Training Your Stomach | Training The Gut #2

Do you ever feel bloated when consuming a lot of fluids on the bike? This can easily happen during a endurance events in hot conditions. To prevent this and to improve gastric emptying, one can train the stomach. It is an important part of training the gut.

In the previous blog we discussed the importance of training the gut and how it can help to improve your performance. After you have set your race goals and have assessed you current intake, it is time to really start training your gastrointestinal tract.

What is training your stomach?

The stomach plays a significant role in delivering carbohydrates and fluids to the muscles. Since fluid intake can be very high during exercise, the stomach needs to be able to handle large volumes of fluids. Fortunately, the stomach is very flexible and can adapt to ingesting large volumes. This needs to be trained however. By training with high intake volumes, stomach comfort improves. Probably this is because the stomach walls get extended, resulting in more space for the fluid.

Besides being able to tolerate large volumes of fluid, the stomach needs to handle high amounts of carbohydrates during exercise. By increasing the carbohydrate content of your diet the gastric emptying of carbohydrates can be improved. This especially holds when your normal carbohydrate consumption is relatively low.

How to put it into practice

Training the stomach and improving gastric emptying involves two parts that you can train simultaneously. First, to improve stomach comfort you will need to practise the ingestion of large volumes of fluid during a number of training sessions. Start 5 to 10 weeks before competition. During a number of sessions (around 5-6 suffices for most athletes) practise with more fluid intake then you are used to take. By taking larger volumes at once, you get used to the large volume of fluids in your stomach. In the EatMyRide app you can set your desired hourly fluid intake when you are creating a nutrition plan. Also you can keep track of your intake using the Carbohydrate Burn / Intake Balancer for Garmin Edge devices.

In the same period that you train the stomach comfort, you can train to improve the gastric emptying of carbohydrates. You can do this by increasing the carbohydrate content of your diet. So, during a number of training days (up to 10 is advised) focus on a higher carbohydrate intake than usual. More than 5 gram per kg bodyweight is what you should aim for. By tracking both your intake during the training and your meals in the EatMyRide app you get insight into your carbohydrate intake and whether it is sufficient.

Upcoming

The next vital part of training the gut is to train the absorption of carbohydrates. With intakes up to 90-120 grams per hour, it is absolutely crucial to let the body adapt to these high intakes and to train the absorption of carbs. In the next blog we will dive deeper into this. The blog will provide guidelines how you can fit it into your training.

Resources:

• Costa, R. J., Miall, A., Khoo, A., Rauch, C., Snipe, R., Camões-Costa, V., & Gibson, P. (2017). Gut-training: The impact of two weeks repetitive gut-challenge during exercise on gastrointestinal status, glucose availability, fuel kinetics, and running performance. Applied Physiology, Nutrition, and Metabolism, 42(5), 547-557.
• Jeukendrup, A. (2010). Sports Nutrition-From lab to Kitchen. Meyer & Meyer Sport.
• Jeukendrup, A. E. (2017). Training the gut for athletes. Sports Medicine, 47(Suppl 1), 101-110.