How Pre-Workout Affects Sleep Quality (And How to Avoid Sleep Disruption)

If you’re like millions of gymgoers, using a pre-workout supplement to make your morning workout seem a little less daunting is a daily occurrence. Furthermore, if your pre-workout contains all of the most common ingredients in its formula, then your training is further amplified by the presence of caffeine.

Caffeine is the most trusted and widely consumed stimulant in the world, consumed habitually by hundreds of millions of people in North America alone — usually in a coffee-based form — to raise their level of alertness and mental clarity early in the morning. It just so happens that caffeine has also been proven to benefit workout quality. 

Therefore, combining caffeine with several other ingredients that improve blood flow and delay time-to-exhaustion early in the morning can help you to bang out a glorious workout session, and then allow you to carry on with the remainder of the as your mind and body continue to operate at an enhanced level.

On the other hand, if you prefer to exercise in the evening and require pre-workout as post-work pick-me-up, the question becomes far more complicated to answer. Sleep quality is an important part of the training equation, and compromising on sleep quality can seriously blunt the effectiveness of your exercise in the long run.

So the question needs to be asked, can pre-workout hurt your sleep quality? In other words, does pre-workout keep you awake, and if it does, how late is too late for pre-workout? It’s important that you get well-sourced answers to these questions before you make adjustments to either your pre-training supplementation strategy, or your exercise timing in general.

Why Sleep Matters for Training and Recovery

Several direct links have been established between the duration of sleep, the quality of sleep, and multiple markers of performance, especially in the realm of fitness. For example, studies have shown how a reduction of sleep quality compromises the effects of hormones that are responsible for muscle repair and recovery (1), and also hinders carbohydrate metabolism and endocrine function. (2)

In separate studies, inadequate sleep was shown to clearly reduce leg strength and endurance of military personnel (3), and lowered the time to exhaustion of ultramarathon runners and triathletes. (4) It also decreased the performance quality of volleyball players and runners due to a decline in minute ventilation (5), and reduced the sprinting performance of runners due to reduced muscle glycogen levels. (6)

On the other hand, lengthening the average sleeping time of collegiate basketball players resulted in improvements to both their sprint times and shooting accuracies. (7)

Muscle repair, hormone balance, and next-day performance

We’ve established that sleep matters when it comes to measurements of physical performance, but the question is, why does it matter so much? The source of the answer is rooted in what transpires within your body while you’re resting and recovering in the aftermath of your training. 

First and foremost, gains to muscle size and strength occur during the periods between training sessions. One of the purposes of resistance training is to maximize the exertion of your muscles in ways that cause strategic damage to the fibers so that they can be rebuilt in a stronger and more durable form between workouts.

While the components of your diet — including the quality and quantity of protein you consume — play a major role in how rapidly and thoroughly your muscles grow in response to your exercise routine — the amount and quality of the rest you’re able to achieve is also a massive contributor to the repair of your muscles.

In addition to muscle repair, sleep also helps your body to maintain an optimal hormone balance, which is a vastly underrated benefit to preserving the functionality of your body. Perhaps the most obvious example of this is testosterone, which is critical to initiating muscle protein synthesis, maintaining bone density, and amplifying your metabolism to promote fat loss. 

Simply by failing to achieve adequate sleep on a regular basis, you can limit your body’s ability to produce testosterone, which can slow both fat loss and muscle gain all by itself. 

Finally, inadequate sleep can compromise your performance the following day, as your mind and body simply are not optimized to contend with the fatigue, discomfort, and pain that accompany demanding training sessions.

How Pre-Workout Ingredients Can Influence Sleep

Identifying precisely how pre-workout ingredients can ultimately influence your sleep quality would be a far more straightforward matter if there was only one component of a pre-workout capable of affecting your slumber. 

The fact is there are often three or more ingredients in every pre-workout formula that can play a direct or indirect role in altering your sleep pattern. Because of this, you’ll need to be mindful of these ingredients and what they do in your body, and also of the interplay between them. 

This awareness can help you determine if the potency of your pre-workout formula is too strong, or if you wouldn’t be better served by a low-stim or stim-free pre-workout option that is less aggressive.

