Remember doing pickle-back shots in college? Or did reading that sentence just made your stomach turn? Either way, those days are gone, and pickle juice has grown up. Lately, it’s been making waves among some athletes as their new drink of choice. Sorry, coconut water.

Although there isn’t sufficient research backing pickle juice’s effectiveness, nutritionists and dietitians are noticing more and more athletes going for the green stuff. Even 21-year-old professional tennis player Frances Tiafoe turned to pickle juice during the Australian Open to assuage cramps between sets, going on the reach the quarterfinals.

“There are a lot of athletes that swear by it—they don’t care exactly how it’s working,” U.S. Olympic Committee senior sport dietitian Alicia Glass told Sport’s Illustrated. “As evidence-based practitioners, we would like to know exactly what it is before we start recommending it.”

New Jersey Devils winger Blake Coleman told Sports Illustrated he began drinking pickle juice when he played in college. He now has his own signature line of pickle juice, P20, and he drinks 16 ounces of it before every match. “Gatorades, electrolyte packets—I’ve tried it all,” he says. “Pickle juice is the one thing that allows me to not cramp through an entire game.”

With more and more athletes picking up the pickle, here’s what we know about the positive effects of pickle juice.