7 Reasons for Nausea After a Workout

From time to time, while working out and chasing that runner's high or back squat PR, you may suddenly find yourself keeled over, wanting or needing to puke. Research has indicated that it is known as exercise-induced nausea.

Nausea after a workout might be caused by what or how much you've eaten before exercising, your exercise environment, or supplements. However, by doing things like staying hydrated or taking it easy during a workout, you can get your nausea under control. Read on to learn more.

1. Body's Response to Exercise

Research authors explained your digestive system is to blame for a nauseating experience. More specifically, exercise interferes with the gastrointestinal (GI) tract, resulting in symptoms like nausea, vomiting, or queasiness.

Additionally, there's a misconception that getting queasy during or after exercise indicates your overall athleticism. "From beginner exercisers to Olympians or endurance athletes, exercise-induced nausea can affect anyone," Brian Babka, MD, sports medicine specialist and Northern Illinois University Athletics team doctor, told Health.

2. Dehydration

Dehydration is another possible culprit of exercise-induced nausea. "During exercise, the body loses water through sweating to cool down," Jim White, RDN, an exercise physiologist and owner of Jim White Fitness and Nutrition Studios in Virginia, told Health.

While a person is losing water through sweat, the blood flow to the gastrointestinal (GI) tract may weaken. The result is worsened GI symptoms like nausea.

3. Exercising in Heat or High Altitudes

Nausea may occur when you're working out in hot temperatures. You lose a lot of water through sweat when you combine exercise and heat.

Nausea might occur if you exercise at high altitudes, such as completing a race in a mountainous area. Altitude sickness, or acute mountain sickness, results from reduced oxygen levels and air pressure.

4. Physical and Mental Health Conditions

Various health conditions and issues may be the root cause of your nausea as you exercise. These can be physical or mental health conditions like:

• Anxiety or stress
• Appendicitis
• Depression
• Functional dyspepsia
• Gall bladder diseases
• Migraines
• Motion sickness
• Myocardial infarction, or a heart attack
• Norovirus or traveler's diarrhea
• Panic disorder
• Peptic ulcers
• Severe pain

If you believe your nausea may be because of a physical or mental health condition, consult a healthcare provider or mental health professional as appropriate.

5. Pre-Exercise Eating and Drinking

What you eat and drink before working out matters. "The largest factor in whether or not you'll experience this nausea is what and when you ate ahead of time," said Dr. Babka. You also have to consider how much you've eaten.

Eating Too Little

For some people, not eating enough—or fasting for long periods—before a workout induces nausea. Research found that the longer you go without eating prior to exercise, the more severe the experience of nausea may be.

Eating Too Much

Exercising on a full stomach increases feelings of GI distress, including nausea. Specifically, one review said that high protein and fat intake before exercise leads to intense nausea. Drinking too much fluid has the same GI effects.

Slow-Digesting Foods

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.

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
• A cheese and turkey roll-up

Timing

Nausea may also be an issue, depending on when you decide to eat. "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," said White.

To avoid nausea, figure out a window that works for you. "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," added White.

6. Strenuous Exercise

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. There's less blood distributed to the digestive organs, which puts a pause on the processes that break down food in your stomach.

"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 exercise, like high-intensity interval training (HIIT) that involves bursts of vigorous exercise, can also exaggerate this response.

7. Supplements and Medications

Several supplements have the potential to cause nausea when you're physically active, including:

• Caffeine
• Electrolyte supplements
• Exogenous ketones
• Glycerol
• Iron
• Medium-chain triglycerides
• Sodium or sodium bicarbonate supplements

Also, some medications may have a side effect of nausea, such as:

• Analgesic medications (e.g., opioids)
• Antibiotics
• Antidepressants
• Antihypertensive medicines
• Non-steroidal anti-inflammatory drugs (NSAIDs)
• Oral contraceptives
  

Prevention

There are several ways to help prevent nausea during a workout. Preventative actions include:

• Avoiding high doses of caffeine
• Getting progressively acclimated to high-temperature environments
• Keeping cool throughout your workout
• Limiting large meals or certain foods close to workout time
• Reducing exercise intensity when necessary and possible
• Reducing supplement use or taking supplements hours ahead of a workout or intense activity session
• Staying hydrated by drinking water steadily throughout the day and while working out
• Using relaxation techniques for stress or anxiety

Treatment for Nausea After Workout

If you end up having nausea after you finish physical activity, one thing you can do is sit still in a quiet place. Movement can worsen nausea.

You could keep a pack of crackers or a gelatin cup in your workout bag. Bland and water-based foods can be beneficial for getting rid of a nauseous feeling.

Another treatment option may be anti-nausea medications. Remember that it can take between 30 and 60 minutes to work after use.

How To Address Mid-Workout Nausea

If you're in the middle of a workout and nausea hits, it shouldn't be ignored, Michael Richardson MD, a family physician at One Medical Group in Boston, told Health. "Often, nausea is our body signaling that we are pushing ourselves too hard or that you're not resting enough between sets," said Dr. Richardson.

Dial back on your intensity to calm nausea, and try walking around slowly or moderately. "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, explained Dr. Babka. If you're in a group fitness class, try walking to the water fountain or stepping back and walking in place.

A Quick Review

Dehydration, high-fat intake before a workout, and certain supplements or medications are some reasons you may be nauseous after exercise. The nausea is treatable but can also be prevented. Still, if you constantly feel nauseous, talk to a healthcare provider to rule out more serious medical conditions.