Gut Training for Endurance Events

The gut plays a crucial role in athletic performance, especially during endurance events. Gastrointestinal issues—such as bloating, nausea, and cramps—are some of the most common challenges athletes face during prolonged exercise. These symptoms can significantly affect performance, therefore, the goal is to reduce their impact.

In this article, we’ll explore the causes of gastrointestinal issues and discuss how adding gut training to your routine can enhance your performance.

Why Do We Experience Gastrointestinal Issues During Exercise?

Gut issues during exercise are primarily caused by the body’s physiological response to exercise.

As we exercise, blood is redirected away from the gut and toward the muscles and skin, which helps fuel muscle activity and regulate body temperature.

This reduced blood flow to the gut can lead to discomfort and even damage to the gut lining. Additionally, the stress of exercise can impair gut function, slowing down digestion and nutrient absorption, making it more difficult to take in carbohydrates during physical activity.

Several factors can exacerbate these issues, including:

• Exercise intensity
• Exercise duration
• Environmental conditions
• Hydration levels
• Feeding tolerance

Why Should I Train My Gut?

The gastrointestinal system is adaptable, meaning we can train it to function optimally for endurance exercise. Gut training focuses on improving gastric emptying (how quickly food leaves the stomach), enhancing intestinal absorption (how efficiently nutrients are absorbed), and increasing stomach comfort. By improving these areas, athletes can better tolerate higher carbohydrate intake, reduce the severity of gastrointestinal issues, and ultimately improve performance.

How Do I Train My Gut?

Gut training can be broken down into four key areas:

1. Trialing Supplement Products
2. Increasing Carbohydrate Intake
3. Increasing Fluid Volume
4. Mimicking Race Day Nutrition

To maximise the benefits of gut training, it's best to start 8–12 weeks before your event, which typically aligns with the later stages of your endurance training block. Here’s how you can incorporate these elements into your training:

1) Trialing Supplement Products

Start by experimenting with various carbohydrate supplements to see what works best for your stomach. A great way to do this is by using an energy gel selection box, which allows you to sample different products to find the one that suits your gut the most.

Once you’ve identified the supplements that work for you, stick with them throughout your training to avoid any negative reactions from introducing new products too late in the process.

2) Increasing Carbohydrate Intake

Begin by consuming 20g of carbohydrates per hour during your long runs and gradually increase your intake by 10g each week or until the previous week feels comfortable.

For activities lasting 1-2.5 hours, aim for 60g of carbohydrates per hour.

For events lasting over 2.5 hours, target a range of 60–120g per hour.

Keep in mind that it may take some time to adapt to higher carbohydrate levels, especially if you're not accustomed to fueling during exercise.

3) Increasing Fluid Volume

Exercising in hot conditions naturally increases your fluid needs. Large volumes of fluids can sometimes cause discomfort, but training with higher fluid intakes will help your stomach adapt to these conditions.

Gradually increase your fluid intake during long training sessions to help your gut adjust to the increased volume, reducing discomfort when it matters most.

4) Mimicking Race Day Nutrition

As your long runs increase in distance, it’s essential to begin mimicking race day nutrition. This will allow you to assess how your chosen supplements and fueling strategies feel in your stomach during extended sessions.

By experimenting with race-day nutrition in training, you’ll be able to fine-tune your strategy, identify potential issues, and make adjustments with plenty of time before the event.

Conclusion

Gut training is an essential part of preparing for endurance events. By proactively addressing gastrointestinal issues and training your gut to handle increased carbohydrate intake, fluid volumes, and race-day nutrition, you can minimise discomfort and optimise performance.

Start early, be consistent, and ensure your gut is ready to support you when it counts the most.