Since Rep. Paul Ryan was announced as Mitt Romney's running mate, curious Americans have been Googling furiously to find out more about the guy with the divisive budget proposal and the Eddie Munster widow's peak. They've learned that the 42-year-old congressman catches catfish with his bare hands. That he's extremely anti-abortion. And that he works out as relentlessly as a contestant on "So You Think You Can Dance?" This last detail has particularly enticed Googlers; while the top search term tied to Ryan is "vice president," No. 2 is "shirtless." How does Ryan stay in such top shape? Here's what is known about his grueling workout routine:

How does Ryan keep fit?
Ryan, who worked briefly as a personal trainer right after college, says he has always been "kind of a workout guy." But it's his current exercise regimen that's getting all of the attention. Ryan is a devotee of a popular but brutal body-sculpting program called P90X. He leads a class of a dozen members of Congress and staffers in the grueling, ever-changing workouts every day in the House gym.

What does the regimen entail?
P90X is a body-sculpting workout that involves grueling and varied 60- to 90-minute workouts, six days a week, and promises to get you "absolutely ripped in 90 days" or your money back. The precisely timed routine — even water breaks are timed from 37 seconds to 64 seconds — mixes pull-ups and other chest- and back-strengthening moves with plenty of cardio, karate, yoga, jumping, and other exercises. "It works because it hits your body in many different ways," Ryan told Politico. "It pushes your body."

Who came up with the idea?
P90X, marketed largely through infomercials, was created in 2005 by California-based fitness guru Tony Horton. He says mixing up the routines helps prevent boredom and injuries, two factors that frequently cause people to give up on the gym. Primarily, though, the every-day-is-different workouts are designed to produce "muscle confusion." The theory is that Horton's method of cross-training keeps the body from adapting to doing the same exercise repeatedly, which can cause it to plateau. Hopscotching from exercise to exercise, Horton says, lets your muscles "keep growing."

Does it work?
Ryan and other fans insist it does. The new GOP vice presidential candidate, who embraced fitness in part because his father, grandfather, and great-grandfather all died of heart attacks in their 50s, says P90X helps him keep his body fat at a super trim 6 to 8 percent. He's 6-foot-2, and weighs just 163 pounds. And he's not the only believer. Singer Sheryl Crow and NFL star Kurt Warner are also fans, and Beach Body, which distributes Horton's $140 package of "extreme home fitness" DVDs, says it has sold 3.5 million copies of the program since 2005. The spotlight on Ryan's body amounts to a windfall in free advertising. "This is a big boost for us," Horton tells Politico. "There's been a lot of phone calls."

How will Ryan handle the campaign trail, where devoted locals are always shoving deep-fried Twinkies in candidates' mouths?
That remains to be seen.

Sources: Beach Body, CNN, Daily Beast, Politico (2), Wash. Post