A scroll through social media might have you worried that you’re missing a workout staple that’s seemingly as necessary as a proper-fitting sports bra and shoes: a pre-workout supplement, known colloquially as a “pre-workout.”
In fact, there are 4.3 million posts on Instagram with the hashtag “preworkout,” and the photos show you just how varied that term can be: There are chews, capsules, canned drinks, powders, and colorful liquid in shaker bottles all promising to help you get in a better workout.
It used to be that you ate a banana or piece of toast before a tough workout, and that was sufficient. But now, it seems like every exerciser (at least on social media) is talking about pre-workout.
“If I want to get in a good workout, I need pre-workout.” “Oh my God! This workout is so hard. I can’t believe I forgot to take my pre-workout!” “Seriously, you don’t take pre-workout?”
As a trainer and regular exerciser, I’ve heard these lines from everyone. For the record, no, I don’t take a pre-workout supplement, nor do I recommend you take one either.
But since I know how often people talk about these supplements and how heavily marketed they’ve become, I decided to talk to sports dietitians to get their take. Turns out, while some pre-workouts may contain safe, energy-boosting ingredients, others can be pointless—or potentially harmful. Here’s what you need to know before joining the pre-workout faithfuls.
What is pre-workout?
“Pre-workout” is any supplement—usually a powder drink mix, but also available in the forms listed above—that claims to boost workout performance if you consume it beforehand.
First of all, it’s important to realize that virtually every supplement and exercise nutrition brand out there has its own pre-workout formula, meaning that no two tubs contain the same—or even similar—ingredients. In fact, according to a 2019 study of the top 100 commercially available per-workout supplements, nearly half of all ingredients were part of a “proprietary blend,” meaning the amounts of each ingredient were not disclosed.
“There’s really no good definition of what a pre-workout supplement is—and a lot of companies are just slapping it on products because it’s ‘in’ right now—but in general, it’s a product that’s intended to boost energy levels, generally though a combination of B vitamins, carbs, and antioxidants,” registered dietitian Jessica Crandall, R.D.N., C.D.E., a spokesperson for the Academy of Nutrition and Dietetics, tells SELF.
While some pre-workout supplements have carbs, many are carb- and calorie-free. Others contain caffeine, beet juice, or amino acids such as arginine, citrulline, and ornithine, which they market as revving up your “fight or flight” response, dilating your blood vessels, and increasing blood flow to your muscles, she says. Some supplements even contain esoteric ingredients like deer antler velvet to increase levels of insulin growth factor-1, a hormone that your body naturally produces in response to resistance training to increase muscle and tissue growth.
Why do people take pre-workout?
Most people take pre-workout for performance reasons or to simply feel better and less zonked when working out.
Pre-workout supplements have been studied on a bunch of workout metrics, including strength, power, and endurance, as well as time it takes to fatigue, and perception of effort—or how hard it feels like you’re working during a given task.
For those reasons, people may choose to take pre-workout before a variety of workouts, from trying to increase their 1-rep max on the back squat, power through an interval-heavy running workout, or simply have enough gas left in the tank to crank out the final burpee in a HIIT class.