You’re totally crushing your spin class and your post-ride smoothie is in sight when suddenly you think in a panic: How the heck do I unclip my shoes from this bike? I’m about to puke. Don’t worry, it happens. (Seriously, a 2014 Sports Medicine study found that 30–50 percent of athletes experience gastrointestinal discomfort during exercise, and yes, that includes vomiting.)

So what’s the deal? The answer may be in your pre-workout snack, according to Stacy Goldberg, BSN, nutrition consultant, CEO and founder of Savorfull. Which is why “being connected to what you eat and how you feel when you work out is so critical,” she says. “Many athletes have not made that connection. You have to practice a lot of mindfulness when it comes to eating before you exercise.”

Ready for a vom-free workout routine? Here are 4 tips for avoiding the uncomfortable scenario of exiting a workout in search of a trash can.

1. Never eat new foods before a workout

“Usually, when someone is starting a new fitness program or isn’t a regular athlete or exerciser, new foods are being consumed while they’re also doing new workouts,” Goldberg says. “So therefore, they might be consuming things that could cause gastric upset, nausea, and vomiting if their body isn’t used to those foods.”

She recommends eating things you know will sit well with you (and starting a food journal to track how different pre-workout meals affect you during your sweat sesh).

2. Don’t eat too much

So you’re down to stick with your go-to protein bar as a pre-workout snack, but Goldberg cautions that limiting yourself to foods your body is familiar with won’t matter if you eat too much of them at once.

“It’s never a good idea to eat a large meal and then go work out,” she says. “Stomach upset and complaints are more common when eating a meal within a couple hours of exercising, so really you need to give your body a good three hours to digest your meal.”

Her advice? Eat something small about 30 minutes to an hour before working out, and avoid foods that are fried, fatty, or too high in fiber (all of which make them tough to digest quickly). Instead, opt for a carb-and-protein-rich snack, like oatmeal sprinkled with nuts or a banana and almond butter.

3. Don’t chew gum

“I see a lot of nausea with people who chew gum during their workouts because gum has a lot of artificial sweeteners and sugar alcohol,” Goldberg says.

She recommends staying away from pre-workout foods that contain sugar alcohols such as erythritol, xylitol, and sorbitol (which are often found in protein bars and even avocados) because they can cause gastrointestinal upset.

4. Stay hydrated (but don’t over-drink!)

Goldberg says finding a balance between being properly hydrated and having so much fluid in your stomach that you’re nauseous is critical when exercising.

The trick? Sip on water during class if you start to feel thirsty, but it’s probably not a good idea to chug a ton of H2O. (Is there anything worse than trying to power through box jumps when you can feel the liquid sloshing around in your belly?) Your stomach (and your fellow classmates) will thank you.

In your hunt for healthy snacks, check out the protein bar Carrie Underwood always keeps in her gym bag or the ones these 9 fitness trainers swear by.