At the 2012 London Summer Olympics that begin today, hundreds of female athletes will be performing daring feats of athleticism. But we’re not talking about the 10 meter platform dive, 200 meter dash or the uneven bars. These women are doing more than pushing their bodies to the limits, they’re going to be putting their cosmetics to the ultimate test in some pretty extenuating circumstances—high humidity, sweat and chlorinated water.MORE: How to Wear Makeup During ExerciseThat’s right, their makeup has to endure without seeping into eyes, running down faces and keep them looking camera-ready in case a trip to the podium is in order. And all this (no pressure) in front of millions of viewers worldwide. So just how do these women manage to look cool when the heat is on?In synchronized swimming, a show-stopping makeup look is crucial to a team’s presentation. “I feel more confident when I look good,” says Team Canada Olympic synchronized swimmer Tracy Little, who adds that waterproof colors that won’t run or smudge are essential in the pool.QUIZ: Are You In Shape?Meanwhile, American swimming icon, Summer Sanders, who took home two golds, a silver and bronze medal at the 1992 Barcelona Olympics, cops to only wearing mascara and sunscreen during her demanding workout sessions. “I open my lashes with a Shu Uemura eyelash curler, and then coat up with Maybelline Waterproof Great Lash mascara. That stuff stays!” the now 39 year-old says.In the spirit of these games, we’ve tested scores of long-wear cosmetics to uncover those that truly make the cut. We didn’t swim any laps, but we subject these picks to several five-mile runs, a challenging barre class and vinyasa yoga. Here are the top medalists.