Pre-Workout: What You Need to Know

Pre-workout supplements are designed to be taken before exercise with the aim of boosting energy, focus, and performance. Most of their effect comes from caffeine, with some formulas also providing carbohydrates and other active ingredients. Whether they're worth it depends on your goals and how you train.

What Is Pre-Workout?

Pre-workout is the term for a dietary supplement designed to be taken before exercise (usually 30–60 minutes prior to a high-intensity workout) with the aim of enhancing performance. They claim to improve focus, increase energy and delay fatigue during training through the inclusion of stimulants like caffeine, along with active ingredients designed to help improve motivation and promote recovery.

Sounds great, right? With that promise of boosting performance, alongside the rise of fitness social media, pre-workouts have gained a lot of popularity in recent years. They have actually been around since the 80s, when "Ultimate Orange" was created for bodybuilders. Over the past twenty years they have become more common with the everyday gym-goer, meaning the market has become saturated with a range of products.

These "pre-workouts" mostly come in powder form to mix with water, but you can also get pre-workout chews, bars, capsules and pre-mixed cans.

What Does Pre-Workout Actually Do?

Most pre-workouts claim to boost energy, focus and physical performance during your workout.

Designed to be taken 30–45 minutes before your session, this allows caffeine (a common ingredient in most pre-workouts) or other stimulants time to peak in your bloodstream before you start exercising. Taking it on an empty stomach can lead to quicker absorption and stronger results (although fasted training comes with its own risks).

The primary effect most users report is increased energy and alertness, largely thanks to the caffeine and other stimulants. Caffeine is one of the most studied "boosters", and numerous studies show that consuming it in a timely manner when exercising can reduce perceived effort, meaning exercise feels less hard despite working at the same intensity.

A significant portion of the performance boost may actually be psychological. That simple ritual of taking something before training can increase how motivated and ready to train you feel. Placebo can be really powerful: a 2024 review published in MDPI found that simply believing you've taken a performance-enhancing supplement can meaningfully improve motor performance. ⊕ ⊕ ⊕

Studies also show that stimulants like caffeine can modestly improve your endurance and power, but the effects are strongest in those who don't typically consume caffeine. For those of us drinking three cups of coffee a day who have built a tolerance, we might not feel the same benefits.

What's Inside Pre-Workout Supplements?

Caffeine

Caffeine is the backbone of almost every pre-workout formula, and for good reason. It's also the ingredient with the most evidence to suggest it actually works. It is found to delay fatigue, reduce the level of perceived exertion and improve reaction time. Most notably, though, it is thought to improve endurance performance by 2–5%.

Most formulas contain around 150–400mg of caffeine. This is quite a bit more than even a strong black coffee, which is usually 80–120mg. It works by blocking adenosine receptors—the sleep drive—in the brain. This makes you feel more awake and alert, and hopefully more motivated and able to train too.

Caffeine is widely used in sport at all levels, from trying to wake yourself up on the way to an early workout class to elite-level athletes utilising caffeinated sports nutrition to boost performance. Since its removal from the World Anti-Doping Agency list of banned substances in 2004 (hard to believe it was ever on there!), around 76% of athletes from various sports were found to have consumed caffeine prior to or during sporting events.

Carbohydrates

Many pre-workouts include a dose of fast-digesting carbs like glucose, maltodextrin and dextrose. These give you a quick top-up of glycogen stores—especially handy for early morning workouts or those who struggle to eat before exercising.

The carb content varies hugely between different formulas and brands. Some contain 20–30g per serving (similar to a banana), while others have zero.

Carbohydrates are probably one of the most effective pre-workout "supplements", and certainly one of the most studied. ⊕ Glycogen (your body's store of carbohydrates) is our major fuel source during moderate- to high-intensity exercise. Carbohydrates help you maintain performance throughout exercise, delay fatigue, and support training volume and intensity.

Beta-Alanine

Ever heard that pre-workout makes you feel "tingly" or itchy? Well, that's the beta-alanine at play. Beta-alanine is a non-essential amino acid that combines with another amino acid, histidine, in your muscles to form carnosine. This helps buffer the build-up of acid during intense exercise and can delay muscle fatigue. It's most relevant to workouts that include short, intense bursts of exercise, such as HIIT workouts, sprints, intervals and moderate/high-rep weightlifting, rather than max-effort lifts and endurance efforts.

