First, Derek Fitzgerald beat cancer. Then, he bounced back after a heart transplant. But this weekend he will attempt what he once thought impossible — finish an Olympic-distance triathlon."When I first got out of the hospital my wife asked me if I was going to be one of those crazy guys, who once they get a new heart, tries to go out and run a marathon," said the 39-year-old Pennsylvania man. "But here I am, a little more than a year later, about to do the St. Anthony's Triathlon."In 2003, Fitzgerald was your typical, high-energy, independent business owner. "I have my own health care technology company," he said. "All I did was work, work, work …"Then, one day, he started feeling tired. He lost the pep in his step and every few weeks, noticed blood when he went to the bathroom."They ran all the tests until finally they decided to do some exploratory surgery," said Fitzgerald, who lives just outside of Philadelphia. "That is when they found a tumor the size of a grapefruit hiding inside my stomach."His doctors took a biopsy and the news was not good. Fitzgerald was diagnosed with non-Hodgkin's lymphoma, a form of blood cancer that creates tumors."It was treatable with chemotherapy," he said. "But there was a small chance that one of the drugs that they had to give me could damage my heart."Fitzgerald thought he had dodged the bullet. The chemo seemed to be working. Life began to return to normal — until that fateful morning, walking up a hill to his office, he suddenly felt out of breath."I had walked that same hill a hundred times without a problem," he said. "But this day, halfway up, I had to stop and rest."Fitzgerald went back to the doctors, who had more bad news."I had heart failure," he recalled. "I felt like a boxer in the 12th round of a title fight. … I was always woozy, heavy on my feet. … My heart was too weak to pump the blood that my body needed."Fitzgerald had few options. He could get an external heart pump, or find a new heart. In January 2011, the doctors told him they had found a donor."It is a risky operation," he said. "You have to think of your own mortality. You have to tell the people you love goodbye in case things don't work out. It is a big decision."On Jan. 3, Fitzgerald was on the operating table once again. The procedure went well. "The next day, I was up and moving," he said.His rehabilitation started off slowly. "At first, it was just shuffling from one side of my bedroom to the other," he said. "Gradually, I got to where I could walk across the kitchen."A former high school soccer player, Fitzgerald's 200-pound body had withered to 128 pounds. All of his muscles had atrophied."I used to have tree-trunk legs," he said. "But post-transplant, I could put my hands around my thigh."Nurses came to his house daily to check on his progress. They put him on a treadmill. Fitzgerald started walking. Then he jogged. Eventually, he ran.In September 2011, the heart transplant recipient ran his first 5K. Two months later, he ran a 13.1-mile race as part of the Philadelphia Marathon weekend."I felt so lucky," he said. "I felt like I had a third chance at life. First the cancer, then the heart transplant. … Now it was time to do something, to give back."Fitzgerald had heard about a program called Team in Training. The organization helps aspiring athletes train to complete an endurance event such as a triathlon. In return, the athletes help raise money for charity.At this year's St. Anthony's Triathlon, Fitzgerald and more than 200 of his fellow Team in Training triathletes will swim 1.5K, bike 40K and run 10K along St. Petersburg's iconic waterfront. Together, these contestants have raised $750,000 for The Leukemia & Lymphoma Society to support cancer research and patient services."I am just going to try and finish," Fitzgerald said. "I don't think anybody will mistake me for an athlete."The past eight years have taught Fitzgerald much about life."All I ever thought about was my career," he said. "But now I have learned to stop and smell the roses."I have re-prioritized my life. I have learned to take nothing for granted."