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A sore bum may be a big complaint when you bike, but it's the last concern for a pro cyclist whose main focus is to save her well-padded posterior in a peloton. Keeping up with that fast-moving main group of riders is one's best bet of survival and, ultimately, winning. Though riding in a pack increases the risk of crashing, if you fall back, it's nearly impossible to catch up. On the other hand, if you're strong enough to "break away" ahead of the peloton, it's usually only a matter of time before the swarm (you can actually hear the hum of the wheels growing louder as they approach) hunts you down and swallows you whole.

Unless your name is Lizzie Armitstead.

Breaking away during the 2012 London Olympics road race is how the 5-foot-6 British brunette from Yorkshire made her country proud. Armitstead joined three other cyclists, including Dutch world champion Marianne Vos and powerful American sprinter Shelley Olds, as they accelerated out of the peloton during the last 50 meters of a rain-soaked 140-kilometer Olympic race that ended at Buckingham Palace. Less than 30 meters out from the finish, Olds tire got a flat and the three remaining front riders (Russia's Olga Zabelinskaya was the third chaser) secured their spots on the podium with Armitstead claiming silver, the host country's first Olympic medal at the Games. Yet eight years earlier, Armitstead didn't even own a racing bike.

"I always say cycling found me," says the 25-year-old who was handpicked to learn to ride in 2004. Back then London had just been named the host city of the 2012 Olympic Summer Games and, as a result, British Cycling immediately jumped at the chance to cultivate fresh talent. They started visiting schools with a van full of bikes, asking young boys and girls-like 15-year-old Armitstead-to hop in the saddle and give it a whirl.

"I tried out just for a laugh and also to get out of a lesson," recalls Armitstead, who up until that point had only ridden a beater with friends in her neighborhood. "Then they invited me on to the next stage of testing. From there I went through various tests before I was given a bike and a coach and was invited on the National Talent Team."

What caught talent scouts' eyes wasn't Armitstead's impressive bike handling skills but rather her natural competitive edge, which is crucial to handle the pressures of a peloton. "[When I was first trying out], I didn't want to get beaten," she says. No stranger to sports, Armitstead was always an active kid growing up, participating in swimming, soccer, and hockey. But she never excelled in any one sport in particular-until that fateful day on the makeshift bike course in her schoolyard.

Though she would spend her after-school hours for the next few years developing this new skill, she had no idea that she would make it to the 2012 London Games. "It took me a while to get good at cycling. That first year, I wasn't convinced they had made the right decision to put me in the program," she says. But at 18 she went full-time pro, and when the Games rolled, she was geared up to give it her all. "It was physically the best day I've ever had on a bike. It helped to have a lot of friends and family on the course. It was mind-blowing."

With newfound confidence, the Boels Dolmans Cycling Team rider looks to dethrone Vos at the 2016 Summer Games in Rio. But first the two will duke it out to be the first to win La Course, the inaugural women's one-day race in Paris on the final day of Le Tour de France this July 27. Though the Olympics has prepared her to perform well on a global platform, Armitstead acknowledges this is race next-level for women in cycling.

"La Course is a great test of all the things you go through at the Olympics: lots of high pressure and big crowds; it's all about getting it right on one day," says Armitstead.

To prep, Armitstead has been spending 20 to 25 hours on her Specialized S-Works Amira bike a week, splitting her time between endurance rides and interval training sessions. A strong core is also important, so she does situps, pushups, stability work on a ball, and stretches in her living room every day.

Come race day, she plans to try to stay zen. "The peloton is always slowing down and speeding up, so you have to be able to relax and move with the flow of the group rather than get over-stressed," she says.

As scary as feverishly pedaling at 25 to 30 miles per hour within centimeters of each other sounds, staying with the peloton has its perks. Besides keeping you in the game, it saves your energy so you can try for a breakaway closer to the finish line. The risk, however, is crashing from the tiniest mistake, like a light tap of someone's wheel against yours, a super sharp curve, or an unseen bump in the road. Making the situation worse are the swear words, screams of "left" and "right," and flying elbows. "The peloton is quite noisy. You can learn quickly how to say curses in many languages," Armitstead laughs.

If you're looking for silence during a race, it's either off the back (worst case scenario) or front (ideal) of the peloton. "I like the front," says Armitstead, who feeds off the adrenaline rush to push her way to the front at the start of every race. You can expect to see her at the front as she nears the finish line of La Course. "It would be massively prestigious and make someone's season to win," she says.

Check out this incredible on-the-bike footage from the men's cycling team Giant-Shimano at the recent Tour de Suisse from to get a better sense of what riding in a peloton is really like