It doesn't act as an immediate stimulant and is actually most beneficial when taken regularly to build up muscle carnosine levels.

Creatine

Creatine helps your body regenerate ATP, the body's primary source of quick energy. This helps you lift heavier weights, increase reps and improve sprint and explosive performance, as well as increase strength and muscle over time in combination with regular training.

Creatine is another supplement included in most pre-workouts with a decent amount of evidence behind it. However, it's also one that is most beneficial when taken daily, and therefore may not add much to a pre-workout.

An effective dose of creatine is 3–5g per day; some pre-workouts contain this amount but many don't, so gym-goers may supplement this separately.

Citrulline

Citrulline is a potentially useful, non-stimulant addition to pre-workout. Whilst there isn't as much evidence to support the inclusion of citrulline as there is for caffeine, there is promising research for its use in increasing nitric oxide production, helping widen blood vessels and therefore potentially increasing blood flow to working muscles. This could translate into a few extra reps or lower fatigue in high-volume workouts.

However, a lot of pre-workouts include less than the research-backed dosage for performance enhancement, which may reduce its effectiveness.

BCAAs

BCAAs are three essential branched-chain amino acids: leucine, isoleucine and valine. They are commonly added to pre-workout due to their role in muscle protein synthesis and energy metabolism. Evidence for their acute effectiveness is still limited, and those who eat sufficient protein in their diet probably get enough naturally.

Do You Really Need Pre-Workout?

The honest answer for the majority of us is: no, you probably don't need it.

Pre-workout is more of an "icing on the cake" scenario. While it can have some benefits, the fundamentals—consistent training, getting enough sleep, quality nutrition—have a much bigger impact than any supplement, with far more evidence to back them up.

And really, the benefits you can get from pre-workout formulas could also be gained by having caffeine and carbs, like a strong coffee and a banana before you head to the gym, and regularly taking a creatine supplement.

Context is important too, though. If you're just doing a couple of low-intensity workouts each week and eat well in between, you probably don't have much to gain from a pre-workout. But if you're training more intensely, doing multiple sessions per day and often in a depleted state, then the convenience of a pre-workout may be worth it.

Coffee vs Pre-Workout: What's the Difference?

The main ingredient in pretty much all pre-workout formulas is caffeine. Studies have compared coffee to caffeine anhydrous, the synthetic form used in supplements, and have shown similar performance outcomes. ⊕

A pre-exercise caffeine intake of 2–6mg per kg of body mass seems to show improved performance—which is the same as 1–2 cups of strong coffee. That may seem a lot for some people, or just a normal morning's intake for others!

The main advantage of pre-workout over coffee is the precise dosing; you know exactly how much caffeine you're getting. You do also get those additional ingredients like beta-alanine and creatine, but as mentioned above, these can be of limited benefit. Coffee, on the other hand, is cheaper, widely available and (usually) doesn't come with any mysterious additives.

However, both need to be consumed with caution if you're not used to caffeine, as too much can give you the jitters, cause feelings of anxiety, gastrointestinal distress and impact sleep.

What to Eat Before a Workout Instead

Carbohydrates: carbs are generally much more impactful than any supplement; our muscles need glycogen to work. Try a banana, a bowl of cereal or other quick-release carbohydrates about an hour before your workout. If you have less time, a sports drink, juice or other carb drink works well for quick absorption. Any larger meals should ideally be consumed 2–3 hours before working out.

Coffee or other caffeinated drink: whether you prefer a double shot of espresso, an energy drink or matcha, consuming caffeine 45–60 minutes before your workout can help delay fatigue, boost performance and make you feel more alert.

Hydration: if you're looking to improve performance, hydration is a key component. Dehydration impairs both physical and cognitive performance by up to 10% or more, according to studies. ⊕ Try to have 500ml of water in the 1–2 hours before training, and take on more during the session as needed. Electrolytes can be useful for longer sessions (anything over 90 minutes), or when working out in hot climates. Hydration needs are highly individualised, and sweat tests can help those wanting to focus on performance to create personal hydration plans (usually most useful for endurance activities).

