Hitting the gym, pounding the pavement, or enjoying a bit of yoga should leave you feeling better than you started. You’re looking after your body. It feels almost unfair when you’re hit with a sudden case of heartburn after you’ve finished.

But exercise-related heartburn isn’t uncommon. If you’ve ever noticed this pattern, it’s real, and it’s something you can fix. Often, it comes down to exercise selection, form, and a few other factors.

Below, we cover everything you need to know about acid reflux from exercise: why it occurs, what to do, and when it might be something more serious.

Why Does Heartburn Strike During a Workout?

We usually blame heartburn on what we eat or lying down too soon after meals. And while fatty or acidic foods are common culprits, they’re far from the whole story.

Exercise can trigger reflux for different reasons. Many workouts involve bending, crunching, or inverted positions. During strength training, for instance, you naturally brace your core, which increases pressure in your abdomen. That pressure can squeeze the stomach and push acid up into the oesophagus.

Running works in a similar way. The repeated jostling and subtle tightening of the abdominal muscles increase internal pressure, making acid backflow more likely.

Hydration matters too. Being even mildly dehydrated can make reflux more noticeable, especially if it slows digestion or irritates the stomach. Certain pre-workout drinks or protein shakes may also stimulate acid production.

Common Workouts That Cause Heartburn

Not all exercises cause heartburn. Light stretching, swimming, or team sports are gentler on the stomach. The most common heartburn-triggering exercises include:

• Running and other high-impact cardio, where constant jostling can push acid upward

• HIIT workouts, which combine high intensity exercises with lots of bending and bracing

• Core-heavy routines, like sit-ups and planks, that tighten the abdominal muscles

• Cycling in a hunched position, which compresses the stomach

• Yoga poses that fold or invert the body, such as forward bends or downward-facing positions

Pre-Workout Tips to Prevent Exercise Heartburn

The solution to exercise-induced heartburn isn’t less exercise. Instead, it’s about the right preparation.

Always leave plenty of time between eating and exercising. Around 1 ½ hours should be long enough, but if you still notice symptoms, try 2-3 hours. You’ll also want to drink plenty of water during and throughout the exercise.

What you wear matters too. Tight clothes (especially waistbands) add to the pressure in your abdomen. Wear loose-fitting clothing to give your stomach freedom to move.

What to Eat (and Avoid) Before Exercising

If you’re going to eat something before exercising, avoid trigger foods. Avoid anything heavy, fatty, or acidic. It’s best to pick something that’s light, preferably with complex carbs and lean protein.

Oats are a popular choice, as is chicken breast, depending on your objectives. You can pair chicken with rice, broccoli, carrots, or other easy-to-digest foods that aren’t going to trigger reflux.

Limit your intake of spicy meals, citrus, coffee, chocolate, or fizzy drinks.

During-Workout Adjustments That Help

For some people, it’s not what they’re doing but how they’re doing it. Often, they’re grinding through exercises or pushing too hard. The stomach never gets a moment to settle.

A smarter approach is to slow the intensity, swap exercises, and practice breathing techniques that prevent bracing without you realising it.

If you’re running, that could mean switching to an interval model: fast periods and slower periods. Or if you’re lifting weights, alternate between intense and less intense exercises. You’ll also want to consider posture. Avoid bending too much or compressing the stomach.

After-Workout Habits to Reduce Reflux

Give yourself time to reset after your workout.

This could be as simple as a short walk or a gentle stretch. Delay lying flat until you’ve fully settled. Drink plenty of water, but don’t overfill the stomach. Overfilling can have the reverse effect.

It’s sensible to give yourself 30 mins to 1 hour of recovery before you start eating. That’s enough time for your stomach to stop being so reactive.

When Heartburn After Exercise Could Signal Something Else

Heartburn isn’t always exercise. If you start noticing regular symptoms, experience nighttime reflux, or have trouble swallowing, it’s time to speak to a doctor.

Don’t ignore these symptoms, especially if they’re worsening.

The Functional Gut Clinic offers specialist testing and personalised assessment for people struggling with heartburn. We can confirm if you’re experiencing acid reflux and help diagnose the cause. If your symptoms just won’t go away, get in touch with our team. It’s the first step to becoming symptom-free.

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