If you have never taken pre workout before, you probably have questions. Maybe some nerves. You have heard stories about tingling skin and racing hearts and crashes that wipe out the rest of your day. You have seen people in the gym scooping powder into shaker bottles and wondered whether it is worth it, whether it is safe, whether it actually does anything.
Those nerves are completely normal. Everyone who has ever taken pre workout felt them the first time. But here is what I wish someone had told me before I took my first scoop: if you choose the right product, those nerves turn into excitement. Excitement at what the session is about to feel like. Excitement at the focus, the energy, the pump, the feeling of being completely locked into the work. Excitement at achieving things you never have achieved before.
Pre workout is a performance supplement designed to help you train harder, focus deeper and recover faster. That is the simple version. The complete version involves understanding what is actually inside the formula, how each ingredient works, what separates a good pre workout from a bad one, and how to use it properly so you get the benefits without any of the problems.
This is that complete version. Everything you need to know, from someone who has taken pre workout thousands of times across weightlifting, boxing, MMA, Muay Thai, BJJ and running, and who eventually built one from scratch because nothing on the market did everything it promised.
What Does Pre Workout Actually Do?
Pre workout supplements work by delivering a combination of ingredients that target different aspects of physical and mental performance. A properly formulated pre workout does five things simultaneously.
It increases energy and alertness through caffeine and other stimulants, allowing you to train with more intensity and less perceived effort. Research found that caffeine supplementation improved exercise performance by 2 to 16% across endurance, strength and power based activities. [1]
It improves blood flow and oxygen delivery to working muscles through nitric oxide boosters like L-Citrulline and beetroot extract, producing the "pump" that makes your muscles feel full and tight during training. A systematic review found that L-Citrulline at 6,000 to 8,000mg significantly improved strength endurance and reduced muscle soreness. [2]
It delays fatigue through buffering agents like beta alanine, which increases carnosine in muscle tissue and allows you to push through more reps and more sets before your muscles force you to stop. A meta analysis found significant improvements in exercise capacity with beta alanine supplementation. [4]
It sharpens focus and mind to muscle connection through nootropics like CDP Choline and L-Theanine, which support the neurotransmitters responsible for attention, motor control and calm alertness. Research found that CDP Choline improved cognitive performance and psychomotor speed. [3]
It enhances nutrient absorption through compounds like AstraGin, which ensures your body actually absorbs the ingredients at their full potential rather than passing a portion of them through unprocessed. [7]
When all five of these systems are working together at the right doses, the effect is not just physical. It is mental. You feel capable of more. The doubt that normally creeps in during hard sets gets quieter. The weight that intimidated you last week feels possible this week. That shift is not imaginary. It is the result of boosted dopamine, improved blood flow, sustained energy and enhanced cognitive function all arriving at the same time.
What Is Inside a Pre Workout?
Not all pre workouts contain the same ingredients at the same doses. The difference between a good pre workout and a bad one is almost entirely about what is inside and how much of it there is. Here are the key ingredients to understand.
Caffeine
Caffeine is the primary stimulant in most pre workouts. It blocks adenosine receptors in the brain, which reduces the perception of fatigue and increases alertness, energy and reaction time. [1]
The important thing is not just how much caffeine but what type. Most pre workouts use caffeine anhydrous, which is fast acting and hits within 15 to 30 minutes. The problem is that it peaks within 45 to 60 minutes and then declines, leaving you with less energy in the second half of your session.
A dual caffeine system combines caffeine anhydrous with di-caffeine malate, which absorbs gradually and sustains energy for significantly longer. Research found that sustained release caffeine maintained performance without the crash associated with single source formulations. [8] For a full breakdown of how these two types of caffeine work differently, read our guide to caffeine anhydrous vs di-caffeine malate.
BigDaddy uses 250mg caffeine anhydrous and 200mg di-caffeine malate. 450mg total through a dual system. That makes it the highest caffeine dual source pre workout in the UK.
L-Citrulline
L-Citrulline is an amino acid that converts to arginine in the kidneys, driving nitric oxide production. Nitric oxide widens blood vessels, increases blood flow to working muscles and produces the pump that makes training feel productive and look impressive. [2]
The clinical dose is 6,000 to 8,000mg of pure L-Citrulline. Many pre workouts use citrulline malate instead, which is roughly 60% citrulline and 40% malic acid by weight. A label that says "6,000mg citrulline malate" is actually delivering roughly 3,600mg of real citrulline. Read labels carefully.
BigDaddy contains 8,000mg of pure L-Citrulline. No malate filler. The full clinical dose.
