The Truth About Pre-Workout Supplements


You’ve probably heard a lot of people talking about a taking a ‘pre-workout’ before the gym. You might even take one yourself. But the big question is this: do they actually work or are you just wasting your cash?

do pre-workout supplements work

A pre-workout is type of supplement that folks take around 30-40 minutes before hitting the gym. They have sexy titles that sound intense like C4 Ripped, No-Explode and Assault. The reported benefits are enhanced training performance and improved training adaptions like increased muscle gain and faster recovery. Sounds great, right? But are these claims actually legit?

A note on Proprietary Blends

Before we can go any further into the realms of pre-workouts, you need to understand what a ‘proprietary blend’ is. It’s important because a lot of pre-workout supplements include some kind of blend.

Unfortunately, this isn’t a good thing!  It is a sneaky trick the supplement companies like to use. They give these mixes snazzy titles like “fat ignition blend”, “mass power blend”, “focus ignition” etc. They have to tell you what ingredients they put in the blend but they don’t need to tell you how much. That means they can say their blend includes creatine, beta-alanine, caffeine etc but there might only be trace amounts in it. Not cool.

what are proprietary blends?

Would you ever buy something in the supermarket, let’s say a steak, without knowing how much steak was in the packet? It could be a 1kg monster or it could be like a morsel of mince. No, of course you wouldn’t, so don’t do this with your supplements either.

Proprietary blends could even be harmful. Would you want to be taking a supplement with no idea of how much caffeine is in it? I certainly wouldn’t.

If you see a pre-wo that includes some form of proprietary blend on the label, avoid it like curls in a squat rack.

The Main Ingredients In Pre-Workouts

Ok, aside from a few dodgey proprietary blends, here are some of the main ingredients found in most pre-workout supplements.


One of the main ingredients in an all-in-one pre-workout supplement is caffeine. Coffee anyone? Numerous studies have shown that caffeine affects perceived exertion and can minimize fatigue. This can be a winner if you train first thing in the morning or you hit the gym after a slog of an 8 hour day in the office.

I analysed of the 10 most popular pre-workout blends on and found that the caffeine content ranged from 150 mg to 300 mg.

how much caffeine in pre-workout supplements

In the majority of studies that support the use of caffeine before a workout, the recommended dose is around 3-6mg per kg of bodyweight. That means that 300mg of caffeine could be a shit-load of caffeine if the person taking that pre-workout has a relatively low body weight.

Caffeine is also one of the cheapest ingredients found in pre-workouts. This perhaps explains why many of the brands like to include it in quite high doses, in their formulas.


Creatine monohydrate is often found in pre-workouts and it’s been shown to increase lean body mass, power and strength. Of the 10 most popular all-in-one formulas I examined, only 4 used creatine monohydrate. The remaining 6 listed a proprietary blend or included creatine hydrochloride or creatine nitrate, which has been shown to be less effective.

But here’s the deal.

It doesn’t really matter when you take creatine. You can take it before a workout, after a workout, with breakfast after you’ve brushed your teeth…it doesn’t matter. You’ll get the benefits of using creatine regardless when you use it.


Muscular Man With Strong Muscles Drinking Protein Shake In Kitchen, Best Supplements

BCAAs (Branch Chain Amino Acids), another popular ingredient in pre-workout formulas. They have been shown to positively impact body composition, support immune function and reduce markers of muscle damage. Sounds good, right?

However, the main study that supplement companies use to support the use of BCAAs has a few flaws. The main one being that the protein intake per day for the calorie-restricted subjects was ~1.2g/kg. I know what you’re thinking, this is pretty low!

More recent studies suggest that protein needs during a diet phase in lean folks may be considerably higher, at ~2.3-3.1g/kg/bw. This means that if you eat enough protein, it’s unlikely that BCAAs are going to do anything for you!

A recent review published in 2016 also concluded that there doesn’t seem to be a benefit to BCAA supplementation during periods of caloric restriction.


Several studies have shown that beta alanine may be beneficial to those engaging in resistance training. In one 30-day study, around 5g per day of beta-alanine improved muscular endurance during a resistance training workout. Sounds promising?

However, here’s the kicker.

Most of the pre-workout blends skimp on the beta-alanine! Of the most popular 10 pre-workout blends, 7 included beta-alanine ranging from 23% to 41% of the dose used in research. Meaning, there’s hardly enough in the formula to make much of a difference.

Secondly, like creatine, due to the way beta-alanine works, it’s not timing-dependent, so it doesn’t need to be consumed pre-workout. You get the benefits of beta-alanine regardless of when you take it.

Here’s my theory.

The reason why beta-alanine is included in so many pre-workouts formula is because it induces something called paresthesia. Aka pins and needles. If you’ve ever take it before you’ll know the feeling.

Although the paresthesia has no benefits, the physical tingling sensation felt by folks who take it may contribute to the perception that pre-workouts improve training performance in the sense that they can ‘feel’ the pre-workout having an effect.

Seems like a bit of a swizz if you ask me

Citrulline Malate

Citrulline malate is often included in pre-workout blends. One study found that 8g/d of Citrulline may increase athletic performance in high-intensity anaerobic exercise; yet other studies show it does not reduce time to exhaustion nor does it increase muscle protein synthesis.

Of the 10 all-in-one formulations examined, dosages varied considerably. 3 products did not include it, 3 included it as part of a proprietary blend and of the remaining 4, the dose ranged from 19%-75% of the research dose.

Therefore, for the majority of gym users who take an all-in one formula, they are unlikely to experience any benefits of Citrulline even if the supplement label say it’s included.


arginine pre-workout

Arginine is an ingredient often found in pre-workouts that is unlikely to make any difference to your workout. It reportedly increases levels of nitric oxide resulting in increased blood circulation (commonly known as the “pump”) and therefore in greater oxygen delivery and exercise efficiency.

This sounds good, but numerous studies demonstrate that increased nitric oxide does not actually lead to improved exercise performance. Oh dear.

Another thing is that when you take arginine orally, it’s not very bioavailable. This means that very little of it actually enters your blood stream to have any effect.


Glutamine is another that you’ll often find. But it has no significant effect on exercise performance, body composition or attenuation of muscle protein degradation…..woops.

The Bottom Line

Pre-workout supplements can give you a buzz but this is largely down to the caffeine content.

The doses of all the other ingredients, that may have an effect (beta-alanine, citrulline etc), are usually so low that you’re unlikely to get any benefit from them. The pre-wos are often filled with other ingredients that aren’t going to make the slightest difference to the quality of your workout.

If you are looking to try and get an edge and improve your own workout, it would be much more cost effective to just have a coffee instead. Most medium coffees from Starbucks/Costa etc have around 200mg per cup. If you’re not a coffee-drinker then a caffeine supplement may be your best bet.

Creatine and beta-alanine are beneficial too but there isn’t any need to take them before a workout. Beta alanine can be taken at any time of day, just like creatine. To learn more about the best type of creatine, how much to take and when, read this article.

By using the individual ingredients, rather than a blend, you can tailor the dosage to your own goals, weight, needs and tolerances. You’re not going to be taking any garbage that doesn’t work. You’re at less risk of taking contaminated substances and it’s also going to save you quite a few quid too!

But the main thing is that there is still no substitute for hard work, a solid training plan and a proper nutrition routine. Supplements may make a little difference but unless you’ve nailed the first three then any cash you splash on pills and powders is likely to be an exercise in futility.

do pre-workout supplements work?

Scott is the owner and founder of Food For Fitness. He is a fat loss coach, speaker and fitness writer with a masters (MSc) degree in Applied Sports Nutrition.