Pre-Workout on an Empty Stomach? When It’s Okay, When It’s Not

September 4, 2024

One of the most common pre-workout questions we get is whether it’s okay to take on an empty stomach.

The short answer is it depends.

On the surface, there’s nothing inherently wrong with taking pre-workout on an empty stomach, however, it may be a lot for your body to handle.

Depending on the caffeine level, taking it on an empty stomach can also lead to a sudden increase in energy, and a subsequent crash hours later.

If we can sum up our advice in a few key points…

If the pre-workout is a “fully loaded” pre-workout, like Pre-Workout Elite, we don’t recommend taking it on an empty stomach. If you’re a pre-workout veteran, this can be okay, but sip slowly.
If you’re new to pre-workout, we don’t recommend taking it on an empty stomach. If you do, sip it slowly, and start with half a scoop.

Here are tips for deciding whether to take your pre-workout on an empty stomach and if you do how to do so safely.

There are a few considerations to keep in mind, from the type of pre-workout to its caffeine levels to your experience and tolerance.

And, we have tips to make it easier to take your pre-workout on an empty stomach

If You Take Pre-Workout on an Empty Stomach, Sip Slowly

This is worth repeating. Regardless of the pre-workout you choose or your experience levels, here are a few reasons to sip it over 30-60 minutes.

First, it won’t hit you as hard. By sipping slowly, you allow your body to gradually adjust to the influx of caffeine and other stimulants, which helps prevent sudden jitters or an overwhelming rush of energy.

Second, it’ll be easier to absorb and digest. Taking it slowly gives your digestive system time to process the ingredients without causing stomach discomfort, nausea, or the dreaded energy crash that can follow a rapid spike.

Mix With More Water

If you take your pre-workout fasted, mixing it with extra water can help you sip it slower. This also helps to keep you hydrated, reducing the likelihood of dehydration-related side effects like headaches or cramps.

Factor to Consider #1: Caffeine Levels and Your Caffeine Tolerance

Caffeine is a powerful ingredient. And while it has been well-researched at doses approaching 400mg to support strength and performance, it can have downsides too.

If you’re not used to taking high amounts of stimulants, then taking a lot of caffeine on an empty stomach can hit you hard and lead to a crash later on.

In Pre-Workout Elite, we add AmaTea® Guayusa Extract to help limit the jitters. Guayusa Leaf Extract contains caffeine that gives you a smooth jolt of alertness and energy. The herb highlights the naturally occurring antioxidants and caffeine from guayusa for a cognitive uplift, without excessive jitters.* However, if you’re not used to high caffeine levels, you can get jittery and crash regardless.

If You Have a Low Tolerance for Caffeine, Don’t Take a High-Stim Pre-Workout on an Empty Stomach.

Instead, choose a moderate-intensity pre-workout.

For example, Kaged Pre-Workout Sport contains 188mg. Our health-first drink to support healthy weight loss, Clean Burn, contains 166mg and AmaTea® to help take the jitter edge off.*

If Your Pre-Workout Has More Caffeine, We Don't Recommend Taking On an Empty Stomach

We do not recommend taking Kaged Pre-Workout Elite, with 388mg of caffeine, on an empty stomach.

Factor to Consider #2: Total Amount of Ingredients and Your Stomach Tolerance

You know the saying of having a “weak stomach.” This can be particularly relevant when taking a pre-workout, especially if it’s loaded with a range of ingredients like amino acids, creatine, beta-alanine, and stimulants. Each of these ingredients needs to be absorbed, and when taken in high amounts, they can be tough on your stomach lining, leading to discomfort, nausea, or even cramping.

If you have a sensitive or “weak” stomach, the large scoop size of a fully loaded pre-workout can overwhelm your digestive system, especially without the buffer of food.

In such cases, it might be best to avoid taking it on an empty stomach altogether. Instead, consider having a small snack before, or opt for a pre-workout with fewer ingredients.

The ingredients themselves also matter. For example, all Kaged pre-workouts choose l-citrulline instead of l-arginine, because l-arginine commonly leads to GI and stomach distress.

Benefits of Taking Pre-Workout on an Empty Stomach

Faster Absorption

Without food in your stomach, the ingredients in the pre-workout, particularly caffeine, are absorbed more rapidly, leading to a faster onset of effects.

This can help you feel energized and ready to go within minutes, maximizing your focus, alertness, and overall performance during your training session.

It may also lead to quicker digestion of amino acids like L-Citrulline, which means the "pump" will hit you faster.

Helps Offset Downsides of Fasting

Taking pre-workout on an empty stomach can help offset some of the downsides of training in a fasted state, such as low energy levels or reduced mental focus.

The right pre can provide a boost in energy and alertness, helping you power through your workout without feeling sluggish or mentally fatigued. This can be especially beneficial for early morning workouts when your body’s energy reserves are low from overnight fasting.

This is why caffeine tops our list of the best supplements for fasting.

Downsides of Taking Pre-Workout on an Empty Stomach

While taking pre-workout on an empty stomach can offer quick energy, it also comes with some potential downsides.

Stomach Discomfort

One of the main issues is the increased likelihood of stomach discomfort, nausea, or even gastrointestinal distress. Without food to buffer the ingredients, the high concentrations of stimulants, amino acids, and other active compounds can irritate the stomach lining, leading to cramps or an unsettled feeling that can negatively impact your workout.

Energy Crash

Another significant downside is the risk of a rapid energy spike followed by a crash. When caffeine and other stimulants are absorbed quickly, they can cause a sharp increase in energy and alertness, but this effect can lead to an equally sharp crash later on.

Additionally, for those sensitive to stimulants, taking pre-workout on an empty stomach can amplify side effects like jitters, anxiety, or a racing heart, making it an uncomfortable experience.

Again, limit these downsides by drinking it slowly and choosing a pre-workout appropriate for your needs.

Kaged Pre-Workouts: All Stimulant Levels and For All Goals

Pre-Workout Sport: Perfect for beginners, this pre-workout has lower caffeine and fewer ingredients overall, making it gentler on the stomach and easy to tolerate, plus it comes at a great price point for those just starting.

Pre-Workout: A classic option that provides a balanced blend of ingredients to boost energy and performance, and it’s also available in a stim-free version for those who want to avoid caffeine while still getting the benefits.

Pre-Workout Elite: A fully-loaded, high-stimulant pre-workout designed for experienced users seeking maximum performance enhancement; it’s not recommended for beginners but is available in a stim-free version for those looking to avoid stimulants without sacrificing intensity.