Beta Alanine
Beta alanine increases carnosine concentrations in muscle tissue. Carnosine buffers the hydrogen ions that cause the burning sensation during high intensity exercise. More carnosine means you can push through more reps before your muscles force you to stop. [4]
The effective dose is 3,200 to 3,500mg per serving. Beta alanine causes a harmless tingling sensation in the skin called paresthesia. If you feel it, the dose is high enough to work. If you do not, it is probably underdosed.
BigDaddy contains 3,500mg.
CDP Choline
CDP Choline is a nootropic that acts as a precursor to acetylcholine, the neurotransmitter responsible for attention, focus and muscle contraction. It produces genuine mental clarity and sharpens the mind to muscle connection. [3]
This is the ingredient most pre workouts skip entirely because it is expensive. The popular ones like ABE use cheaper, less bioavailable forms of choline at lower doses. If you have ever taken a pre workout that promised focus but just made your heart race, the missing CDP Choline is probably why.
BigDaddy contains 800mg. For a detailed comparison of how this affects the experience versus ABE, read our BigDaddy vs ABE breakdown.
Beetroot Extract
Concentrated beetroot extract provides dietary nitrate, which the body converts to nitric oxide through a completely different pathway than L-Citrulline. Research found that beetroot supplementation improved exercise efficiency and extended time to exhaustion. [5]
When you stack beetroot alongside citrulline, the two pathways compound. The result is significantly better blood flow and pump than either ingredient produces alone. BigDaddy contains 2,000mg of RedNite concentrated beetroot extract alongside 8,000mg of L-Citrulline. Two nitric oxide pathways. Both fully loaded.
L-Theanine
L-Theanine is an amino acid found in green tea that promotes alpha brain wave activity, the brain state associated with calm, focused alertness. When combined with caffeine, research found that it significantly improved attention and reduced jitteriness. [6]
This is the ingredient that separates jittery, anxious energy from smooth, controlled focus. Without it, high caffeine pre workouts make you wired but scattered. With it, you are locked in.
BigDaddy contains 350mg. Most pre workouts that include L-Theanine underdose it at 100 to 200mg, which is not enough to smooth out a high caffeine formula.
AstraGin
AstraGin increases the absorption of amino acids and other nutrients in the gut. [7] It makes every other ingredient in the formula work harder. Most brands skip it. BigDaddy includes it because there is no point formulating a product at clinical doses if your body only absorbs a fraction of them.
How to Read a Pre Workout Label
Not all pre workouts are transparent about what is inside. Here is what to look for and what to avoid.
Look for full ingredient disclosure. Every ingredient should have its dose listed individually on the label. If you see the phrase "proprietary blend" followed by a total weight and a list of ingredients without individual doses, the manufacturer is hiding how much of each ingredient you are actually getting. The caffeine could be 400mg or it could be 100mg. You have no way of knowing. Do not buy products that hide their formulas.
Check the citrulline form. Pure L-Citrulline and citrulline malate are not the same thing. Citrulline malate is roughly 40% malic acid by weight. A product claiming 6,000mg of citrulline malate delivers about 3,600mg of actual citrulline. A product with 8,000mg of pure L-Citrulline delivers exactly that. The label tells you which one you are getting if you know what to look for.
Check the caffeine source. If only caffeine anhydrous is listed, all the caffeine hits at once and crashes. If both caffeine anhydrous and di-caffeine malate are listed, the formula uses a dual system with sustained release. The second option is significantly better for longer sessions.
Check for L-Theanine. If the caffeine dose is above 300mg and there is no L-Theanine in the formula, expect jitters. The higher the caffeine, the more important L-Theanine becomes.
Look at the price per serving, not the price per tub. A £25 tub with 20 servings costs £1.25 per scoop. A £29 tub with 36 servings costs roughly 80p per scoop. The cheaper tub is actually more expensive.
Does Pre Workout Actually Work?
Yes. The individual ingredients in a properly formulated pre workout are among the most well researched performance supplements in sports science.
Caffeine improves exercise performance by 2 to 16%. [1] L-Citrulline at clinical doses improves strength endurance and reduces muscle soreness. [2] Beta alanine improves exercise capacity in efforts lasting 1 to 4 minutes. [4] CDP Choline improves attention and psychomotor speed. [3] Beetroot nitrate improves exercise efficiency. [5]
The key word is "properly formulated." A pre workout with 150mg of caffeine, 2,000mg of citrulline and a proprietary blend does not have enough of anything to produce a meaningful effect. A pre workout with 450mg of dual caffeine, 8,000mg of pure citrulline, 3,500mg of beta alanine and 800mg of CDP Choline has enough of everything to produce the effect the research describes.
