Pre-workout supplements are widely used among recreational gym goers who swear by their effectiveness at improving performance. But are pre-workout supplements actually effective at improving performance in the gym, or are they just expensive caffeine?
What did they test? The authors reviewed and meta-analyzed the current literature to explore the effect of commercially available pre-workout supplements on strength, training volume, and anaerobic capacity in trained individuals.
What did they find? Overall, pre-workout supplements resulted in some increases in strength and training volume completed, although results were mixed, and the quality of available evidence was low.
What does it mean for you? Pre-workout supplements may aid in some resistance training performance improvements, mostly due to their caffeine content, but are nothing special.
What’s the Problem?
Pre Workout supplements are among the most hyped and (ab)used supplements on the market. From the glorious days of the now-banned classics Jack3d and Craze to the infamous underdosed pre-workout formulas hiding their ingredients in proprietary blends all the way to today’s more honest supplements, pre-workout supplements have received a lot of attention from the fitness community and the mainstream media. There was even a trend on TikTok where people would “dry scoop” their pre-workout supplements, i.e., drink them without mixing them with water first, a trend that was quite dangerous and was also covered extensively in mainstream media with several articles and videos on why you should NOT follow said TikTok trend.
But let’s take a step back and look at what exactly pre-workout supplements are. For those that are unaware, pre-workout supplements are meant to have an acute effect on your training, usually via the inclusion of stimulants like caffeine, to improve energy, focus, and concentration. Pre-workout supplements boomed in the fitness industry in the early 10s, with people often finding themselves building a tolerance to the very high caffeine of some of these products as a result of taking them very frequently. Currently, the pre-workout supplement accounts for approximately 20% of global sales in the supplements industry, with its current market value estimated to be around 14 billion USD, and projected to be around 31 billion USD in the next 10 years or so 1.
The hype around pre-workout supplements probably stems from the acute effect that they can have on performance or at least on the perception of performance, as we will discuss later. Caffeine is known to have an ergogenic effect on resistance training performance, and pre-workout supplements usually contain plenty of it, with some going as high as 500mg, roughly what you’d get from downing 5 cups of coffee. Pre-workout supplements also contain many other ingredients that are supposedly beneficial for exercise performance, muscle strength, muscle endurance, and even things like “the pump,” as Arnold would say.
I used the word “supposedly” as some of these ingredients are not backed by much scientific literature in terms of their effectiveness for boosting exercise performance (e.g., l-arginine 2), and others do not have an acute effect and need to be taken for a while to “accumulate” in the body and be effective (e.g., creatine monohydrate). Other ingredients that were very popular among some of the first pre-workout supplements, and still present in some, are now on the list of banned substances by the World Anti-Doping Agency (e.g., 1,4-Dimethylamylamine aka DMAA). The FDA has minimal control over approving pre-workout supplements, which has often resulted in manufacturers selling underdosed products via “proprietary blends,” essentially disclosing the total amount of ingredients via a blend of multiple ingredients, but without mentioning the exact amount of each ingredient.
An example from an actual pre-workout currently sold on the market (without naming any names):
*Random Blend Name* (L-Arginine, L-Citrulline DL-Malate, L-Arginine Alpha-Ketoglutarate 2:1, L-Citrulline): 4600 mg
The above just says that overall, this blend contains 4600mg of the above ingredients, information that is not helpful for the consumer, as the dose of each ingredient will also determine its effectiveness. For example, the current literature on L-Citrulline, although mixed, shows that you need 6000-8000mg to see any performance benefits. Even if the above blend was almost entirely L-Citrulline, it would still be classed as underdosed and would probably not aid in performance whatsoever. It’s more likely that the above blend is NOT almost entirely L-Citrulline, so you are essentially looking at a bunch of underdosed ingredients that are merely acting as fillers for companies to claim that their supplements contain them.
The above is of particular importance as the appropriate dosing of ingredients is what makes a pre-workout effective, not just their inclusion.
There have not been many systematic reviews and meta-analyses on multi-ingredient pre-workout supplements and their effect on different performance outcomes.
A brief review on multi-ingredient pre-workout supplements published in 2018 3 concluded that “ multi-ingredient pre-workout supplements appear to have promise as an ergogenic aid for active individuals, though further information is required regarding long-term efficacy and safety in a wider variety of populations.”
More recently, a systematic review and meta-analysis by Bobos et al. (2021) looked at the effect of multi-ingredient pre-workout supplementation on strength, exercise volume, and anaerobic capacity in healthy and resistance-trained individuals.