Caffeine half-life and delayed clearance

Caffeine is the most popular stimulant in the world, and it boosts the alertness of your mind by blocking the ability of adenosine to bind to the receptors in your brain, which is what causes your body to perceive fatigue.

The half-life of caffeine is 4-5 hours, which means that half of the caffeine that you ingest will have exited your system in that time. This means if you’re training after work during the evening — hypothetically at 7:00 p.m. — and you chug a pre-workout shake just prior to your workout, more than half of the caffeine you consumed will still be active in your body by the time you lie down to sleep between 10:00 p.m. and 11:00 p.m.

Yohimbine and other stimulants and nervous system activation

Yohimbine and similar supplements like synephrine that work by stimulating receptors in your nervous system, and synephrine has been proven to increase the rate of fat oxidation during exercise. (8) These stimulants increase the release of norepinephrine — a neurotransmitter that triggers a fight-or-flight response in your body. 

Because these nervous system stimulators produce feelings of wakefulness by provoking your nervous system to act, they can make it quite challenging for your body to voluntarily calm down on command when you desire to sleep.

L-theanine, electrolytes, carbohydrates → supportive vs disruptive components

L-theanine is promoted as an amino acid that induces relaxation and improves focus without causing drowsiness. It accomplishes this by triggering your brain to increase its levels of dopamine, serotonin, and gamma-aminobutyric acid (GABA). Broadly speaking, L-theanine may help to improve sleep quality and mitigate the effects of some stimulants by inducing your mind to remain calm and focused. (9) Also, in non-stim pre-workout formulas, it can help you to focus without heavy stimulants.

Electrolytes play a vital role in regulating the central nervous system and preparing your body for restfulness. In particular, the electrolyte magnesium can be utilized to great advantage in achieving quality sleep due to its ability to lower core body temperature to a level conducive to sleeping, while also helping to relax your mind and muscles.

When it comes to everyday food selection, study results identify the quality of carbohydrates as a factor that contributes strongly to sleep quality. Study subjects who consumed high-quality carbohydrates (i.e. “whole grains, fruits, vegetables, and legumes”) were significantly more likely to experience high sleep quality than those who consumed low-quality carbohydrates (i.e., “added sugars, refined grains, fruit juices, and starchy vegetables”). (10)

Timing Guidelines: How Late Is Too Late?

Ultimately, it may seem like the decision of whether or not your habit of late-night training sessions that are performed in the aftermath of pre-workout intake are harming you is a matter of personal preference and tolerance. In some respects this is true, but in other respects it’s a simple matter of scientifically accounting for the ingredients involved. 

Also, you may not be fully aware of just how much your sleep quality and next-day performance will improve until you make some adjustments and test things out for yourself.

6–9 hour caffeine clearance range

When considering how long the pre-workout effects last, it is essential to understand the clearance range of caffeine. Because of caffeine’s clearance range of six to nine hours, you can rest assured that the restfulness of your body is in some way compromised by the presence of caffeine in your system. 

Therefore, consuming the high dose of caffeine present in most pre-workout servings will certainly hinder your sleep quality if it is consumed within six hours of your intended bedtime, and likely beyond that. This knowledge alone may make you desirous of a stim-free pre-workout formula, as the ingredient that is most likely to interfere with your sleep quality will not be present.

Night owls vs early risers

One of the most critical factors in identifying whether or not a late-night ration of pre-workout is detrimental to your sleep quality is how early in the morning you’re required to wake up. For instance, if you’re a night owl who happens to get the bulk of their work completed late at night and into the wee hours of the morning, a 7:00 p.m. gym workout that has been intensified by pre-workout is less likely to be detrimental to you if you had no intentions of falling asleep before 3:00 a.m. anyway, and aren’t due at class or work until noon.

On the other hand, if you’re an early-riser, consuming a fully-loaded pre-workout in the evening may have the effect of causing you to unnecessarily burn your candle at both ends by stripping you of hours of high-quality rest on a nightly basis.

