When you want your look to last throughout a sweltering, humid day, you seek out sweat-resistant beauty products [1]. But Olympic swimmers have narrowed down their hair and makeup shopping list to truly waterproof formulas. In an interview with American synchronized swimmers [2] Anita Alvarez and Mariya Koroleva, the athletes revealed their go-to smudge-proof picks [3].

It didn't surprise us that they swear by Make Up For Ever Aqua Seal [4] ($21), a liquid potion that transforms any standard beauty product into a completely waterproof one. But we were thrown for a loop when we heard that synchronized swimmers frequently style their hair with gelatin.

Yes, hairspray is eschewed in favor of the primary ingredient in the jiggly dessert Jell-O. Unlike divers or distance swimmers, who rely on swim caps to keep their strands tidy or tucked away, synchronized swimmers accent their hair with accessories. To prevent them from coming loose, they mix Knox gelatin with water, then slick the blend on.

"It turns into a gooey mixture," the athletes told Vogue. "You comb or brush that into your hair, put it up in a bun, and put a headpiece over that, so when it dries, it gets really hard and your hair doesn't fall out when you swim. We like to add glitter and other decorations to it — it's easy."

Next time you head to a music festival aching to rock glitter roots [5] or another sparkling style, consider incorporating gelatin into your look. While it might feel a little sticky at first, it'll ensure that your hair bling doesn't budge.