Most people who say "pre workout does not work" have only tried underdosed products. They never experienced what a clinically dosed formula actually does because the mainstream products they tried were never formulated to deliver it.
Pre Workout Side Effects and How to Manage Them
Pre workout is safe for most healthy adults when used as directed. But there are side effects to be aware of, particularly if you are new to supplementation.
Tingling skin (paresthesia). Caused by beta alanine. Completely harmless. It is a sign that the dose is high enough to be effective. It typically fades within 20 to 30 minutes and diminishes with regular use as your body adapts.
Jitteriness or anxiety. Usually caused by too much caffeine without enough L-Theanine, or by taking pre workout on an empty stomach. Start with half a scoop to assess tolerance. A formula with a proper L-Theanine dose (300mg or more) significantly reduces this.
Sleep disruption. Caffeine has a half life of approximately 5 hours. Do not take pre workout within 6 hours of bedtime. If you train in the evening, consider a lower caffeine option or a stimulant free formula.
Stomach discomfort. Can occur at high caffeine doses, particularly on an empty stomach. Eating a small meal 60 to 90 minutes before taking pre workout helps. Di-caffeine malate is generally gentler on the stomach than caffeine anhydrous because the malic acid buffers the acidity.
Crash. The single most common complaint about pre workout. This is almost always caused by single source caffeine that spikes and drops. A dual caffeine system eliminates this by sustaining energy levels rather than spiking and crashing. BigDaddy was specifically designed to produce zero crash.
If you have cardiovascular conditions, high blood pressure or caffeine sensitivity, speak to your GP before using any pre workout.
When to Take Pre Workout
Take it 25 to 35 minutes before training starts. This gives the caffeine anhydrous time to reach your bloodstream and the other ingredients time to begin absorbing.
For heavy compound sessions like squats and deadlifts, lean towards 35 minutes so the caffeine has peaked by the time you reach your heaviest working sets. For lighter or higher volume sessions, 25 minutes is fine.
Do not take it more than 45 minutes before training. The caffeine anhydrous component will have peaked and begun declining by the time you start, wasting the fast acting portion of the formula.
Do not double scoop. The ingredients are dosed at clinical levels for one scoop. Taking two does not double the benefit. It doubles the side effects.
Pre Workout for Different Sports
Pre workout is not just for the gym. A well formulated product benefits any physical activity that demands energy, endurance, focus or blood flow.
Weightlifting. Sustained energy across a 60 to 90 minute session, pump that compounds through working sets, focus that sharpens the mind to muscle connection. Read our full guide to pre workout for weightlifting.
Boxing. Cold, controlled focus without the anxious edge. Energy that lasts from round one to round eight. The ability to stay sharp mentally when fatigue tries to scatter your technique. Read our full guide to pre workout for boxing.
MMA. Explosive power, sustained grappling endurance and the cognitive clarity to make decisions under pressure. Read our full guide to pre workout for MMA.
Muay Thai. The combination of striking power and clinch endurance demands both the fast acting caffeine for explosive movements and the sustained release for later rounds. Read our full guide to pre workout for Muay Thai.
Running. Sustained energy that does not spike and crash mid run. Improved oxygen delivery through dual nitric oxide pathways. Mental focus that stops you from quitting before your body actually needs to. I hated running. Could not finish a 5k. The first time I took BigDaddy before a run, I completed the whole thing. My legs did not change overnight. My mind did. Read our full guide to pre workout for running.
Football and rugby. Energy that lasts 90 minutes without fading in the second half. Endurance support for repeated sprints. Focus for decision making under fatigue. Read our full guide to pre workout for football and pre workout for rugby.
How to Choose the Right Pre Workout
If you are choosing your first pre workout or looking to switch from something that has not been delivering, here is what to prioritise.
Check that the label is fully transparent with every dose listed. Check that the citrulline is pure L-Citrulline at 6,000mg or above, not underdosed citrulline malate. Check that the caffeine uses a dual system for sustained energy. Check that L-Theanine is included at 200mg or more to smooth the caffeine. Check for a genuine nootropic like CDP Choline, not just a cheap choline filler. Check the price per serving, not the price per tub.
If this is your first time, start with half a scoop to assess your tolerance and build from there. For a full guide on getting started safely, read pre workout for beginners.
For a comparison of the most popular UK pre workouts against these criteria, read our best pre workout UK guide. For the strongest options, read strongest pre workout UK.