Signs Pre-Workout Is Hurting Your Sleep

The fact that inferior sleep quality may be hindering your workouts may not be immediately apparent with respect to muscles that aren’t growing, or body fat that isn’t disappearing. All the same, there are a few telltale signs that should clue you into the fact that you’re suffering from a lack of sleep, or that you would do better to get a do better served to look for an alternative to a fully loaded pre-workout supplement prior to your evening workout.

The first sign is increased sleep latency, or the amount of time you spend awake in bed after lying down with the intention of sleeping. If you find that you’re unable to fall asleep despite your fervent desire to rest, this may be a sign that the caffeine in your system isn’t doing you any favors.

A second sign will be a high nighttime heart rate, which will usually be linked to high sleep latency if the cause of your accelerated heart rate is owed to the presence of stimulants rather than more serious matters like sleep apnea or hyperthyroidism. While this is not necessarily a major problem unto itself, it is a sign that you would probably be better served by not consuming pre-workout at such a late hour.

If you’re consistently groggy or weary early in the morning — at the time when your body is emerging from a state of peak restfulness —  this is probably a sign that you would benefit from less caffeine before bed, even if you perceive that you were able to achieve what you would usually consider to be adequate sleep in terms of the total number of hours you spent unconscious.

Finally, if you experience decreased HRV, or heart rate variability, it can be a sign of poor sleep quality, and is also a sign of overtraining in and of itself. In essence, the combination of pre-workout and evening training may be placing you in a situation where your body reacts like it has been chronically overtrained.

How to Use Pre-Workout Without Sacrificing Sleep

If you’ve performed a self-diagnosis and determined that you are clearly suffering from clear signs of compromised sleep, and you fear that your consumption of pre-workout is to blame, all is not lost. There are at least three things you can do to preserve your cherished practice of consuming pre-workout either before or during your training sessions.

Switching to low-stim or stim-free formulas

If you still want to exercise in the evening while taking a full dose of pre-workout, you can switch to a low-stim or stim-free pre-workout formula. Stim-free pre-workout benefits include a handful of ingredients that are intended to enhance blood flow and strength without the involvement of caffeine or other stimulants. 

In essence, if you’re already fully alert in the evening and simply need a boost to jumpstart your physical potential during your training session, minimizing or omitting the presence of stimulants can accomplish this without reducing your potential to achieve restfulness at night.

Reducing serving size

If you don’t want to completely forego the benefits of caffeine in your pre-workout supplement, you can simply choose to reduce the serving size of your pre-workout, essentially rendering it as a lower-stim variation by lowering the volume. The value of this method rests in the idea that by halving the amount of caffeine in your body, it will thereby reduce the amount of caffeine still in your system by half at the point when you’re ready to go to bed.

As straightforward as this sounds, there is a caveat to this, and it’s the fact that caffeine is said to induce supercharged benefits that measurably manifest themselves during workouts at doses of around 3-6 milligrams per kilogram of body weight. (11) This means that the peak benefits of caffeine are likely to elude you if you significantly cut your dose. Then again, if all you’re looking for is an elevated feeling of alertness during your workout, the additional benefits may not matter to you.

Pairing workouts earlier in the day when possible

If you desire to maintain the caffeine content of your pre-workout at boosted levels, your wisest course of option to avoid compromising sleep quality might be to simply move your workout to an earlier point in the day. This isn’t to suggest that you absolutely must do your training first thing in the morning, but if there’s an opportunity to slip out of work around noon and begin your training, the caffeine from your pre-workout should have fully exited your system by 10:00, which should certainly make it much easier for you to fall asleep.

When Pre-Workout Makes Sense—and When to Avoid It

Pre-workout is supposed to be a benefit to both your workout and your life. Adequate recovery is so essential to health and fitness that it is likely that whatever you are gaining by consuming a high-stim pre-workout supplement during the evening to boost your workout is being offset by the loss of restful sleep that results. 

If your sleep is clearly curtailed by evening consumption of pre-workout, please consider taking steps to adjust your training time, or manage your pre-workout intake in such a way that you don’t find yourself sacrificing quality sleep for the sake of a quality gym visit.

Sources:

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