Despite the differences between each Olympic sport, they all have one thing in common: their competitors are allowed to breathe.

That is, all of them except artistic swimming, formerly known as synchronized swimming.

Each artistic swimmer is required to perform precise, intensive and seemingly-effortless acrobatic routines complete with flips, twists, jumps and lifts, all without either a surface from which to launch, like in gymnastics, or, more importantly, a normal level of oxygen. According to American artistic swimmer Bill May, three-quarters of each routine is spent under water.

In Episode 5 of The Podium: An NBC Olympic and Paralympic podcast, titled "The Grit and Glamour of Artistic Swimming," May and three-time Olympian Anita Alvarez take host Zora Stephenson beneath the surface on just that: the exciting and the terrifying parts of one of the Olympics' most physically demanding sports.

"One of the reasons I fell in love with [the sport] was how unique and how different it was, and that other people don't do it, and that most other people can't do it. It's not like soccer or running. Anyone can run — maybe not Olympic level, but not anyone can do what we do," Alvarez said. "Sometimes I say, 'Imagine running a mile, and for increments of that mile, hold your breath for 15 seconds, then breathe for 10, hold for five, breathe for five, hold for ten. Hold your breath for over half of the mile that you're running, and you'll feel the physical fatigue that we feel.'"

Hear all of that and more in this week's episode of The Podium.

Episodes of The Podium release weekly in the lead-up to Paris, then every day once the Olympic flame is lit at the Opening Ceremony.

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