I know it doesn’t make any sense, but pre-workout makes me tired, and I know I’m not the only one.

It’s confusing because pre-workout is supposed to give you a buzz, but it can actually leave you feeling drained.

It all comes down to the ingredients in pre-workout and how they impact your body.

In this guide, we'll make everything clear so you can understand what's happening and hopefully avoid crashing after pre-workout.

Let's just kick off by saying that it has nothing to do with you.

Healthy people worldwide feel tired after taking pre-workout supplements; in almost every case, it's down to the supplement, not your body. Pre-workout supplements contain a mix of certain ingredients designed to impact your body.

While pre-workout ingredients are chosen for a reason, there are some unanticipated effects on your energy levels.

To help explain why your pre-workout drink is making you feel tired, let's take a closer look at what it does and what the impacts are: 

tired from working out

1. Suppresses Your Appetite

One of the most important ingredients within your pre-workout supplement is a stimulant, most commonly caffeine. The caffeine is used to help wake you up and improve focus so you can get the most from your workout.

Average amount of caffeine in pre-workout supplements can be from 100-400mg in a single scoop.

When you consider that your average cup of coffee only has about 80-100 mg of caffeine, you can start to see how much caffeine your pre-workout drink actually contains.

Unfortunately, too much caffeine can have implications for your whole body, and this level of caffeine consumption actually impacts your appetite.

There is some evidence to suggest that caffeine impacts the production of hormones that make you feel hungry, so as a result, you'll end up eating less.[1]

This may seem like a good thing if you’re looking to lose weight, but when you up your physical activity and lower your calories, it puts a strain on your body.

This can make you feel drained and exhausted after your workout.

2. More Intense Training

Pre-workout contains everything you need to get an intense workout.

The creatine helps give your muscles energy, beta-alanine improves recovery time, and other amino acids help to increase blood flow. Caffeine or other stimulants can also give you a pre-workout rush.

Taking pre-workout supplements helps improve your exercise performance, which is a good thing, but you burn more calories and use more energy.

So it's not surprising that you feel tired after you finish your gym workouts because your body needs rest.

3. Adds To Dehydration In Intense Workouts

Dehydration can happen naturally during a workout as your body produces more sweat to cool down.

One of the potential side effects of pre-workout is that it can exacerbate these symptoms and make you more dehydrated.

This is largely down to a few ingredients within your pre-workout supplement, but it does vary depending on which brand you use.

Caffeine and creatine can add to dehydration, and when you combine this with an intense exercise program in the gym, it can leave your body craving water. Dehydration can cause headaches and fatigue, meaning you really feel pre-workout crash symptoms.

It’s important that you drink enough water and check the label on your pre-workout to see if there are any dehydration warnings.

4. Spikes Your Blood Sugar

Consuming pre-workout can have side effects when taking large doses, including elevated blood pressure, anxiety, and spikes in blood sugar.

Most pre-workout supplements contain artificial sweeteners and additives to make them easier to consume, but these can have a negative impact on your body.

This increase in blood sugar levels from the pre-workout will elevate your energy levels at first, but you’ll experience a crash after a few hours.

This can make you feel really tired after your workout and completely sap you of energy.

5. Caffeine High Followed By Lows (Crash)

You’ve probably experienced a small caffeine crash after a cup of coffee, but the caffeine crash after pre-workout is much more intense.

This is largely due to the really high caffeine intake from each scoop of pre-workout.

Many pre-workout supplements will have 300mg of caffeine in a dose which will give you a huge boost of energy. However, once the caffeine wears off a few hours later, you'll feel nausea, irritability, and tiredness.

If you’re consistently feeling a drop in energy after pre-workout, it's a sign that your caffeine tolerance is too high.

You should consider taking a few weeks where you avoid caffeine to reset your body and prevent a caffeine crash in the future.

tired shirtless man in the gym

How To Stop Feeling Tired After Pre-Workout Supplements

1. Use A Stimulant-Free Brand

One of the easiest ways to avoid a caffeine crash is to switch to a stim-free pre-workout.

These contain largely the same ingredients but don't have any caffeine or other stimulants to boost your energy levels.

While this may not give you the same rush before you exercise, it will help to avoid the negative side effects of an increased heart rate, intense fatigue, and sleep issues.

This can leave you generally feeling healthier and happier.

2. Consume High Calorie Diet

Nothing causes low energy like a lack of calories. Many people train in the morning, and it's easy to leave the house before you've had any food.

By consuming a mix of healthy foods before you train, you can actually increase your performance and stop the post-workout crash.

If you do start to feel drained after your training, then it's a good idea to consume food as quickly as possible.

A healthy meal with high amounts of carbohydrates and proteins will help to increase your energy levels quickly and make you feel better.

