Train Your Gut, Train Your Performance: Why Your Stomach Needs Practice Too

Train Your Gut, Train Your Performance: Why Your Stomach Needs Practice Too

Train Your Gut, Train Your Performance: Why Your Stomach Needs Practice Too

When athletes think about training, they usually focus on building stronger legs, a healthier heart, or improving endurance. But there's another part of your body that also needs training if you're preparing for longer events—your digestive system.

Whether you're running a marathon, tackling an ultra, riding a century, or heading out on an all-day hike, your ability to absorb carbohydrates and fluids can have a significant impact on your performance.

Just like your muscles adapt to training, so can your gut.

What is gut training?

Gut training is the process of teaching your digestive system to comfortably absorb carbohydrates and fluids while you're exercising.

For shorter sessions, this isn't usually a concern. But once your activity extends beyond 90 minutes, your body begins relying more heavily on the fuel you consume during exercise.

If your stomach isn't accustomed to processing food while you're moving, you may experience:

  • Bloating
  • Stomach cramps
  • Nausea
  • Sloshing
  • Feeling "too full"
  • Needing to slow down or stop eating altogether

The good news? Like any part of training, this can improve with practice.

Why does gut training matter?

Your muscles need carbohydrates to perform, but they can only use what your digestive system is able to absorb.

Research has shown that athletes who regularly practise consuming carbohydrates during training often experience:

  • Better carbohydrate absorption
  • Improved tolerance of larger carbohydrate intakes
  • Fewer gastrointestinal issues during competition
  • More consistent energy levels over long events

In other words, you're not just training your legs to go further—you're training your body to fuel those legs more effectively.

Why you should never try something new on race day

It's one of the oldest pieces of endurance advice, and for good reason.

Race day isn't the time to discover:

  • You don't like a particular flavour.
  • A gel is too thick for your preference.
  • You need more water with your nutrition.
  • Your stomach doesn't tolerate eating every 20 minutes.

Training gives you the opportunity to experiment and develop a strategy that works for you before it really matters.

How to start training your gut

The best approach is gradual.

Start with shorter sessions

Begin using the same GU products you'll rely on during longer events.

Even on a 60–90 minute session, practise taking carbohydrates at planned intervals so eating during exercise becomes routine.

Increase carbohydrate intake slowly

Rather than jumping straight to high hourly carbohydrate targets, increase your intake over several weeks.

This allows your digestive system time to adapt while helping you identify what works best for your body.

Practise your timing

One of the most common mistakes is waiting until you feel hungry or low on energy.

Instead, practise eating to a schedule.

For many endurance athletes, this means consuming carbohydrates every 20–30 minutes throughout longer sessions. Our Gels are formulated with 21-23g of carbs per serving to perfectly hit this 30 minute interval with the right amount of carbs for optimal absorption. 

Using a watch reminder or bike computer alert can make this much easier.

Use the products you'll race with

Consistency is important.

Training with the same nutrition you'll use during an event helps eliminate surprises and builds confidence in your fuelling plan.

Depending on your preference, that could include:

Every athlete is different, so finding the combination that suits you is part of the training process.

Train your hydration too

Gut training isn't just about carbohydrates.

Learning how much fluid you need—and when—is equally important.

Drinking too little can contribute to dehydration, while drinking excessively can lead to discomfort and dilute important electrolytes.

Long training sessions provide the perfect opportunity to understand your own sweat rate and hydration needs in different conditions.

Signs your gut is adapting

Like any training adaptation, progress takes time.

Positive signs include:

  • Less bloating during exercise
  • Reduced nausea
  • Feeling comfortable eating while moving
  • More stable energy levels
  • Greater confidence in your race nutrition plan
  • Being able to maintain regular fuelling without discomfort

Common gut training mistakes

Even experienced athletes can make mistakes that affect their nutrition strategy.

Avoid these common pitfalls:

  • Waiting until race day to test nutrition.
  • Eating only when you feel hungry.
  • Trying to consume too much carbohydrate too quickly.
  • Forgetting to practise hydration alongside fuelling.
  • Using products inconsistently throughout training.

Your gut is part of your training plan

Training for endurance events isn't just about building fitness—it's about preparing your entire body for the demands of the day.

Your muscles, heart and lungs all adapt through consistent practice. Your digestive system is no different.

By gradually practising your fuelling strategy throughout training, you'll improve your confidence, reduce the risk of gastrointestinal issues, and give your body the best opportunity to make use of the nutrition you're carrying.

Come race day, your stomach should be just as prepared as your legs.

Try different products, timings, quantities, and explore what's optimal for you! 

Check out our product range here!

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