Nutrition

The muscle has 2 main energy substrates to make endurance muscle work: fats and sugars. These substrates are stored in order to provide for needs of the muscle when it is activated. During exercise, they are metabolized at the level of mitochondria (the tiny muscle energy centres), where they are transformed to be directly exploitable by muscular fibres.

The muscle always uses an energy mix of fat and sugar, the proportion varying according to the speed of travel and the level of training. Schematically, fats make it possible to go far and sugars to go fast. The brain requires a constant supply of glucose, especially during exercise physical or mental. To avoid "soft blows", it is therefore essential to absorb sugars regularly as soon as the effort is greater than 1 hour.

In Sprint triathlon, the speed is maximum and the effort is short (1h-1h30), so the muscle needs super combustion fuel to produce high power. To do this, it is mainly based on its reserves of intrinsic glycogen (sugars).

In Olympic triathlon (and even more so in LOD), the effort is longer and the speed reduced. The muscle will therefore rely on a higher fat energy mix to produce an effort of medium intensity.

To effectively meet the needs of the body, the use of a food of effort, almost exclusively composed of carbohydrates is highly recommended. Exercise nutrition specialists currently agree that the ideal food must contain a mixture of carbohydrates (glucose, fructose and maltodextrins). This mixture allows a higher rate of muscle oxidation (in the order of 1.5-1.7 g/min) than if one of the 3 types of carbohydrates is consumed in isolation (about 1 g/min). A such difference is related to the fact that it is specific carriers that allow the passage of glucose, fructose and maltodextrins through the digestive membrane, independently of each other. For the moment, the ideal mixture (if there is one) does not have has yet to be determined.

However, it can be assumed that a ratio of 20% glucose / 20% fructose / 60% maltodextrins is a good compromise for long distance triathlon (from B to the IronMan). Consumed at a rate of 60 g per hour of running (in 500-700ml of water), one such mixture will be absorbed quickly without causing digestive "blockage", while ensuring an energy supply and optimal hydration.

Some athletes have a form of intolerance to sugars with a high glycemic index (glucose, dextrose...), which makes them subject to variations in blood sugar during exercise. Hyperinsulinism is often the cause of this problem. In this case, do not hesitate to use much simpler foods (water, fruit, small sandwiches with ham...) or simply to drink only water to avoid diet decreases.

In competition, the effort is always more intense, the stress is higher, the body and the muscles in particular, therefore they need more energy to meet the demands of the effort. It is therefore imperative to adopt appropriate nutrition before and during an effort to competition. And it is very important to train your digestive tract to this new constraint: test various drinks and energy bars and train with them during the weeks that before the race!

• Breakfast: the pre-competition breakfast must be light and digestible. A fruit, a hot drink and a starchy food (bread or cereals) will suffice. It is necessary to always allow sufficient time for digestion between the end of the meal and the beginning of the competition, i.e. 2 to 3 hours. And of course, you should never change your habits on D-Day!

• Swimming / cycling transition: 1/2 energy bar (20g) + 200ml water

• Cycling: The objective is to drink 500 to 750ml of drink per hour of cycling, i.e. about 100ml of energy drink every 10 minutes. Halfway through the race, absorb a bar (25g) or fruit (dried fruit, banana).

• Bike/race transition: 1 energy gel (25g) + 200ml water

• Running: In practice, an half glass of coca or energy drink at each refuelling should allow you to reach the finish line without any problems.