Whether you are an ambitious amateur or a professional athlete, strong muscles and bones are essential for an athlete. However, it is less obvious that the gastrointestinal system also plays a crucial role in achieving peak performance. Tom Dumoulin can tell us about this after his well-known intestinal problems in the 2017 Giro d'Italia. However, there will be many others who have had to abandon a training session or competition due to stomach or intestinal problems. What causes these kinds of problems? Could you be eating too much? Or choosing the wrong products? And above all: are your stomach and intestines sufficiently trained to handle the quantities and specific bars, gels or sports drinks that you plan to use during the moment suprême?
In summary:
- Gastrointestinal complaints during exercise can have various causes. They may be related to the composition of the last meal before the start of the exercise, or the timing of food intake prior to the exercise.
- A proper competition nutrition plan with the right sports nutrition products can also greatly reduce the risk of gastrointestinal complaints.
- In order to tolerate higher carbohydrate and fluid intake during exercise, it is crucial to regularly train a competition nutrition plan. The gastrointestinal system is very trainable, so you can reduce the risk of complaints to an absolute minimum.
- This stomach/intestinal training is best carried out over a period of 6 to 10 weeks in the run-up to an important goal. In this period, you gradually increase your intake to the intended carbohydrate target (e.g. 60, 90 or 120 grams per hour) via products that you also plan to use during the actual competition.
The influence of exercise on digestion
Stomach or intestinal complaints during exercise can have various causes. For example, it may be because a meal was eaten too close to the start of exercise. During exercise, the need for blood in the muscles increases dramatically in order to supply them with oxygen and energy. This automatically means that blood circulation to other organs is reduced, which means that the stomach and intestines also receive less oxygen-rich blood. The more intensive the exercise, the more blood must be directed to the muscles. Reduced blood flow to these organs slows down and hinders the digestion and absorption of a meal or snack. The up and down shaking of the various organs also increases the chance of abdominal pain during exercise. For this reason, runners (whose upper body moves relatively a lot) are much more likely to suffer from complaints such as bloating, gas, belching, abdominal cramps or diarrhoea.
Choose easily digestible meals and pay attention to timing
It is therefore advisable to choose an easily digestible meal prior to a training session or competition. You can do this by choosing carbohydrate-rich products that contain relatively little fat and fibre. These two nutrients in particular slow down the digestion and absorption of a meal. Therefore, choose white rice or pasta with a light sauce and a limited amount of vegetables, or white bread with some jam, honey or apple syrup. Also be sparing with the amount of protein-rich products (meat, fish, eggs, dairy, legumes, etc.). In addition to the composition of this meal, also pay attention to the timing of ingestion. Digesting a wholesome meal takes at least 2 to 3 hours, so make sure you leave enough time between your last meal and the start of your training. Also bear in mind that some people will need a little longer to avoid experiencing any discomfort. If you only have a small snack before exercising, try to have it about an hour before you start.
Train your gastrointestinal system for maximum carbohydrate absorption
It is no longer a secret that the correct intake of carbohydrates and fluids during a long endurance exercise is of great importance for good performance. In the previous blogs you have been able to read which carbohydrates are most suitable during your exercise, and also how much you need of them to perform optimally. For top performance in the longest and most strenuous efforts, very high carbohydrate intakes are necessary: up to 90 to 120 grams per hour. However, no one is immediately able to absorb these amounts hour after hour without any problems in the body, especially not during strenuous exercise. Fortunately, the gastrointestinal system, like our muscles, for example, is highly trainable and we can therefore improve our ability to absorb all necessary nutrients.
Optimal nutritional choices during training and competitions
To make this even easier, choose products that can be digested quickly and easily during your training or competition. This can be achieved with solid (e.g. energy bars) or liquid foods (sports drinks and energy gels): the combination of products that works best for you is mainly a matter of personal preference. Liquid products only contain carbohydrates that can be absorbed quickly and a small amount of salt. This puts minimal strain on the stomach and intestines, but at the same time does not leave you feeling full. That is why sports drinks and energy gels are particularly recommended during the most intensive efforts and during sports where there is a high risk of stomach/intestinal complaints anyway (such as running). Energy bars provide energy gradually and make you feel fuller in the stomach. This can be a pleasant choice, especially during light training sessions. It is even more important to look for the combination of products that you like best and tolerate best.
Optimise your performance
To improve your ability to absorb large amounts of carbohydrates and fluids, which is essential for top performance, it is very important to regularly train your competition nutrition plan. By doing this regularly, not only does the tolerance of your stomach and intestines increase (meaning you no longer experience any problems), but it also improves the speed at which the sports nutrition passes through your stomach and increases absorption in the intestines. Various scientific studies show that the transport systems on the intestinal wall that are responsible for the absorption of carbohydrates (glucose and fructose) increase in number when a diet rich in carbohydrates is consumed over a longer period of time. This effectively means more energy enters the body and the muscles also become better at using larger amounts of carbohydrates as an energy source. All these steps ultimately lead to a direct increase in performance.
Train once a week with a high carbohydrate intake
Specifically, it is therefore advisable to start training your stomach and intestines for a period of 6 to 10 weeks in the run-up to an important event. You can do this by achieving a high carbohydrate intake once a week through products that you also want to take during your actual competition. Try to do this in one of the longest training sessions of the week and/or the training session with the most competition-specific intensity. Do not immediately aim for the maximum intake (for example 90 or 120 grams of carbohydrates per hour), but build up gradually week after week (for example, 5 or 10 grams of carbohydrates per hour extra each week). Don't forget to also include the other aspects of your competition nutrition plan (such as adequate fluid intake).
