Why You Might Feel Nauseous at the End of a Run

Tired and nauseous runner
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Feeling like throwing up after running—or actually doing it—is not fun, nor is it uncommon. Nausea or vomiting during or after a run can happen for a few different reasons.

Most of the time, while unpleasant, it's not serious, and it's usually something you can manage. If you get nauseous after running while training for a race, consider it an opportunity to determine the cause and fix it before the event.

Reasons Why You Feel Sick to Your Stomach

Even if you usually have an iron stomach, intense exercise can reduce the flow of blood to your digestive system. The result is that queasy feeling, especially when paired with these common causes of post-run nausea.

Pre-Run Meal Timing

If you ate less than an hour before your run, that's too close to your workout and it's possible that you'll feel nauseous and even throw up whatever you ate. It's OK to have a light, healthy snack about 90 minutes before your run.

Try to eat something that is easily digestible, such as toast with peanut butter or a banana. If you eat something that takes longer to digest, like fatty or fried foods, you should wait at least 2 hours before running.

Dehydration

Nausea is also an early symptom of dehydration. Be sure to drink water before your run. You should be fully hydrated before you start running. While running, obey your thirst and drink when you are feeling thirsty.

In general, that means about 6 to 8 ounces of fluid for runners running faster than an 8-minute per mile pace, and 4 to 6 ounces of fluid every 20 minutes for those running slower than that. But also be aware that drinking too much water can also cause nausea.

During longer workouts of 90 minutes or more, some of your fluid intake should include an electrolyte sports drink to replace lost sodium and other minerals. And don't forget to rehydrate with water or a sports drink after your run, too. If your urine is dark yellow after your run, you're dehydrated and need to keep rehydrating. Aim for urine the color of light lemonade.

Some runners don't drink during their runs because they don't have access to water if they're running outdoors. An easy solution to that problem is to run with a hand-held water bottle or belt carrier made specifically for runners. If you really don't like to carry water with you, plan your route so that you have access to water fountains or a strategically placed water bottle.

Hot Weather

Use caution when the conditions are extremely hot and humid. Even if you attempt to stay hydrated when running in those conditions, you could still be at risk for nausea, dehydration, and other heat-related illnesses. Run indoors or reduce the distance or intensity of your workout to help you stay safe when running in the heat.

Your Sports Drink or Energy Gel

If you've consumed a sports drink or energy gel product while running, your nausea could be a reaction to the food or beverage. Some runners find that their stomachs are sensitive to sugary sports drinks or energy gels. This is often the case if you combine a drink and a gel. Together, they provide too much sugar for your stomach to handle.

To mitigate this issue, try making your own rehydration drink by adding 4 tablespoons of lemon juice, a couple of pinches of salt, and 2 tablespoons of honey to 16 ounces of water. Instead of energy gels, try dried fruit, nuts, or honey (which is available in portable Honey Stinger packets).

Overdoing It

Another possible cause of nausea during or after running is that you simply ran too hard and overexerted yourself. You may also feel more tired than usual, or moody and irritable, or slow to catch your breath. This feeling can be a sign that you are lacking some fitness for the pace you were running.

Avoid this problem by making sure you're warmed up before starting an intense run, and running at a pace that you're ready for. (Tip: During a distance run, you should be able to hold a conversation while running.) Always increase your pace, distance, or time slowly and gradually—and never all three at once.

What to Do When Nausea Strikes

If you feel like you might throw up after a run, sip some water very slowly, in case you are dehydrated. If heat is a likely culprit, make sure you get into an air-conditioned space as soon as possible to cool off.

Whatever the suspected cause may be, don't force yourself to continue running (although you should not skip your cool-down, as it may help you feel better). Just rest. If you're still feeling sick or throwing up after several hours, you may want to consult a healthcare professional.

If your post-run nausea was short-lived, and you feel pretty confident that you know what caused it, you should be able to run again within a day or two. If your nausea was due to overexertion, scale back your intensity and be sure to warm up and cool down adequately.

If you think your pre-run meal or on-the-go nutrition was the culprit, experiment to see what foods and what timing work better for you. It's always better to experiment when you are training so that you will be comfortable during a race, if you have one planned. Consider adding notes on nutrition to your training log so you can look for patterns and keep track of successes and failures.

Nausea Before a Run

If you're struggling with nausea, vomiting, or some other gastrointestinal discomfort even before you lace up your shoes, it's best to skip your run.

The "above the neck/below the neck" rule is a good guideline: If you are feeling unwell, but your symptoms are all above the neck (runny nose, sore throat), you can run if you feel up to it. Below the neck symptoms, including nausea, are a sign that you should stay home and rest.

Nausea on Race Day

If you're about to line up for your race and aren't feeling well, it's highly possible that your nerves are kicking in. It's not unusual to feel anxious about a race, especially after all the hard work you've put in to train and prepare for this day, but all of that training is what will ultimately get you through it.

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  1. Prado de Oliveira E, Burini RC, Jeukendrup A. Gastrointestinal complaints during exercise: Prevalence, etiology, and nutritional recommendations. Sports Med. 2014;44 Suppl 1:S79-85. doi:10.1007/s40279-014-0153-2

  2. McDermott BP, Anderson SA, Armstrong LE, et al. National Athletic Trainers' Association position statement: Fluid replacement for the physically active. J Athl Train. 2017;52(9):877-895. doi:10.4085/1062-6050-52.9.02

  3. Prado de Oliveira E, Burini RC. Food-dependent, exercise-induced gastrointestinal distress. J Int Soc Sports Nutr. 2011;8:12. doi:10.1186/1550-2783-8-12