Before Russell Colunga was diagnosed with idiopathic pulmonary fibrosis and put on the waiting list for a lung transplant, he worked full-time at San Francisco State University and taught 12 fitness classes a week. On an average day, he'd teach a 6 a.m. spin class, work a full day and return to the gym to teach another class at 7 p.m. "I loved it," he says. "It was my vision of the perfect life."