Learn More - Does Pre-Workout Fit the Keto Diet?

3. Avoid Consuming Extra Caffeine

For most people, the danger zone in terms of caffeine intake is around 700mg a day.

This may seem like a lot, but when you consider how much pre-workout has in a single drink, it's easy to see how you would go over that threshold.

Taking too much pre-workout is bad enough, and even a single coffee can lead to a caffeine crash.

Just make sure you stick to the recommended dosage and avoid any additional caffeine. 

4. Reduce Reliance On Pre-Workouts

Is pre-workout addictive? No, taking pre-workout itself isn't addictive, but caffeine can be addictive if it's consumed in high enough quantities, so it's a good idea to avoid any reliance on it.

Pre-workout is designed to help improve your performance and push your muscles to the next level, but it shouldn’t be required for every workout.[2]

If you do find that you’re having to take it more, or it’s impacting your sleep quality or your sleep schedule, then it’s time to cut down.

Only take one scoop a day maximum, and start taking breaks in between doses, so you're only having it 2-3 times a week.

water in cup in the gym

What Does A Pre-Workout Crash Feel Like?

A pre-workout crash is different for everyone, and it depends on how much you've taken and the specific ingredients within it.

Generally, as your pre-workout starts to wear off, you'll feel incredibly drained and lethargic.

You can also become irritable and even nauseous, and if the pre-workout has put you off your food, you may also start to feel really hungry, which can have a further impact on your mood.

A pre-workout crash can make you pretty horrible to be around, so it’s worth avoiding it if you can.

How To Avoid A Pre-Workout Crash

1. Test Your Tolerance

Your pre-workout crash is pretty much entirely caused by caffeine, so it’s a good idea to test your tolerance. Reduce your pre-workout doses over a few weeks and see how much you can handle without a crash.

It may be worth coming completely off caffeine for two weeks first to reset your body's tolerance.

2. Don’t Take On An Empty Stomach

Don't take pre-workout on an empty stomach. Eating well before a workout will help ensure you have the fuel in your body to support your activity.

Using slow-release foods like oatmeal, eggs, or nuts can help you maintain your energy levels for longer and prevent the crash later on.

3. Cycle Your Pre-Workouts

Cycling your pre-workout supplements is one of the best ways to limit the negative side effects on your body and maximize the benefits.

By taking your supplements for 4-6 weeks, and then giving your body 2-3 weeks off, you should stop your caffeine tolerance from increasing and limit any pre-workout crashes.

You should hopefully get more of a positive boost from the pre-workout too.

4. Try Non-Stim Pre-Workouts!

Does all pre-workout make you crash? No, but there’s definitely far less risk with a caffeine-free blend.

Switching to a stim-free pre-workout will still help your performance, but it should stop you from crashing a few hours later. We would recommend trying Transparent Labs Stim-Free Pre-Workout.

pre-workout making you tired

Pre-Workout & Tiredness FAQs

Do all pre-workouts make you crash?

Not all pre-workouts make you crash, but some high caffeine blends (like C4 pre-workout) are more likely to make you tired afterward.

How long does a pre-workout crash last?

The crash should generally only last 3-4 hours, but if your sleep is disrupted, it could continue into the next day.

Should you worry if you feel tired after taking a pre-workout?

It’s certainly not a normal reaction, but it is probably due to an increased caffeine tolerance. Try to lower your caffeine intake for a few weeks and see if it has an impact. If you have any concerns, then you should contact your doctor, who should be able to provide specific treatment to help you.

Can you take a pre-workout at night to help you sleep?

It’s really not advisable to take any supplements that contain caffeine in the 4-6 hours before you go to sleep because it can massively impact your sleep quality. This will leave you really tired the next day.[3]

Why does caffeine make me tired?

Your body produces adenosine receptors which are what make us feel tired. Caffeine blocks these receptors, but they are still produced.

When the caffeine is finally removed from your system, it means many of these receptors are released at once, making you instantly tired.


Pre-workout has a lot of benefits, but just as it raises you up before a workout, it can bring you crashing right back down afterward.

The high level of stimulants can work for you and against you, but if you want to avoid extreme fatigue after your workout, you really need to monitor your intake closely.

Hopefully, this guide has helped explain why your pre-workout might be making you crash and given you some valuable tips on how to avoid a big drop in energy levels after you train.



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Andrew White

Andrew White is the co-founder of Garage Gym Pro. As an expert fitness professional (gym building nerd) with over 10 years of industry experience, he enjoys writing about everything there is to do with modern fitness & the newest market innovations for garage gyms. When he isn’t testing out products for his readers, he’s usually out surfing or playing basketball.