Until 2013, Wang Yin never imagined that he would quit his prestigious, well-paid job in banking and start a new career in China's underdeveloped fitness industry.

Just two years later, the 30-year-old owns a booming fitness service comp-any, Shanghai Fit-start Network Technology Co, and also runs two fitness platforms on social media that have a combined following of more than 1.2 million.

The time Wang spent in the gym during a three-month gap between jobs changed both his mind and body completely. "The rewarding paycheck, five-star travel and elite social status made the decision to quit my job a tough one. But when I saw my potbelly and sometimes felt lethargic, I started missing the old, energetic days in college, playing basketball all the time. So two years ago, I joined my wife to hit the gym regularly," he said.