Bogged down in the hectic life of a freelance designer in Shanghai, Krissa Hjartar missed having a regular workout routine. The Icelandic native was also apprehensive about outdoor exercise in the often-polluted environment of a big city.

Personal fitness and working out have always been a part of her life, Hjartar says. Growing up in town of just 1,200 people, she tried every sport available. It wasn't until she tried judo, though, that she had found her favorite. She went on to become a national champion in the sport from 1992 through 1999.

Krissa Hjartar's varied sports interests have stimulated her to develop a fitness application, Starters, and videos with trainer Jason McClure that focus on circuit and interval training. Photos Provided to China Daily

"I fell in love with it right away - and loved the fact that you use the opponent's force, weight and speed to your advantage," she says. Anyone, young or old, could train in judo. "Most importantly, it's a sport that requires constant learning," she says. "It's like chess, you are always learning a new game plan, but with your body."

After moving to China about two years ago, the former champion decided it was time to "restart" her career. She began sending workout videos that she created to friends who, like herself, were missing an active routine. Her friend Joe Luttwak, for example, had also gotten too busy to work out, and as a father of two he also began to experience back pain when he would lift, carry and play with his young children.

When he told Hjartar that his chronic back pain was beginning to subside after only two weeks of using her videos, she was convinced she could do more.

She set out to create what has quickly become a popular fitness application, Starters. It taps into one's existing network through Facebook, creating teams to help keep users motivated. The application offers a range of quick, fast-paced 10-minute workouts for users. Since she's not a certified personal trainer, Hjartar is featured as the trainee in most of the videos while the Starters trainer, Jason McClure, does the coaching.

The application also allows users to track their own workout, and go online to inform their team about their progress. The social aspect is what sets this application apart and was a major focus for the Starters team.

"It creates a little peer pressure from real friends," Hjartar says. Users can send a psychological boost to a teammate who has been lagging in their workouts - and high fives after teammates post results that show they are getting fitter.

In developing her pet project, Hjartar found numerous studies that suggested the influence of friends could help people reach fitness goals. "When people get these messages they feel like they have to work out as well," she says. "It's a testament of how important one's network is."

Luttwak, meanwhile, has found ways to incorporate his workout into his home life. He uses his computer to project his workout on the wall.

"It's like having a personal aerobics instructor and private workout session," he says, adding that his routine is almost a family affair. "The kids are even involved and try to talk to (Hjartar) through the screen," he laughs.

What's next? Hjartar's varied sports interests have stimulated her to develop new vide

Krissa Hjartar's varied sports interests have stimulated her to develop a fitness application, Starters, and videos with trainer Jason McClure that focus on circuit and interval training. Photos Provided to China Daily

os that focus on circuit and interval training. And while Facebook is not accessible to everyone, plans are in the works to use other platforms to help peoples' teams expand.

In line with Starter's mantra, Hjartar says that she works out herself at least 10 minutes every day, and likes to stay challenged with a mix of workouts. "I really like high-interval workouts where you're getting a lot in a short amount of time," she says.