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Why Do I Feel Sick When Exercising?

Ever Thrown Up During a Workout? Here's the Perfectly Good (and Normal) Reason Why

Many of us know the feeling: you're on the treadmill sprinting your heart out, when all of a sudden a gurgling, acidic sensation arises in your stomach. Your mouth is getting a little watery, and it hits you: you're going to be sick. Sometimes we can ease up on the exercise front and stop it from happening, and other times, well . . . it's a little too late.

While it's not necessarily a bad thing to throw up during a workout, we know that a lot of you don't want to vomit while exercising (It's disgusting! It's awkward! Where's the toothpaste!?), so let's look at some reasons it happens.


More often than not, it's because you're exercising really, really hard. Good job! You're giving it your all. "That pukey feeling is simply your body's pH dropping from the accumulation of lactate," said trainer and injury-prevention specialist Liz Letchford, MS, ATC. "You're reaching what we call your lactate threshold, or the point at which your body has reached its capacity for generating energy." (Hint: this is your "edge"!)

Want to increase your endurance, stamina, and ability to go hard in the gym without throwing up? "The more you train at this limit, the higher that threshold gets," she said. "And the more you'll have to push yourself in order to reach that threshold." Read: keep finding your edge, and that edge will be harder and harder to get to.


Think about what you ate before your sweat session . . . and when you ate it. You want to give yourself a solid 30 minutes of no eating before a workout. That window is imperative for your digestion and for everything to settle before you put your body through the ringer via exercise, so 30 minutes before your workout should be the cut-off for food.

In addition, you want to keep your pre-workout food incredibly simple so as not to cause digestive distress. Think simple carbohydrates: no heavy fats, high-protein foods, or high-fibre foods, as they can all upset your tummy.


Excess fluid in your stomach can create pressure and a sensation of nausea. While it's important to be hydrated, overdoing it might be behind your discomfort during exercise.

Image Source: POPSUGAR Photography / Kathryna Hancock
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