Taking a pre-workout supplement sometimes results in a speedy trip to the bathroom. Worse yet, you could end up with stomach discomfort or diarrhea during your workout!

So does pre-workout make you poop? Or is there something else going on with your routine leading up to the gym?

Find out what ingredients could be the culprit. And learn how to take back control of your bowels!

Can Pre-Workout Really Make You Poop?

The fact is, yes, taking a pre-workout supplement can cause a sudden bowel movement. However, not everyone will experience this effect because it depends on several factors.

To determine if you’ll experience any toilet trouble, it helps to look at the individual components of pre-workout.

Why Does Pre-Workout Make You Poop?

Pre-workout supplements are a mix of compounds aimed at increasing energy and performance in the gym. While supplement formulations vary significantly between brands, some common ingredients could make you go number two.

7 Ways Pre-Workout Can Make You Poop

1. Caffeine

One ingredient shared by nearly all pre-workout supplements is caffeine. This stimulant boosts energy levels before hitting the weights.

Unfortunately, studies show that caffeine results in an “increased desire to defecate” ¹. And this effect can occur within just 10-15 minutes of consumption.

For comparison’s sake, a regular cup of coffee contains 80 to 150 mg of caffeine. In contrast, pre-workouts contain 150 to 400+ mg of caffeine!

Therefore, the high doses of caffeine in pre-workout supplements could intensify the urge to poop.

This graphic shows the relative caffeine content of coffee vs pre-workout.

2. Vitamin C

Some pre-workout supplements also contain large amounts of vitamin C, which scientific reviews suggest can have a laxative effect².

But the studies refer to mega doses of 2,000 mg or more per day. In comparison, a pre-workout supplement such as C4 contains only 250 mg of vitamin C.

So unless you’re very sensitive to this vitamin, you should be fine.

C4 pre-workout contains 417% of the recommended daily value of vitamin C. But that still shouldn’t cause issues for most people.

3. Vitamin B12

Another vitamin found in some pre-workout concoctions is B12. And B-complex vitamins are known to stimulate muscle contraction in the digestive system, which can make you feel the need to “go”.

So if you’re experiencing this issue, check your supplement label for high levels of B12 or other B vitamins.

4. Magnesium

When it comes to supplements that can make you poop, magnesium is at the top of the list. That’s because magnesium draws water into the intestines and stimulates bowel activity.

However, only a handful of pre-workout supplements I reviewed contain magnesium, and the dosage is less than the recommended daily intake. For example, BSN N.O.-XPLODE contains only 30% of a day’s supply of magnesium.

Therefore, magnesium probably isn’t the main contributor to your pre-workout poops.

N.O.-XPLODE has 125 mg of magnesium. By comparison, magnesium supplements often contain 400 mg or more.

5. Yohimbine

Yohimbine is a compound found in some pre-workout and fat-burning supplements. While it may be an effective stimulant for weight loss, it can also cause an upset stomach and other adverse effects³.

In my experience, taking yohimbe bark extract on an empty stomach can result in “emergency evacuation.” However, supplements with yohimbine HCl seem to cause fewer adverse effects.

6. Added Sugars

In addition, some pre-workouts contain artificial sweeteners known as sugar alcohols for flavoring. However, these zero-calorie additives don’t absorb well in the gut and can cause diarrhea in some people.

7. Water

Lastly, unless you’re “dry scooping,” you probably mix your pre-workout powder with water. And drinking a glass of water is a surefire way to get your digestive system moving, especially in the morning.

One way around this is to take your pre-workout with less water. As little as 3 ounces is usually enough to dissolve the powder. Just make sure you drink plenty of water throughout the day!

Other Factors Relating to Pre-Workout Poops

So far, we’ve talked about the ingredients in pre-workout. But how and when you take these supplements can also affect whether you visit the throne after.

Dosage

As you probably know, the little plastic scoop provided inside the container dictates the serving size. But a full scoop isn’t the correct dosage for everyone.

If you’re experiencing side effects like jitters or running to the bathroom, then consider scaling back to half of a scoop. Once the symptoms subside, you can gradually increase your dose if necessary.

Timing

Of course, you take pre-workout shortly before starting your training. But whether you work out in the morning or the evening could result in different effects after you take it.

In other words, you’re less likely to experience undesirable consequences if you take pre-workout later in the day.

How Long Does Pre-Workout Take to Kick In?

Empty Stomach

Another factor is how much food you have in your stomach. Taking pre-workout on an empty stomach is more likely to cause immediate poops or digestive discomfort.

That means you could be better off taking your supplement with a healthy pre-workout meal.

Minimal Mixtures

A second option is taking a pre-workout supplement with fewer ingredients. With less stuff in the mix, you decrease the chance for side effects and narrow down the possible culprits should you have an issue.

Homemade Pre-Workout

Brand name pre-workouts are a gamble. Some companies hide ingredients and doses behind proprietary blends, so it’s hard to know what you’re getting.

That’s why I started making pre-workout at home using the active ingredients found in store-bought supplements. This DIY approach saves money while giving you complete control over what you put in your body.

Click here to get 5 Homemade Pre-Workout Recipes.

Conclusion

Your pre-workout can intensify your workouts as well as your trips to the toilet. But now you know what ingredients to watch out for to mitigate the risk. And how to take your pre-workout to ease your stomach.

If you found this article enlightening, make sure you check out some of my other pre-workout and supplement information below!

References
1) Lohsiriwat, Supatra, Pahurat Kongmuang, and Somchai Leelakusolvong. “Effects of caffeine on anorectal manometric findings.” Diseases of the colon & rectum 51.6 (2008): 928-931.
2) Iqbal, Khalid, Alam Khan, and M. M. A. K. Khattak. “Biological significance of ascorbic acid (vitamin C) in human health-a review.” Pakistan Journal of Nutrition 3.1 (2004): 5-13.
3) Kearney, Thomas, Nora Tu, and Christine Haller. “Adverse drug events associated with yohimbine-containing products: a retrospective review of the California Poison Control System reported cases.” Annals of Pharmacotherapy 44.6 (2010): 1022-1029.