We asked a PT and a nutritionist if you should be worried about vomiting during a workout.

Picture this: You’re in the middle of a spin class or running on the treadmill. Doing ~F45~ even. Everything’s going great and in that moment, you’ve never been stronger or healthier, and you’re living your best life.

Then your stomach starts to turn and before you know it you feel like vomiting all over your fitness instructor.

Even if this has never happened to you (or you’ve never worked out hard enough for this to be you), chances are you’ll have seen it happen to someone else.

But if it does happen to you, should you be worried? Is it a good thing, a sign that you’re dominating your workout, or a warning sign you’re dominating just a tad too much?

In case you ever do find yourself looking for the nearest bin during or after exercising, we asked a PT and a nutritionist for the low down on things coming back up.

So, is a cheeky workout chunder something to lose sleep over? Short answer? No. But also yes.

According to Nutritionist and Dietitian, and founder of Shape Me, Susie Burrell, there are a couple of reasons you might be vomiting after physical activity.

“The first is that some people suffer from a low threshold of lactate, or lactic acid, the by product of high intensity training in the muscle,” she told Mamamia.

“When you see athletes spewing up, that’s when they’ve reached their threshold. Different people have different thresholds, if you’re someone who is regularly participating in high intensity activity that’s depleting the muscle of glycogen and that’s when you can get a lactate overload and vomit.

“The second time is if someone has not eaten carbohydrates for a long period of time or has issues with blood glucose control, or they might be diabetic, they can sometimes go into a state called metabolic acidosis, which is basically where you’ve got no available fuel and it can make you feel ill. Often this means they haven’t got their carbohydrate timing right, but this is quite rare.”

PT and 28 By Sam Wood lifestyle program founder, Sam Wood most commonly sees vomiting during or after workouts at those early morning sessions you keep booking but also snoozing through.

"Some people feel they can't train on an empty stomach, but if you're eating just before a cardio based intense session with jumping and landing, lots of sit ups where you're squashing your stomach repeatedly, and high intensity movements, that can trigger a bit of a vomit. Some people eat in the car at 5:45am and wonder why during a hard warm up they're not feeling too good," he told Mamamia.

"I've witnessed it all, but it's one of those things that's a person-by-person situations. It's also hard because you don't want to be that one person in the class who has to stop or take a break, then before you know it, you've gone a bit too far.

So now you know the reason you might vomit during or after exercising, should you be fazed if you do?

"I would be concerned if it was happening regularly. If you're not an elite level athlete training at a very high intensity, if you were just doing a spin class and every so often you vomited, I would seek medical advice because there could be something going on. It's not a normal thing," Burrell warned.

"Rather than being a normal side effect of intense exercise or a sign of a good workout, vomiting is a physiological response to something that's not quite right."

Wood agreed, adding "19 times out of 20, it'll happen to someone who's just coming back to exercise or just starting. They still don't know their body yet. They're pumped and getting caught up in the energy and excitement, they're on a mission to really get into shape and they go a bit too hard too early."

Essentially, if you're not an elite athlete who is participating in strenuous, high level intensity, you shouldn't be throwing up at any point in your workout. If you're someone who thinks they're 'just a vomitor', seeing your GP and talking through your symptoms is the first step to take.

But if it happened to you that one time during a particularly brutal session or on a hot day, there are some steps you can take both before and after working out to ensure it doesn't become the norm.

LISTEN: The Well's Robin Bailey and Bec Sparrow discuss how why you're working out matters (post continues after audio...)

From a nutritional perspective, Burrell insisted hydration and, wait for it, carbohydrates are your insurance plan before hitting the gym, or whatever bit is you do to keep active.

"You need to consume 300 - 500 mL of fluid in the 30 to 60 minutes prior to exercise, be sipping throughout the session, and drinking at least 500 mL to a litre in the hour following," she advised.

"If you're a salty sweater or are prone to cramping (if you can taste or feel the salt on your face post-workout, this is you), think about adding like a Hydralyte to your water bottle or sipping a no sugar sports drink to replace those salts.

"Exercising also requires a certain level of carbohydrates to allow the body's physiology to fuel itself accordingly. In the hour or two before is probably the most important time to consume carbs, if you grab a piece of fruit, an energy bar or a slice of toast with peanut butter or avocado, that'll ensure you won't have those nausea side effects.

Burrell also recommended a protein and carbohydrate combo for straight after your workout to help your muscles repair for your next workout. Greek yoghurt and fruit, a latte, nut bar, bliss ball are all great options.

Now we've covered all the sciency, practical stuff, we know what you're thinking. What the hell do I do if I'm in a class and feel like I'm gonna spew?!

"It's important that you're not embarrassed to tell your trainer how you feel. You can always move onto something else or give a certain exercise a breather, so you can still feel like you got a great workout in but didn't overdo it," Wood said.

"If you feel like you're going a bit hard, back off. Listen to your body early on rather than waiting 'til it's, um, too late."

Wise words Sam Wood. Wise words.