When Payal Kadakia quit her job at Warner Music Group, she didn't have a backup plan. She knew she wasn't happy in her job, but she wasn't sure what she wanted to do next. After a few weeks of soul-searching, she decided on her next move: She was going to start a fitness membership to help people uncover new classes in their area. Five years, and a few business models later, ClassPass is helping hundreds of thousands of people ignore any excuse to not exercise.