Does Pre-Workout Make You Poop?

Medically reviewed by Dr Dimitar Marinov

Imagine you’ve taken your pre-workout and are ready to kickass at the gym when suddenly, your stomach churns, and you know you’ve got to make a pitstop to the toilet. No one wants to experience this when you’re in the zone, so you’ve got to ask the question, “Does pre-workout make you poop?”.

Pre-workouts are often comprised of ingredients that can speed up your digestive system and can lead to an increase in bowel movements. So there’s a chance they may make you feel like you need to go, but that’s not always the case.

Read on to find out how pre-workout affects your bowel movements to find out whether or not taking pre-workout makes you poop and how they do it.

What’s a Pre-workout

What’s a pre-workout? It’s a supplement people use before exercise to boost athletic performance. Whether it’s hitting the gym or any physical activity, pre-workout formulas include a combo of ingredients designed to amp up your focus, endurance, and energy, allowing you to push harder and longer. You take it right before your workout, and it comes in powder or pill form. 

Why do Pre-workouts make you poop?

There are several reasons why pre-workout makes you poop, and most of them have something to do with the common pre-workout ingredients. Here are our culprits for the digestive upset you may feel from taking a pre-workout:


Many pre-workout supplements use caffeine which is the number one culprit for giving people the pre-workout poops. In some cases, you can have up to 600mg of caffeine in a pre-workout serving. That’s more than 6 cups of coffee per day.

Caffeine stimulates the contractions in your colon and can exert pressure on the sphincter, causing it to contract as well. Both of these effects can result in you needing to poop faster. Likewise, caffeine also boosts your metabolism, leading it to function at a faster rate than it usually does. 


Magnesium is another culprit found in a pre-workout powder that can make you poop. It’s a key ingredient in providing energy to your muscles. Unfortunately, when you ingest too much magnesium, it can draw higher amounts of water into your intestine, which could potentially speed up digestion and lead to you feeling like you need to poop.

Sodium Bicarbonate:

Sodium Bicarbonate (baking soda) is used in some pre-workouts and is often an ingredient for homemade pre-workout remedies. Unfortunately, baking soda builds up the CO2 in your stomach, which can lead to pre-workout diarrhoea. 

Vitamin C:

Vitamin C is also often included in a pre-workout supplement. They add a nice touch of flavour and can help with recovery to a degree. Unfortunately, when taken in large doses, Vitamin C can upset your stomach, making your digestive system work faster.

Artificial Sweeteners:

Pre-workout supplements also contain artificial sweeteners to make their drinks taste better. Research shows that consuming large amounts of sweeteners can upset your stomach and almost have a laxative effect. 


There aren’t many pre-workouts with lactose in them, but it is a common pre-workout ingredient that has been known to cause digestive issues, especially in people with lactose intolerance. In cases where the body can’t make enough lactase to break down the lactose, the lactose will sit in the stomach while being broken down by bacteria, which could cause digestive discomfort and diarrhoea.  

Other factors that could make you poop

Aside from the ingredients, there are a few other factors that contribute to giving you the pre-workout poops. Here are a few:

When you take the pre-workout:

Timing is everything. When you take your pre-workout, it will have significant effects on when you need to go to the bathroom. For example, if you take the pre-workout on an empty stomach, your body will absorb its ingredients pretty fast, which could make you need the toilet faster. 

Likewise, if you feel that you need the toilet, taking a pre-workout is just going to increase your bowel movements. You’ll experience fewer digestive issues if you take a pre-workout when you have food in your stomach. Having food in your stomach acts somewhat as a buffer so that your body doesn’t absorb the pre-workout ingredients too fast.

The dosage you take:

A common thread that we saw in all of the ingredients above was that you’d often experience digestive issues when you consumed too much of one of them. Watch your dosages so that you can avoid the possible side effects of taking too much.

Alternative pre-workouts that won’t make you poop

Okay, so now we’ve spoken about all the pre-workout ingredients that can make you poop. But is there any way to avoid this rather uncomfortable experience? Yes, there is. Here are some alternatives to your usual pre-workout supps:

  • Use stimulant-free pre-workouts 
  • Use natural sweeteners instead of artificial ones
  • Use the recommended dosage instructions
  • Lower dosages if need

Final Thoughts

There’s nothing worse than getting into a workout session and then suddenly needing the toilet. Unfortunately, for some of us, pre-workouts just seem to leave you with an upset stomach, thanks to their laxative effect. Thankfully, knowing what ingredients make you poop more than others can help you select your pre-workouts more strategically.

Leave a Reply