat protein at every meal.
- Avoid Junk food , as they do not provide you with the right kind of carbohydrates you should be loading with. Only put nourishing foods in.
The Golden rule of sports Nutrition – nothing new on event day- also applies on carbohydrate loading.
Above information and advice is as per the general norms and guidelines, but if you are an athlete and planning to start carbohydrate loading or you want to maximize your performance for your event, always consult a certified or experienced Sports Nutritionist for a personalized nutrition guidance.