Your legs aren’t the only thing that needs marathon training. Your stomach needs practice, too.

September is a great time to start figuring out which fuels work for you, how much you can comfortably take in, and when to reach for your next gel. For runners preparing for the Austin Marathon, those small experiments now can make fueling feel familiar when longer training runs arrive.

The goal isn’t to copy someone else’s gel count. It’s to build a marathon fueling strategy you can repeat with confidence.

What Is Gut Training for Runners?

Gut training means practicing eating and drinking during exercise so your digestive system becomes more comfortable handling fuel while you run. It involves gradually introducing carbohydrates, testing products and timing, and repeating the routines that work.

According to the Australian Institute of Sport, practicing carbohydrate intake during training can improve tolerance and help the gut handle fuel more effectively. That doesn’t guarantee a symptom-free marathon, but it gives you a better starting point than opening an unfamiliar gel on race morning.

Think of gut training as another part of your preparation, right alongside pacing, shoes, and long runs.

 

Why Start Your Marathon Fueling Plan in September?

September gives you room to experiment before race-day decisions become urgent. You can test a gel flavor, adjust your breakfast timing, or try a different texture without making your longest training run the testing ground.

It’s also a reminder to account for conditions. A warm Austin morning may feel very different from a cooler fall run. Record the weather alongside your fueling notes so you don’t automatically blame a product for a difficult day.

Start with the runs already in your training plan. You don’t need to add mileage or turn every short, easy run into a fueling workout.

 

How Many Carbs Should You Eat During a Long Run?

For endurance runs lasting roughly 1 to 2.5 hours, general guidance is 30 to 60 grams of carbohydrate per hour. For efforts longer than about 2.5 to 3 hours, some runners may benefit from working toward higher intakes, up to 90 grams per hour, with practice and an individualized plan.

These ranges come from the Australian Institute of Sport’s sports nutrition guidance. They are not a requirement to jump straight to the highest number.

If you’re new to fueling, begin near the lower end during an appropriate long run and assess your comfort. Higher intakes require gradual practice; products combining carbohydrate sources, such as glucose and fructose, can be useful when intake exceeds 60 grams per hour.

Count carbohydrates from everything you consume, not just gels. Two gels containing 25 grams each supply 50 grams of carbohydrate. Add a drink containing 20 grams, and your total becomes 70 grams.

Check labels carefully: an electrolyte drink may contain little or no carbohydrate.

 

How to Practice Gut Training Starting This September

Use this four-stage progression over the coming weeks. Starting late in September? Carry it into October rather than cramming the practice into a few days.

1. Establish a Comfortable Baseline

Choose an easy long run already on your schedule. Eat a familiar, carbohydrate-focused breakfast with enough time to digest, and bring one fuel option to test.

For a run long enough to need fueling, begin early rather than waiting until you feel depleted. Taking your first fuel around 20 to 30 minutes into the run is one practical starting point; the amount and subsequent timing should match your hourly target.

Afterward, note your energy, stomach comfort, and whether eating on the move felt manageable.

2. Repeat Before Increasing

If the first attempt went well, repeat it. One successful run is useful information, but consistency tells you more.

If you experienced discomfort, change one variable at a time. That might mean a smaller portion taken more frequently, a different breakfast timing, or a different gel texture.

Changing your breakfast, gel, drink, and pace all at once makes it difficult to know what helped.

3. Gradually Adjust Your Intake

Once your baseline feels comfortable, increase carbohydrate intake in small steps if your planned run duration and fueling goals call for it.

For example, a runner comfortable at 30 grams per hour might test a modest increase before working toward 60 grams. There is no need to force a weekly increase or chase 90 grams per hour because another runner does.

Keep your running effort and other fueling choices familiar while testing a change.

4. Rehearse the Whole Routine

Practice with the breakfast, fuel storage, products, and timing you expect to use later in training and on race day.

Can you open the packaging while moving? Can you reach your gels without stopping? Do you still like that flavor after multiple servings?

Before depending on on-course fuel, check the current Austin Marathon participant information for available products and locations. Carry what you need to follow your practiced plan.

 

What Are the Best Running Energy Gels?

