Nausea After a Workout

Exercise-induced nausea can be caused by your eating schedule, food choices, or the intensity of your sweat session.

Between the hit of endorphins, the post-flow savasana bliss, and the knowledge that you did your body and mind a solid, working out should make you feel good.

But from time to time, while chasing that runner's high or back squat PR, you may suddenly find yourself keeled over, wanting (or worse, needing) to puke.

According to research published in September 2021 in Frontiers in Physiology, this common phenomenon is known as exercise-induced nausea, and it's annoying but normal, undesirable but treatable. Here's what you should know about why it's happening, when you should worry, and what you can do about it.

It Doesn't Mean You're Out of Shape

There's a misconception that getting queasy during or after exercise indicates your overall athleticism. But that's not true. "From beginner exercisers to Olympians or endurance athletes, exercise-induced nausea can affect anyone," Brian Babka, MD, sports medicine specialist and team doctor for Northern Illinois University Athletics, told Health.

"It's not really related to how conditioned you are," Dr. Babka said. A review published in the June 2021 issue of the European Journal of Applied Physiology concluded that training did not decrease exercise-induced nausea.

So if your fitness level isn't the cause of exercise-induced nausea, what is? Authors of the Frontiers in Physiology research explained your digestive system is to blame. More specifically, exercise interferes with the gastrointestinal (GI) tract, resulting in symptoms like nausea, vomiting, and queasiness.

When You Boost Workout Intensity, Your Gut Can Suffer

When you're working out, blood flows to the muscles you're moving and to your hard-working vital organs—like the heart, lungs, and brain. According to a May 2022 review in Sports Medicine, there's less blood distributed to the digestive organs, which puts a pause on the processes that break down food in your stomach.

This process is important from a survival standpoint, Michael Richardson MD, a family physician at One Medical Group in Boston, told Health. "Digesting your food probably comes secondary to running away from a bear," Dr. Richardson pointed out. But in today's world—when we're usually running for fitness or fun—it mainly becomes an unpleasant side effect.

According to Dr. Babka, some workouts command more blood flow away from the GI tract than others. And the more blood diverted, the more intense your symptoms will likely be.

"Due to the size of the muscles in the lower body—like the hamstrings and quads—and the overall volume of a leg-day workout, leg day may leave you more prone to this sensation," Dr. Babka said. High-intensity interval training (HIIT), which involves bursts of vigorous exercise, can also exaggerate this response.

However, it's important to recognize that high-intensity workouts or leg days aren't necessarily better (or worse) than other forms of exercise, said Dr. Babka, or that nausea is the sign of a good workout. High-intensity CrossFitters, endurance athletes, and powerlifters may be at higher risk of exercised-induced nausea, Dr. Babka said, but "it's simply a symptom of lack of blood flow—or an indication that you didn't choose a good pre-workout meal."

Pre-exercise Eating and Drinking Can Affect Nausea

"The largest factor in whether or not you'll experience this nausea is what and when you ate ahead of time," said Dr. Babka. Jim White, RDN, an exercise physiologist and owner of Jim White Fitness and Nutrition Studios in Virginia, agreed.

"Eating too close to your workout won't give your digestive system enough time to start breaking it down, but eating too early may result in your feeling hungry and sluggish," White told Health. "Everybody is different, but eating one to three hours before working out is the suggested window to prevent abdominal discomfort while still fueling your performance."

According to a review published in 2016 in Advanced Biomedical Research, foods high in saturated fat—bacon, French fries, and burgers, for example—take longer to process in the stomach, so the delay in digestion can create a "deadweight" feeling. "Fatty and greasy foods also stimulate your body to secrete bile to help digest the fat," said Dr. Richardson. "This bile can add to the gastric pressure and worsen nausea."

White added that other foods can add to GI distress, "including spicy foods, items containing caffeine, and highly acidic foods."

So what should you eat? Focus on lean protein and complex carbs, which will fuel your workout, suggested White, who recommended a slice of whole-grain toast with almond butter, a banana with low-fat Greek yogurt, or a cheese and turkey roll-up.

Dehydration is another possible culprit of exercise-induced nausea, said White. "During exercise, the body loses water through sweating to cool down," White said. "So not drinking enough water ahead of time can increase the symptoms." The solution is straightforward: Drink water steadily throughout the day.

What if You Get Nauseous Mid-workout?

If you're in the middle of a workout and nausea hits, Dr. Richardson said it shouldn't be ignored. "Often, nausea is our body signaling that we are pushing ourselves too hard or that you're not resting enough between sets," Dr. Richardson said.

To calm nausea, dial back on your intensity and try walking around at a slow or moderate pace. "If you stop exercising too quickly, nausea may get worse because there will be a massive change in where the blood flow is going in a short period of time," said Dr. Babka.

That's one reason many races have participants walk down a shoot after they cross the finish line, Dr. Babka explained. If you're in a group fitness class, try walking to the water fountain or taking a step back and walking in place.

The bottom line? Exercise-induced nausea isn't fun. But if it only happens once in a while—and it's not accompanied by more severe symptoms like fever, bad muscle cramping, chest pain, a complete lack of sweating, or brown urine (which is a sign of a dangerous condition called rhabdomyolysis)—Dr. Babka said it's probably not something to be too concerned with.

If you constantly find yourself feeling nauseous, on the other hand, talk to your healthcare provider to rule out more serious medical conditions. Or, try scaling back your workouts: You may be over-training, and your body may be telling you to take it easy.

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