Can You Take Pre-Workout On An Empty Stomach? – GGP Guide

One of the largest debates in the fitness community is whether or not you should work out on an empty stomach, and if so, should you take a pre-workout supplement?

While there are benefits to taking pre-workout supplements on an empty stomach, there are also concerns.

Will empty stomach supplements and workouts cause harm or provide benefits? We will dive in and find out to help clear up any confusion you may have.

Many fitness enthusiasts wake up and use the overnight fast period of sleep to continue through their morning workouts. Others enjoy eating a small meal before beginning their weight training routines.

Taking a pre-workout on an empty stomach can have some detrimental effects, though. A lot will depend on your tolerance to digestive system irritation and other adverse reactions. It is going to be different for each person.

The best option, should you choose to use pre-workout on an empty stomach, is to know what you can and cannot handle. Studying the ingredients, knowing your reactions, and the type of workout training you are about to perform will go a long way.

Another point of note is to understand that some pre-workout supplements are designed to be taken on an empty stomach. Other pre-workout supplement brands require enough food to avoid some side effects.

Before making the benefits a focus, the first thing to consider is to know what symptoms and issues you may encounter with taking pre-workouts in a fasted state.

Related Article - Does Taking Pre-Workout Break A Fast?

Can You Take Pre-Workout On An Empty Stomach? – GGP Guide

Low blood sugar

Pre-workout supplements are designed for more energy, and many are formulated to be taken on an empty stomach. However, when training fasted, you are susceptible to hypoglycemia. This is a condition when the glucose levels in your blood are too low.

The condition is easily resolved by having a snack or small meal. While this goes against training your body in a fasted state, it may be required for those with blood sugar issues.

Working out when your last meal was several hours prior, you can feel worse, and even develop stomach issues. The caffeine included in most pre-workout supplements may absorb into your intestines quicker but can also cause stomach burns.

Pre-workout consumption can give your fitness goals an energy boost. But, there are other concerns besides low blood sugar to consider.

Digestive problems

One of the most common side effects is experiencing digestive issues. When taking a pre-workout mix on an empty stomach, the stomach lining isn’t as protected.

Caffeine, as well as other stimulants, such as artificial sweeteners, can cause gastric distress. This distress comes from quick absorption that is delayed when you take a pre-workout formula on a full stomach.

The easiest way to prevent this side effect is to take your pre-workout after you eat some food. Your body will slow the absorption while it digests. The food will also act as a buffer to protect your stomach and intestines from the stimulants.

Read Also - Does Pre-Workout Make You Poop?


Increasing your energy levels is only one of the reasons to take your pre-workout. However, this can also cause you to become jittery while you exercise. While your muscles may enjoy the fuel to keep going, the rush you get can be disruptive.

Many people have what is known as niacin flush. The rash is a temporary skin condition when the blood rushes to the smaller blood vessels in your arms, legs, and face. It also comes with a jittery feeling or nervousness.

Most of the time, niacin can be avoided. It is added to give this rush, to let you know it is working. Some people looking for nervous system tingles enjoy the feeling, while others want to avoid it.

It is a personal call, and there is no evidence that this is a long-term condition and isn't harmful.

Also Check Out - Why Do Some Pre-Workouts Make You Itch?


A good pre-workout supplement will give you the energy to lose weight and promote your muscle pump that many gym goers are so desperate to achieve. However, when a "pre-workout on empty stomach" approach is used, it can also cause nausea.

Whether your sports supplement is designed for meals or not, even the organic compound formulas can make your stomach upset.

To prevent this, you should always start with a smaller dose to see how you react. Gradually you can build up your tolerance while on your fat burning or fitness journey.

Learn More - What Does Pre-Workout Feel Like?  


Another side effect that is often reported is dizziness or loss of balance. This can be the most dangerous side effect based on when it happens to you. For example, if you are in mid-set, you can stumble, fall or drop weights.

While it is difficult to pinpoint a specific cause of dizziness, it is usually due to lowered blood pressure. Because you are in a fasted state and working out on an empty stomach, your blood sugar levels are already low.

Taking the supplement can give you that energy boost to workout harder or push harder that can make you light-headed or feeling faint. If this happens, you should stop the workout and consume a few calories.

For athletes with this side effect, a lower dose or having something small before your workout is generally advised.

man dizzy after taking pre-workout

My Experience Taking These Pre-Workouts First Thing In The Morning

I have taken the following pre-workout supplements on an empty stomach every morning for a week. Here is what happened.

1. Woke AF Pre-Workout

With Woke AF, I found that the first few days, I was extremely dehydrated. Starting the fourth day, I added an extra 20 ounces of water about 15 minutes before my workout, which helped a lot.

The Vitamin B6 compound and coconut water gave me the niacin rush (which I enjoy) without the flush. However, I am used to the niacin effects, so your experience may vary.

With Woke AF, I was pumped and ready to enjoy my workout, which I did. I did not notice any added pumps or reps taking this without eating. As a pre-workout supplement, though, it does its job well.

Related Article - Woke AF Pre-Workout Review 

2. Performance Lab Pre-Workout

Performance Lab is one of my favorites to take before eating. The energy comes from red beetroot and coffee bean extracts. They also use BCAAs, Vitamin B compounds, and Vitamin D complexes to minimize that sugar crash.

