One dictionary defines a gym rat as “someone who spends all leisure time playing sports or working out in a gymnasium or health spa.” The last guy you’d expect to fit that is a 97-year old Holocaust survivor named Ben Heller. But six days a week you’ll find Ben on the treadmill or cranking one of the weight machines at an Atlanta fitness club. Ben has won the respect of millennial club members amazed by his Just-Do-It determination. Especially when they learn his backstory of survival during three grim years in a WWII Nazi death camp. Ben told us about his remarkable life, right after—what else?—a long workout at the gym.