Protein: depending on your goals, pre-workout protein in combination with carbohydrates can support muscle growth. However, overall daily protein intake matters most.

When Pre-Workout Might Make Sense

Is pre-workout essential? No. It can give you an extra advantage—but it's definitely not something that can replace getting the basics right.

It's most useful for athletes wanting to perform at the top of their game (even if that's just recreationally), who have already got their sleep, training and nutrition dialled in and are looking for more marginal gains. Or for those wanting to experiment with the "additional extras" found in many pre-workout formulas, like BCAAs and citrulline, without having to take a whole range of supplements.

It may be worth saving it for particularly demanding sessions rather than habitually using it if you want to feel the physical benefits. And don't forget to hold back on caffeine elsewhere in the day to avoid the jitters!

Some people find value in the ritualistic/placebo element, though, which—as the studies show—does have some merit.

For the less competitive amongst us, you might find pre-workout useful for early morning training sessions where an easy hit of carbs and caffeine is the most convenient, on-the-go option.

Are There Downsides to Pre-Workout Supplements?

There are some reported downsides of pre-workout. These include:

Overstimulation: high-caffeine products (particularly those above 300mg) can cause anxiety, jitters, a high heart rate and nausea. You might especially find this if you're not used to caffeine and suddenly take a high dose! This can put stress on the cardiovascular system.

Tingly/itchy skin: many report feeling tingly or itchy after taking pre-workout, thanks to the beta-alanine content. It is harmless, but some may find it uncomfortable or unpleasant.

Sleep disruption: caffeine has a half-life of 4–6 hours. This means that if you normally work out in the evening, it will still be active in your system at bedtime. A 2025 study showed that even a moderate amount of caffeine consumed 6 hours before bedtime reduced total sleep time by 41 minutes. ⊕ So the thing you're taking to support your workout might actually get in the way of one of the much more effective fundamentals for supporting performance. It may also mask feelings of fatigue—your body's natural signal to slow down and prioritise recovery.

Nutrition: relying on pre-workout for energy may just treat the symptoms rather than the cause of the problem, which could be under-fuelling, poor meal timing or inadequate nutrition. Some products also contain higher levels of sugar than more natural alternatives.

The Bigger Picture: What Actually Improves Performance

Sleep: one of the most powerful tools we've got, and completely free if we can make time for it! Stanford University studied elite basketball players and found that their shooting accuracy, sprint times and reaction times all improved with more sleep. ⊕ 7–9 hours per night is the sweet spot for most adults, however many elite athletes require 9–10 hours per night to recover from heavy training loads.

Nutrition: the actual breakdown of your diet and supplements may differ depending on your goals, however the fundamentals don't change. Adequate protein to support your needs (typically 1.2–2g/kg per day) on a daily basis. Carbohydrates to fuel your workouts and bodily functions. Healthy fats to support hormone production and vitamin absorption. Supplements can be an addition once you've got the nutrition basics covered—and for long-term, foundational support, a consistent daily nutrient base can be more valuable than any single pre-workout hit.

Consistency: consistency is key, both in terms of training and to reap the rewards of certain supplements. Creatine has been widely researched, with evidence supporting its use for improving gym performance when taken daily to saturate the muscles. Beta-alanine is also most effective when taken regularly.

Recovery: whilst sleep is arguably the most important recovery tool in our arsenal, recovery can also include sufficient nutrition and hydration, rest days, de-load weeks and stress-relieving activities that allow improvements in performance.

Final Thoughts: Keep It Simple

The key takeaway is that pre-workout is optional, but definitely not essential. It does have some recorded benefits, but these are mostly available in other (often more cost-effective!) forms, such as coffee or natural foods, or supplements that are most beneficial when taken daily.

Taking pre-workout definitely isn't something you should prioritise over the fundamentals, like sleep, adequate nutrition and hydration, which offer many more evidence-based advantages as well as overall health benefits.

If you like pre-workout and it fits your budget, then it's not harmful (in moderation), but it's definitely a finishing touch rather than a shortcut.