It’s workout time and you are READY! You blocked off your schedule. You set out clothes ahead of time. You’re optimistic about starting a new habit. So why are you suddenly feeling sick after just a few minutes on the elliptical?
First, know that this doesn’t translate to your fitness level. Experiencing nausea during workouts is common, and can be described as exercise-induced nausea.
What’s happening is this: As you begin to exercise, up to 80 percent of your blood flow is being diverted away from your stomach and GI tract and rushed to your hard-working muscles and lungs, says Tamara Hew-Butler, DPM, PhD, an associate professor of exercise science at Oakland University in Rochester, MI. For some people, this shift in blood flow can result in feeling nauseated.
Fortunately, you can minimize or eliminate exercise-induced nausea by adjusting a few elements of your routine.
What affects exercise-induced nausea
How soon you eat before exercising
A common culprit for feeling sick during exercise is consuming food too close to workout time. Hew-Butler says she can’t eat within two hours of a workout, but notes that others can eat immediately before and have no problems. “It’s really individual,” she says, adding that people need to experiment with different types of food and the timing of their pre-exercise meal to avoid getting nauseous.
As for snacks during your workout, unless you’re exercising for more than two hours, you don't need food. “If you're exercising for less than this, generally you don't need anything to eat to keep blood sugar levels stable,” Hew-Butler says.
How much water you drink during exercise
Or rather, how much you don't drink. Research shows that dehydration can lead to feeling sick during exercise.
Hydration needs vary from person to person, and while there's no "right" amount of water to drink, keep in mind that when you work out, the body loses water through sweat. The more you perspire, the more water you’ll need to make up for fluid losses. Keep a water bottle by your side while you exercise to stay on top of your sips. You'll know you're not getting enough if you notice signs of dehydration including thirst, headache, and dry mouth.
The intensity of your workout
If you’re a very driven person, you might be tempted to tackle exercise with the same all-or-nothing attitude, but here's a reason to pace yourself: Taking on too much too fast could be the cause of your discomfort.
“If you’re just starting exercise, you’re not used to the activity, so you may get nauseous in the beginning,” says Martin D. Hoffman, MD, a professor of physical medicine and rehabilitation at University of California, Davis. Going at maximum intensity on a stationary bicycle for just 30 seconds is enough to make many people nauseated. Hew-Butler says that people need to gradually increase both the duration and intensity of the exercise.
If, on the other hand, it’s a more-fit workout buddy who’s pushing you beyond your limits, ask to take the next session down a notch (or three). Or consider finding a new partner who’s at a similar fitness level.
In the end, finding out what’s causing your exercise-induced nausea is a process of self-experimentation, Hew-Butler says. “You have to find out what you can tolerate, and what makes it better and what makes it worse.”
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This article was reviewed for accuracy in January 2022 by Christi Smith, MS, CSCS, Associate Manager, Science Translation. The WeightWatchers® Science Team is a dedicated group of experts who ensure all our solutions are rooted in the best possible research.