The best running energy gels are the ones that meet your carbohydrate needs and that you can comfortably consume throughout a run. No single brand or formula works best for everyone.

When comparing options, consider:

• Carbohydrates per serving: Many gels provide about 20 to 30 grams, but serving sizes vary.
• Carbohydrate sources: Glucose-fructose blends can support higher carbohydrate intakes.
• Caffeine content: Check the label and account for coffee or other caffeinated products.
• Texture and flavor: A product you dislike becomes harder to keep taking.
• Water instructions: Most concentrated gels should be taken with water; follow the product directions.
• Packaging: Test whether you can carry, open, and dispose of it comfortably.

Gels aren’t your only option. Chews, carbohydrate-containing drinks, or easy-to-digest foods can also fit a fueling plan. The useful question isn’t “What’s most popular?” It’s “What can I reliably use while running?”

 

How to Eat During Long Runs Without Guessing

Choose an hourly carbohydrate target, check your product labels, and divide your fuel into manageable servings. Use a watch alert if you tend to forget.

For example, a runner who has practiced tolerating 50 grams per hour could use two 25-gram gels per hour, spaced about 30 minutes apart, with water according to the product instructions. That example assumes no additional carbohydrates from drinks or other foods.

Your schedule may look different. Smaller, more frequent servings may feel better than larger portions. What matters is a plan that fits your needs and that you’ve practiced, not a universal “one gel every few miles” rule.

For guidance beyond mid-run fuel, explore our Nutrition Basics for Long-Distance Runners.

 

What If Fueling Upsets Your Stomach?

An uncomfortable run doesn’t automatically mean gels aren’t for you. Consider the whole picture: portion size, concentration, breakfast, caffeine, pace, heat, and hydration.

Follow mixing instructions rather than making drinks extra concentrated. Take gels with water when directed, and avoid forcing excessive fluid just to meet a fueling schedule.

If symptoms begin, ease your effort and reassess rather than pushing through worsening discomfort. Persistent problems deserve help from a sports dietitian or healthcare professional. Severe abdominal pain, bloody stool, or repeated vomiting are not normal training challenges.

Gut training is practice, not a test of how much discomfort you can tolerate.

 

Keep a Simple Long-Run Fueling Log

After each practice run, record your breakfast and its timing, run duration, conditions, products, total carbohydrates, fluids, energy level, and any stomach symptoms.

A useful entry might read: “90-minute easy run, warm morning, familiar breakfast two hours before, 30 grams of carbs per hour, comfortable stomach, steady energy.”

Over time, those notes can help you spot patterns and build a repeatable routine. They also give a sports dietitian useful context if you need help adjusting your plan.

 

Marathon Gut Training FAQs

How long does it take to train your gut for running?

Gut training requires repeated practice over time. Some research has found improvements after about two weeks of structured practice, but that is not a guaranteed timeline. Start early and keep refining your routine throughout your training cycle.

Do I need a gel on every run?

No. Short, easy runs generally don’t require mid-run carbohydrate fueling. Focus your practice on longer runs and workouts where carbohydrate intake supports the session.

Can I use sports drinks instead of gels?

Yes. A carbohydrate-containing sports drink can provide some or all of your planned fuel, depending on its concentration and how much you comfortably drink. Check the label, and don’t drink beyond your fluid needs just to reach a carbohydrate target.

What if I can’t tolerate 60 grams of carbs per hour?

Start with an amount you tolerate and increase gradually when appropriate. Review timing, portion size, products, and running conditions. A sports dietitian can help you work toward a suitable target without repeatedly triggering symptoms.

Should I try a new gel on marathon race day?

Avoid it when possible. Practice with the products and amounts you intend to use, and bring familiar fuel if the on-course options don’t fit your tested plan.

Build Confidence One Long Run at a Time

You don’t need a perfect marathon fueling strategy by the end of September. You need a starting point, a few useful notes, and a willingness to practice.

On your next appropriate long run, choose one fuel, follow a simple schedule, and record how it feels. Repeat what works and adjust what doesn’t.

Your Austin Marathon preparation is about more than covering the distance. It’s about learning how to keep yourself fueled along the way.

 

This article provides general education, not individualized medical or nutrition advice. Consult a registered sports dietitian for a plan tailored to your training and health needs.