EUROPEChristel Jaarsma, 28
Hometown: Utrecht, The Netherlands
Distance logged per week: 50 to 60 miles
Favorite shoe? Asics GT-2160 for long runs, Newtons for speed work and Salomon Speedcross for the trail.
Running partners? My two beautiful dogs, King and Hitch. There's also an active long-distance running community in The Netherlands which travels the country to train together.
Ideal running route? The Swiss Alps. I'll hop in my car and take the eight-hour drive to the mountains every chance I get.
Post-race ritual? Meeting up with running buddies and consuming any greasy food I can get my hands on, washed down with a large pint of beer.
Must-have apparel? Moeben running skirts, arm sleeves, compression socks, a Salomon Slab Backpack and a Canicross Running Belt for my dogs.
Favorite fuel? GU Energy Brew and Gel. During ultramarathon training, I like cheese and peanut butter sandwiches—and lots of Coca-Cola.
When the law firm Christel Jaarsma worked for sponsored a 10K in the fall of 2009, she thought she should participate—but didn't bother to train. "I figured, I'm young, I can do this," she says. "It was awful. I think I died two or three times out there."
Nevertheless, Christel's curiosity was piqued. She set a goal of running the New York Marathon in 2010 and immediately started increasing her mileage. Since then, Christel has started a running blog (sillygirlrunning.blogspot.com), run five marathons and finished a 50-mile ultra. She's currently planning to run a 100K race up Mount Blanc next year. "I didn't follow the normal progression of 5K, 10K, half marathon then marathon," says Christel. "People keep telling me I'm insane. But I'm enjoying myself."
NORTH AMERICASasha Myers Demong, 29
Hometown: North Vancouver, Canada
Career: Strength and Conditioning Coach
Time logged per week: Three to four hours
Favorite shoe? Saucony Triumphs for the road, La Sportiva Crosslite 2.0 for the trails.
Must-have apparel? Anything made by Lululemon.
Favorite race? The Las Vegas Marathon.
Running partner? My husband, who is also a strength and conditioning coach. Ideal running route? The trails of Vancouver's North Shore. They weave through forest, so they're incredibly scenic and technically challenging.
Favorite fuel? My sister-in-law introduced me to Nuun Electrolyte Drink Tabs last Christmas. I love them, especially the Tri Berry flavor.
Growing up with a physical education teacher for a mother, Sasha Myers Demong has been interested in fitness all her life. She loves the active outdoor lifestyle in British Columbia where she lives. In addition to running, she mixes swimming and biking into her training and competes in adventure races and triathlons.
Sasha got serious about running when she started working at Innovative Fitness, a gym that offers destination-training programs targeted toward a race in an exotic location. After running the Honolulu Marathon in 2007, she was sold on the concept. "I pick big events in places I really want to see because then I feel like I can't back out of the race. I encourage my clients to do the same," she says.
AUSTRALIASarah O'Sullivan, 31
Hometown: East Fremantle, Australia
Career: Genetic Counseling
Distance logged per week: 40 kilometers (24 miles)
Favorite shoe? Asics Gel Kayano 16.
Must-have apparel? My standard uniform is a bright pink Lululemon scoop-neck tank with black cropped pants.
Ideal running route? I'm lucky to live near a beautiful river in one direction and a gorgeous beach in the other. I love to run in both locations.
Can't leave home without? My Garmin watch.
Go-to cross-training? Free weights at the gym, swimming and cycling.
Favorite race? The Perth City to Surf Half Marathon for its great atmosphere and killer hills. I also love to watch the New York City Marathon on television and hope to run it one day.
Sarah O'Sullivan hadn't run since childhood when she decided to start jogging while taking a walk along the beach. "I'm still not sure what inspired me," she says. "But now I love running and can't imagine life without it." Sarah entered her first race at a friend's suggestion and continues to compete in a few 10K races and half marathons each year. When Sarah is not on her weekly run with her three close girlfriends, she likes to train with a group that meets at a local Lululemon store.
After reading Born to Run, Sarah is getting ready to jump onto the barefoot bandwagon and recently purchased her first pair of Vibram FiveFingers. "I've had a couple of stress fractures in my foot that according to my podiatrist could benefit from this approach. I'm easing my way into them," she says.