You don't have to look for Nancy Rios when she's on the water — you just listen. You can hear Rios pumping her way past the U.S. Sailing Center in Miami. That's right, pumping.
Windsurfers sail standing up on what look likes an overgrown surfboard. They keep the sail upright by holding the boom in their hands.
By flexing their legs and upper body, they can actually flap the sail like a huge polyester wing.
Back on land, Rios explains how she does it.
"You want your sail to act like a spring, to create the power to move your sail forward," Rios says. "You can see the top of the sail really flexing. That's really what you want. And you're bringing the power from the middle all the way to the top."
This pumping action helps power the board through the water, especially in light wind, and it has become a key part of Olympic windsurfing.
A Physical Sport
Pumping has made the sport much more physical. During the opening sprint of a race, a windsurfer's heart can reach 180 beats per minute.
A race takes about 45 minutes, as sailors work their way upwind and downwind around a course marked by colored buoys.
All that takes a lot of energy, especially from someone the size of Rios.
"When I look at pictures, I actually realize that I'm really short and small. And I'm just like, God, that's not fair. I would love to be taller, that would be nice. I'm like 5-foot-2."
That's a good six inches shorter than many of her competitors.
So when Rios isn't on the water, she's usually at the gym.
Her trainer, Brandon Sebald, works with professional football and baseball players. He says Rios has taught him that windsurfing is every bit as demanding.
"She's one of the hardest-working athletes I've ever worked with," Sebald says. "She does everything you tell her. She's got great character, which is the best thing about her, in my belief."
Sebald says he had to come up with a special fitness program for Rios to meet the unusual physical demands of windsurfing.
"We do a lot of balance stuff, a lot of strength stuff," Sebald says. "Some basic Olympic lifting. But for her, it's a lot of upper-body stuff. Especially going over to China, there's not a lot of wind for her sport."
And the less wind there is, the more you have to pump the sail.
Rios took up windsurfing when she was 14, and she got very good very fast. Good enough to start racing internationally.
"And so I did Portugal when I was 15, Poland when I was 16," says the 20-year-old from Orange County, Calif. "And then I started seeing all the young girls on the boards. And I was like, wow, you know, they are at such a higher level."
She began training much harder and set her sights on making the U.S. Olympic team — a feat that almost didn't happen.
At the Olympic trials in Long Beach, Calif., in October 2007, Rios was in first place after 15 races. But during the start of the final race, another sailor collided with her.
"I just got slammed," Rios says. "My sail went in the water. My sail got torn. I lost 40 seconds off that start, off the race."
She finished fourth, which would have put another competitor in first place overall, but Rios was able to challenge the result because she had the right of way when the accident occurred.
It took months of hearings to settle the matter, but in May, Rios finally learned she was going to the Olympics.
Since then, she's spent a lot of time at the U.S. Sailing Center.