In sport, carbohydrates are essential for maintaining strenuous activity over longer periods of time. The amount of carbohydrates and how best to consume them depends on several factors. Here is an overview.

The metabolisation of carbohydrates and fatty acids is particularly important during exercise. However, converting fatty acids into energy takes time and requires oxygen. This means that during anaerobic physical activity (‘without oxygen’) such as during a 400 m or 800 m sprint, it is almost impossible for our bodies to convert fatty acids into energy. This is why the metabolisation of carbohydrates is extremely relevant in most sports.

But how many carbohydrates do we actually need, and how much is too much? Here are the 5 key factors.

1.    Duration and intensity

• For shorter competitions (30 to 60 min), carbohydrates aren’t required during the race. For longer runs of easy to moderate intensity, it's a good idea to consume 30 to 60 g of carbohydrates per hour.
• For longer competitions, such as marathons or bike marathons, it is recommended to consume 60 to 90 g of carbohydrates per hour. Bear in mind: if you want to consume more than 60 g per hour, the carbohydrates should be consumed in both glucose (e.g. maltodextrin) and fructose form. This combination lets you achieve maximum absorption by the digestive system.
• During easy or shorter training sessions, it is not always necessary to consume the same amount of carbohydrates as during a competition. Exception: a long, high-intensity session or a session simulating a competition. In this case, it is a good idea to test any competition nutrition at a similar intensity and in the same quantity.

2.    Nutrition before training and planned metabolism

• If you want to maximise your metabolism, you should typically minimise your carbohydrate intake before the session – and even several days beforehand if need be. Meanwhile, you should increase your fat intake to avoid energy deficits. No carbohydrates, or small amounts at most, are typically consumed during the session. This is a training measure that is often used by Ironman and ultra-endurance athletes.
• However, if the training goal is to achieve maximum training quality or performance – with a strenuous interval session in preparation for a 10 km or half marathon race, for example – carbohydrates are to be consumed before and – depending on the length – during the session. This guarantees a fast supply of energy.
• The amount of energy consumed before training has a significant impact on training nutrition as well. If you train twice a day or early in the morning on an empty stomach, it will be almost impossible to complete the training with full glycogen reserves. Training nutrition is therefore important.

3.    Type of sport

• The type of sport also plays a key role when choosing a nutritional strategy. For ultra-endurance competitions (e.g. Ironman, trail running), the longer duration has a greater impact on fat burning. This also needs to be practised.
• Another factor relating to the type of sport is the impact on the digestive system. It appears to be more difficult for runners to absorb a high quantity of carbohydrates per hour as the constant shaking of the digestive system affects its efficiency. In cycling, by contrast, records show that up to 120 g of carbohydrates can be consumed per hour during intensive one-day races.
• It is unclear how much of this is actually digested or consumed. For running sports, it is difficult to metabolise high quantities of carbohydrates during road runs, while swimmers also experience frequent digestive issues. The horizontal position in the water and swallowing water and air are just two of the possible reasons.

4.    Food stations

• The nutrition options during a competition are key to the right carbohydrate amount. It’s therefore worth checking out the food stops and products carefully beforehand and testing them in advance.
• This is particularly important during sports such as trail running or ultra-endurance events where nutrition is provided along the route.
• In training, you can take your own source of nutrition with you (running backpack). When planning the route, you might also want to look out for drinking water spots.

5.    Individual tolerance

• This point is crucial – and hugely personal. You need to be able to tolerate what you consume as otherwise this will affect your performance. You need to test your personal tolerability to the products used.
• Their form (solid or liquid) and flavour also play a role. The body's carbohydrate intake needs to be practised as well. After all, what lands in your stomach or intestines will take a while to be absorbed by your body and muscles!

Longer needs more