With Performance Lab, I found I was boosted, gained the pump faster, and felt better throughout my entire workout.

3. C4 Pre-Workout

The C4 line from Cellucor is admittedly my go-to supplement before I work out. However, I typically take them with a meal and enjoy their boosts on the way to the gym.

When fasting, the results were the same. Cellucor's C4 does have a higher niacin flush than other supplements on the market, but that “it’s working” feeling really helps me to push an extra rep or two in during my routine.

Taking with or without food during an early morning fitness routine doesn't seem to be a factor, so you can go either way here. I see this as a benefit, and nausea or dizziness were not a factor for me with the C4 option.

Related Article - Cellucor C4 Pre-Workout Review 

c4 pre-workout on empty stomach

Artificial Additives & Sneaky Synthetics: Learn What To Avoid!

While most ingredients have a purpose that works towards giving you a boost in the gym, others are there purely for aesthetics. There are several label ingredients you want to avoid.

Artificial colors, such as Red No. 40 and Blue No. 1, are some of the most common dyes used to help the powder mix look more appealing. However, some studies link these artificial colors to carcinogens with nasty side effects and even cancer in animals (Red. No. 3). [1]

You also want to avoid listings of proprietary formulas. This is a technical loophole to protect the actual formula being used. While the FDA does require all ingredients to be listed in order of weight, they do not require individual amounts to be listed for a proprietary listing.

What this means for the average gym enthusiast is that you are getting what you expect, but you don't know how much or if there are any fillers.

You want to avoid fillers and any formula not backed by science. One of the most common options, though, is that instead of sugar or caffeine, some brands will use artificial ingredients. You want to stay away from these at all costs.

Artificial Additives & Sneaky Synthetics

Gentle Pre-Workout Ingredients For Training On An Empty Stomach

Some ingredients are better for empty stomach exercise performance. Below we discuss the ingredients you should be on the lookout for.

L-Citrulline + L-Glutathione

If you are looking for impressive muscle pumps, the combination of L-Citrulline (citrulline malate) and L-Glutathione is at the top of the list.

These two are known as urea cycle amino acids, meaning they break down in the kidneys [2]. Essentially they turn into L-arginine, which will help increase nitric oxide metabolism. Wider blood vessels and improved blood flow help to move oxygen to build muscle.

Creatine & BCAAs (Branched-Chain Amino Acids)

Instead of fat stores, creatine is a compound that helps muscle recovery and muscle building without adding fat.

Creatine is one of the most studied and proven supplements on the market and is found in the gym bag of virtually every serious fitness guru.

While creatine is a stand-alone supplement, its proven benefits are not hindered when added to a pre-workout drink.

BCAAs are proven to help protein breakdown and protect muscles during physical performance exercises. They are easily absorbed into the muscles and can prolong your workouts.

BCAAs help to block muscle fatigue, increase lean muscle mass, and even help reduce or eliminate muscle soreness. Aside from caffeine, BCAAs are the most popular pre-workout ingredient.

Related Article - Creatine Vs Pre-Workout 

MCT Oil (Medium-Chain Triglycerides)

A medium-chain triglyceride (MCT) is a more popular ingredient for empty stomach workouts. Commonly found in coconut oil, MCTs are easily absorbed and have a shorter length [3]. This makes them ideal for ingesting while fasting.

HMB (β-Hydroxy β-Methylbutyrate)

Hydroxymethylbutyrate (HMB) is shown to improve muscle growth and exercise performance. Can you exercise before eating while taking HMB? The research says yes. [4]

Easily absorbed and naturally occurring, but as a supplement is found in powder, pill, and tablet form. While it is one of the few ingredients that does not promote weight loss, your body naturally uses HMB to recover, which is ideal for older trainers.

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Taking Pre-Workout On An Empty Stomach FAQs

Does working out on an empty stomach burn more calories?

No, the caloric burn, whether you eat or not, is no different. What is different is which calories are burned. When working out without food, you will burn more fat calories instead of muscle stores calories.

What is the best pre-workout for fasted training?

The best pre-workout will improve focus, have minimal caffeine, and can even promote weight loss. Cellucor C4, Optimum Nutrition, and Performance Lab have some of the most popular and backed ingredient lists available, though.

Learn More - Can Pre-Workout Make You Lose Weight?

What should you eat after having pre-workout?

When taking pre-workout supplements, you will need to eat eventually. It is important to have good protein from nuts, yogurt, eggs, or even milk.

What are the best supplements to stack with pre-workouts?

The jury is still out on the best of the best, and new studies are showing up comparing different stacking options. Your body will also react differently than another person's body.

However, creatine, MCT oil (coconut oil), and beta-alanine are the most common and widely used empty stomach supplements stacked with pre-workouts.


With the right pre-workouts, your fasting workouts can help keep you motivated, pumped, and heading to the gym. With the right energy levels, motivation and supplements, your early morning workouts will improve and show you the results you need.

Is fasting right for you and your gym experience? It depends on you as a person and how you react. Trial and error, as well as talking with your doctor, will be the best course of action.






Last Updated on January 22, 2023