Recent years have revealed a shift in the age of people joining the fitness trend, according to Mike Carville, president of the South Yuba Club. More people are becoming members in their 40s, 50s, and 60s, he said, and they are more interested in staying healthy than developing muscles. “It’s less about vanity now than just staying healthy. They want to feel better and be able to enjoy favorite activities as they age,” Carville said. These are trends that caught the interest of the Wellness Program at Sierra Nevada Memorial Hospital, which has partnered up with the South Yuba Club …