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Daniel Mesa

Does Pre Workout Break A Fast?

does pre workout break a fast

Over the past few years, pre-workout supplements have increased dramatically in popularity. However, along with the rise of pre-workouts came the rise of other fitness trends, such as fasting.

With many people fasting for benefits such as fat loss, many are left wondering: does pre workout break a fast?

The truth is that as long as your pre-workout has a marginal amount of calories (<40 calories), you will not break your fast with a pre-workout. Most pre-workouts fall well under this threshold, but you should check the label to make sure. 

In this guide, we will go over all of the science behind breaking a fast and also examine some of the key ingredients in a pre-workout that could play a role in the debate. 

Does Pre Workout Break A Fast? When It Does And When It Doesn’t

As we already touched on, the vast majority of pre-workout supplements will not break your fast so long as they contain an insignificant amount of calories. 

Based on the analysis we have done of the most common pre-workouts, none of them contain enough calories to really affect your fast. In fact, taking your pre-workout in a fasted state may have some benefits as it will increase the potency and decrease the amount of time it takes to kick in.

What Is Pre-Workout?: Uses And Ingredients

does preworkout break a fast

A common supplement that lifters use to improve their workouts is pre-workout. Usually taken before arriving at the gym, the supplement can provide higher energy, focus, and stamina if used properly. Generally, pre-workouts have ingredients that can be broken down into a few basic categories. 

The dosing of ingredients and selection will vary based on the pricing and manufacturer. 

Caffeine And Other Stimulants

In terms of what you actually “feel”, when taking a preworkout, the majority of the jitters and energy will come from the caffeine and any other stimulants in the product. Typically this will be between the 150mg-300mg range. If you are already exposed to caffeine through things such as coffee or energy drinks, you may find the feeling of preworkout to be familiar. 

On the other hand, if you have no experience taking caffeine, you will certainly be able to feel the increased energy levels and typical caffeine jitters. 

Pump Ingredients

Within a typical pre-workout, there will be ingredients such as citrulline meant to increase your blood flow so that you get a better pump in the gym. There are debates about whether this actually helps with muscle growth, but it will certainly feel good and make sure you can feel whatever muscle you are working out. 


Creatine is one of the few proven natural supplements that work in terms of building muscle.  To save you the hassle of mixing creatine with pre-workout many pre-workouts have begun to include creatine as a result. While it is nice to get all of your supplements in one, the timing aspect of pre-workout does not really matter for creatine. 

It takes some time for creatine to build up in your body, but as long as you are consistently taking the product on a daily basis, the rest does not matter. 

Focus Ingredients

Lastly, we have focus ingredients such as L-Tyrosine or Alpha-GPC that are meant to enhance your alertness and concentration. If you are someone that really likes to get locked in for your workout, these are the ingredients that you will get the most benefit from. 

Does Pre Workout Have Calories?

does pre workout have calories

Most pre-workouts contain some calories, but the amount is usually under 30 calories, which is insignificant in your total daily calorie consumption. 

How To Tell If Your Pre Workout Will Break Your Fast

You can always check the label of your pre-workout or contact the company to get an exact answer. 

Here are some of the most common pre workouts and their respective calorie counts

Pre-workoutCalories Per Scoop
Gorilla Mode20
Alani Nu10
Total War0

You should be aware that this is if your pre-workout is taken with simple water. If you like other people start mixing in things like protein, sport drinks, or honey into your pre-workout these are things that contain calories and need to be accounted for.

The Science Of Breaking A Fast

Technically speaking, consuming any amount of calories will break a fast. But the key thing to remember is that the majority of people fast for the benefits of weight loss, mental clarity, improved digestion, etc. 

You will still get all the same benefits as long as you stay under 50 calories or so. Again, this means that consuming even two scoops of most pre-workouts will keep you well under that limit. 

Furthermore, while the other benefits of fasting are nice, the key feature of fasting is that a limited eating window usually leads to less overall calorie consumption. Consuming 50 calories in the form of a supplement outside of this window will not really have any impact on your fasted eating window. 

Final Thoughts

If you are new to fasting, it is normal to want to be 100% sure that you are staying in a fasted state so that you can reap all the benefits. However, when it comes to pre-workouts, there is really nothing to worry about. 


What pre-workout will not break a fast?

The vast majority of pre-workouts will not break a fast as they do not contain a significant amount of calories. If you want to be extra safe, look for products that have under 40 calories per scoop. 

Does c4 pre-workout break intermittent fasting?

No, C-4 contains less than 5 calories which is not enough to kick you out of a fasted state. You will still get the same benefits even if you take C-4. 

Will 10 calories break a fast?

Technically, any amount of calories will break a fast but anything less than 50 calories will not really have a large impact on your overall metabolism and state. You will still get the same benefits so long as you stay under that threshold. 

Can you bring pre workout on a plane?

Yes, for the vast majority of countries, you can travel with pre workout on a plane