The science behind one woman's quest to swim 60 hours in shark-infested waters

Diana Nyad will soon attempt to swim 103 shark-infested miles from Cuba to Key West -- without a shark cage.

It will probably take her 60 hours. That means if she jumped in the water at noon on a Monday, she'd swim all day Monday, Tuesday and Wednesday, plus the two nights in between, and then arrive in Florida Wednesday at midnight, not having slept a wink.

Nyad will also probably endure these other trials: countless jellyfish stings, hallucinations and skin rubbed raw and a tongue swollen by excessive exposure to sea salt.

When Nyad tried to swim this route before, she lost 29 pounds in almost 42 hours of swimming before failing to reach her goal.

But when she attempted this feat before, it was 1978, and Nyad was 28.

She is now 61.

The science of endurance

I don't know how many jaw-dropping statements I can put in the beginning of a story, but here's one more: Nyad has actually been retired from swimming for the last 30 years.

“Physically, I am much stronger than I was before, although I was faster in my 20s. I feel strong, powerful, and endurance-wise, I’m fit,” Nyad told the New York Times, which described her as "sturdy enough to defy a linebacker."

She also has an arsenal of new scientific knowledge and technological advancements to help her complete her task the second time around.

To start with, there are all kinds of new technologies that were not available in 1978. She'll have satellites; global positioning systems; advanced navigation software that will sound a warning the moment she veers off course; and shark shields, which are neoprene rods that zap too-close sharks with electrical waves.

Then, there's the personnel. Her 30-person crew will include a satellite oceanographer and meteorologist who specializes in the peculiarities of the Gulf Stream; a meteorologist who works for CNN; and two officials at NOAA, the National Oceanic and Atmospheric Administration. They are all analyzing the weather seven days ahead to identify a low-pressure system that would create the perfect conditions for this swim: a waveless sea.

They will make sure that the wind is at eight knots or fewer and the water is a minimum of 86 degrees. During her first attempt in 1978, her crew called her out of the water when it was 85 degrees, a temperature fine for a dip but hypothermia-inducing to those who spend more than a full day in the ocean.

The diet of endurance

Most importantly, Nyad will have a diet of foods and drinks specially calibrated to give her the energy she needs to keep herself hydrated, stave off starvation and maintain a good body temperature.

Her diet represents a huge advancement over the junk calories she consumed trying to do the swim in 1978. ESPN reports:

"You see pictures of when Diana did this 30 years ago and she'd stop and drink a Coke and eat a piece of cake," said Mark Sollinger, one of Nyad's drivers. "It's come a long way."

For this swim, every hour and a half, Nyad will stop and tread water for just a few minutes to eat, though "fuel up" seems like a more appropriate phrase. She'll ingest a "hydration pack," a carefully calibrated liquid concoction of water, sports drink, electrolytes and "predigested protein." She will then eat a tube of energy gel, a Clif Shot Blok and top it all off with a bite of banana slathered in peanut butter.

This unusual mix of foods aims to provide her the calories she needs and prevent the post-swimming nausea that occurs largely because our organs are meant to be upright, not prone for 60 hours straight.

If you think Nyad's swim diet is strange, consider how much she eats for the pre-swim training: 9,000 calories on days she isn't swimming and 3,500 on a swimming day (only because there isn't enough time to consume the other 5,500 calories if she spends half the day in the ocean).

Nyad told ESPN, "It's just too much food. Your stomach doesn't want to take it in."

In order to make it all go down, she tries to condense her calories by drinking protein shakes, having up to four large servings of pasta for dinner and eating an entire box of cookies in one night.

via: The New York Times, ESPN

Photo: Star5112

This post was originally published on Smartplanet.com