Running Induced Nausea: Why it Occurs and How to Prevent It

Yesterday I had one of my best long runs in a long time. I felt strong and in my element. Everything was spot on. Unfortunately, as soon as I got home, I felt super nauseous. Instead of enjoying my post-run ritual, I spent it doubled over the toilet, spilling my guts.

Right on the spot, I knew something was amiss. I did a quick Google search, and it turned out that a mix of sushi (a bad pre-run meal for me), humidity, and harder-than-usual long run were likely what made my stomach act out.

To save you from similar future trouble, I decided to write a full post on it. Here are the guidelines you need to prevent yourself from feeling sick—or even vomiting—during and after a run.

Running-Induced Nausea Demystified

Running-induced nausea is a real thing. It can happen to anyone—and can get in the way of the post-run bliss you should be enjoying—just as happened to me.

Running-induced nausea is a feeling of sickness or vomiting that strikes during a run or shortly after a run. The condition can be a symptom of fatigue, eating the wrong foods, underlying illness, and more.

What’s Likely Causing it?

There are a multitude of things that can cause nausea (exercise-induced or not), but they all fall under one of two general categories: physiological or mechanical.

The physiological causes primarily involve blood flow. When running, up to 80 percent of blood flow gets diverted from the GI tract to the working skeletal muscles and skin. When this happens, digestion drastically slows down, and that, in turn, may induce discomfort, even triggering a vomiting or nausea response. This is especially true if you had a meal or snack too close to exercise time.

The other major culprit is a mechanical response. The simple up and down jostling of the body while running stirs the bowels and manhandles the intestines (and whatever’s in them), which, in turn, can provoke nausea. Again, this is made worse by having a full meal close to workout time.

There are other things that can bring on nausea while exercising. These include:

  • Low blood sugar
  • Running too intensely
  • Irritable bowel syndrome
  • Dehydration
  • Skipping the cool-down.
  • Having a history of GERD disease
  • Climate conditions

How to Prevent Running-Induced Nausea

The blustery feeling in your stomach is preventable if you take the right precautions. The following are your best bets.

1. Mind Your Pre-Run Meal

To avoid a sluggish, nauseating feeling during a run, I strongly recommend planning your session for two to three hours after a regular meal, or longer if you’re prone to the condition. That’s your first step.

If you run in the morning, have a small pre-run snack, but if you’re nausea prone make it a rule not to eat within an hour of starting your session.  Check these healthy snacks here.

Opt for good sources of complex carbs and healthy proteins that are quick to digest. Banana, oranges, eggs, and fish are all good choices. Also, make sure to experiment with different types of food and the timing of your meals before running to find what works the best for you.

2. Stay Within Your Fitness Level

When you’re overextending past your fitness level, your body reacts by boosting blood flow to your vital organs and skeletal muscles. That’s how you’re able to keep working out for an extended period of time.

Unfortunately, when that happens blood is rushed away from your stomach and sent to your extremities. This, in turn, makes you feel nauseated and sick.

The takeaway is that to ward off running-induced nausea, you need to exercise within your fitness level. If your body is not used to a certain training intensity (like running eight miles at a 6:30-minute pace), don’t go at it full throttle. You’re only going to run your body into the ground.

Instead, keep intensity within your tolerated range. To err on the side of caution, increase your running distance and intensity incrementally. Don’t know how? Simply opt for the 10 percent rule.

Once you’re running for an hour at a conversational pace, add a speedwork session to your weekly routine. For more tips for beginner runners, check the following posts.

3. Hydrate

As you run, you lose water through sweat. The fluid that’s lost must be swiftly replaced. Otherwise, you’re setting the stage for dehydration. When you’re dehydrated your body lacks the key fluids, it needs to optimally perform its normal functions, and this results in a slew of problems, including manifesting as nausea.  Make sure to steadily drink plenty of water before, during and after a run. Here’s the full guide to proper hydration while running.

4. Cool Down

When you stop running abruptly, your heart continues to pump blood to your extremities. This leaves less blood for your brain, which in turn can trigger nausea in some individuals.

I strongly recommend that you invest time into a decent cooldown, even if you’re not prone to post-run nausea. A solid sequence helps redirect blood flow more evenly throughout your body and bring things back to a normal level of function.

Here’s my favorite cool-down sequence.

5. Seek Medical help

If everything fails and your nausea symptoms are only getting worse, you MUST seek medical attention immediately. Your doctor’s visit can help you rule out any underlying issues.


Here you have it. The above guidelines are exactly what you need to prevent nausea while running and exercising. Just make sure to take action on what you’ve just learned. The rest is just detail.

I’d love to hear from you in the comments section if you still have any questions or concerns.

In the meantime thank you for dropping by.

Keep Running Strong

David D.