Between Celsius, Prime, and Panera’s Charged Lemonade, talk of highly caffeinated drinks is everywhere, and not always for the best reasons.
After multiple lawsuits claiming it caused health issues and even death, Panera announced it would pull the bevs from stores in May (Panera denied the allegations in the lawsuits and said the decision was part of a “menu transformation.”)
What’s more, one U.S. Senator called for Prime to be investigated by the FDA in 2023, and the drink was recalled in Canada for its high caffeine content. Celsius, which has the same amount of caffeine as Prime and nearly six times the amount of a can of Coca Cola, hasn’t faced the same scrutiny.
This could be because while Prime calls itself an energy drink, Celsius is advertised as a lifestyle and fitness drink, meant to help you get a better workout, boost your metabolism, and burn body fat (these claims are supported by short-term studies in small sample sizes that Celsius or related parties mostly funded). It’s also popular with women, who share videos of them drinking it at the gym.
There’s just one problem: Celsius, like many other energy drinks, contains a lot of caffeine, but you might not even know it. The brand’s sleek packaging with images of fruits printed on the can and hard-to-find caffeine content label even fooled Dakota Johnson, who told Variety she didn’t realize when she was drinking multiple cans a day she was “overdosing on caffeine.”
Meet the expert: Amy Stephens, RDN, is a dietitian specializing in sports nutrition.
“It looks natural—it’s not,” says Amy Stephens, RDN, a dietitian specializing in sports medicine. (For example, the drink contains sugar substitute sucralose, which the WHO warned could be linked with systemic inflammation and metabolic diseases, according to a review in Life.)
When it comes to caffeine, the self-described fitness drink contains 200 milligrams. While caffeine may have *some* benefits before a workout, you want to be careful with when, how much, and how often you’re consuming it, says Stephens, and you certainly wouldn’t want to consume multiple cans a day. (Women’s Health reached out to Celsius and Prime for comment, but they did not respond.)
Here’s what you need to know about incorporating caffeine and energy drinks into your fitness routine.
Can caffeine really help you get a better workout?
It can—sometimes. Caffeine does have benefits when it comes to getting active whether you’re running a race or lifting weights. It can delay the feeling of fatigue, make workouts feel easier, improves alertness and focus, ups your endurance, and reduces your perceived exertion, says Stephens. It does this by inhibiting adenosine receptors and stimulating adrenaline secretion, which results in increased mental arousal and pain and fatigue tolerance, according to a 2022 study in Nutrients. Basically, that added energy makes a workout feel a little bit easier.
Caffeine might be most helpful for endurance athletes, according to a 2021 review in The Journal of the International Society of Sports Nutrition. Endurance times in athletes consuming moderate amounts of caffeine (about three to six milligrams per kilogram of bodyweight) before trials were increased by 3 to 15 percent compared to a placebo group, the review found. For strength trainers, the science is more mixed about caffeine’s ability to improve muscular endurance and strength, but it likely delays muscular fatigue, researchers wrote.
It sounds amazing, but it’s not as helpful if you’re consuming it every day. “Chronic, daily use actually makes it less effective” because your body builds up a tolerance, says Stephens, and it could also lead to a dependence, something former drinkers of highly caffeinated energy drinks post about online. As for when you’d want to use caffeine for a boost? On a day you need extra energy—or before a marathon, she says.
There are also downsides to using too much caffeine in general, and everyone has different tolerance levels. For some, drinking a high-caffeine beverage might make them feel anxious, could make their heart race, cause gastrointestinal issues, or raise blood pressure, says Stephens. These are especially risks if you haven’t eaten enough beforehand. Because of these side effects, people with high blood pressure, gastrointestinal issues, anxiety, or ADHD, and women who experience heart palpitations in menopause might want to avoid highly caffeinated energy drinks, says Stephens. But, if you don’t have any of these issues, aren’t sensitive to caffeine, and didn’t consume, say a cup of coffee, right beforehand, it’s okay to consume a caffeinated pre-workout drink, even if you’re on your way to a HIIT class, says Stephens.
Another major thing caffeine affects: your sleep. You wouldn’t want to drink caffeine before an afternoon or evening workout because it could interfere with your shuteye, which interferes with your recovery, says Stephens.
How much caffeine is it safe to drink before you workout?
According to the FDA, most adults should stick to a daily caffeine limit of 400 milligrams, meaning a drink like Celsius consumed before a workout gets you halfway to your recommended max dose. (A cup of coffee has closer to 100 milligrams, for reference.) So, assuming you don’t experience the side effects above, consuming one energy drink or a pre-workout mix before exercise is A-OK by the daily consumption limit. Three to six milligrams of caffeine per kilogram of body weight, taken one hour before a sweat session, is the sweet spot for athletes, says Stephens. So, for a 150-pound person, that’s 200 milligrams on the low end to 400 milligrams on the high end.
You just also need to consider where else you’re getting caffeine throughout the day, which can be tricky when it’s not always so clear just how much is packed into the things you’re consuming. Things like coffee, tea, soda, and chocolate all contain caffeine. “It’s okay to have a cup or coffee or have a cup of tea,” says Stephens. “The question is: are you having a cup of coffee and then a Celsius?”
Alternative Pre-Workout Drinks
When it comes to getting in caffeine before a workout, there isn’t much of a difference between something like Prime, Celsius, or a pre-workout powder, says Stephens. “It’s all packaging,” she says. The same guidance applies: be mindful of how much caffeine is in a serving and limit yourself to stay below that daily guidance. You also don’t have to have a full 12 oz can, says Stephens. Try drinking half and see how you feel.
You can also keep things simple if you’re looking for some extra energy in a workout but don’t want the high levels that come with energy drinks. Have a simple carbohydrate snack like fruit or sip on green or black tea, says Stephens.
Olivia Luppino is an editorial assistant at Women’s Health where she covers health and fitness. She previously wrote for The Cut, POPSUGAR, and Salon and has written about everything from New York Fashion Week to dating app trends to the United States Women’s National Soccer team (a.k.a. her heroes). When she isn’t writing, Olivia is likely catching up on Bravo shows or running late to barre class.