Frequently Asked Questions
What is pre workout? Pre workout is a performance supplement taken before training to increase energy, improve blood flow, delay fatigue, sharpen focus and enhance overall athletic performance. It typically comes as a powder mixed with water and consumed 25 to 35 minutes before exercise. The best pre workouts contain clinically dosed ingredients like caffeine, L-Citrulline, beta alanine, CDP Choline and L-Theanine.
Is pre workout safe? For healthy adults, yes. Start with half a scoop to assess tolerance. Avoid within 6 hours of sleep. Do not combine with other caffeine sources. Consult a GP if you have cardiovascular conditions or caffeine sensitivity. Side effects like tingling skin and mild jitteriness are normal and manageable.
Does pre workout actually work? Yes. The ingredients in a properly formulated pre workout are among the most well researched supplements in sports science. Caffeine improves performance by 2 to 16%. L-Citrulline improves blood flow and endurance. Beta alanine buffers fatigue. CDP Choline sharpens focus. The key is dosing. Underdosed products produce little effect. Clinically dosed products produce measurable results.
Why does pre workout make your skin tingle? The tingling is called paresthesia and it is caused by beta alanine. It is completely harmless and is actually a sign that the dose is high enough to work. The sensation fades within 20 to 30 minutes and diminishes with regular use.
Can you take pre workout every day? Yes, for most healthy adults. However, cycling off for one week every 6 to 8 weeks helps maintain caffeine sensitivity and ensures the product continues to feel effective. Save it for your hardest training days and consider skipping it on deload weeks or rest days.
When should you take pre workout? 25 to 35 minutes before training. This gives the ingredients time to absorb and reach effective levels in your bloodstream. Do not take it more than 45 minutes before training or the fast acting caffeine will have peaked before you start.
How long does pre workout last? Single source caffeine pre workouts typically last 45 to 60 minutes of peak effect. A dual caffeine system like BigDaddy's sustains energy for 90 minutes or longer because the di-caffeine malate releases gradually after the caffeine anhydrous peaks.
What happens if you take pre workout and do not work out? You will feel the stimulant effects (energy, alertness, potentially tingling) but the performance ingredients that require physical exertion to be useful (citrulline for pump, beta alanine for endurance) will not deliver their benefits. It is not dangerous but it is a waste.
What is the best pre workout in the UK? The best pre workout in the UK is the one that delivers clinical doses of every key ingredient, uses a dual caffeine system for sustained energy, includes CDP Choline for genuine focus, runs dual nitric oxide pathways for pump, and does all of this at a fair price with full label transparency. BigDaddy meets every one of those criteria. 450mg dual caffeine. 8,000mg L-Citrulline. 2,000mg RedNite. 800mg CDP Choline. 350mg L-Theanine. £29. 36 servings.
The Research
[1] Caffeine and exercise performance: https://pubmed.ncbi.nlm.nih.gov/19088794/ [2] L-Citrulline at clinical doses: https://pmc.ncbi.nlm.nih.gov/articles/PMC10366749/ [3] CDP Choline and cognitive performance: https://pubmed.ncbi.nlm.nih.gov/33978188/ [4] Beta Alanine and exercise capacity: https://pubmed.ncbi.nlm.nih.gov/27797728/ [5] Beetroot nitrates and endurance: https://pmc.ncbi.nlm.nih.gov/articles/PMC5295087/ [6] L-Theanine and caffeine combination: https://pmc.ncbi.nlm.nih.gov/articles/PMC4480845/ [7] AstraGin and nutrient absorption: https://pubmed.ncbi.nlm.nih.gov/29614961/ [8] Sustained caffeine delivery: https://pubmed.ncbi.nlm.nih.gov/29876876/
The Summary
Pre workout is not magic. It will not replace bad sleep, poor nutrition or an inconsistent programme. But when those foundations are in place and you add a formula that is built properly, something shifts. Not just in your body. In your belief about what your body can do.
The first time you train on the right pre workout, the nerves you had about trying it will turn into excitement. Excitement at the energy that stays. Excitement at the pump that compounds. Excitement at the focus that makes the gym go quiet. And excitement at the moment you achieve something you never have achieved before.
That is what pre workout is. Not a powder in a tub. A belief that the next session could be the best one yet.
BigDaddy Pre Workout. 450mg dual caffeine. 8,000mg L-Citrulline. 2,000mg RedNite. 800mg CDP Choline. 350mg L-Theanine. 36 servings. £29. The nerves turn into excitement.