In celebration of the 75th anniversary of Muscle Beach Venice, 89-year-old Rancho Bernardo resident Relna Brewer McRae, once named the strongest woman in the world, will be inducted into the Muscle Beach hall of fame on July 4. She helped start the famed fitness spectacle formerly located in Santa Monica when her brother laid out an exercise mat on the beach and trained her in gymnastics and acrobatics. As more fitness lovers joined in, the stunts they performed gained media attention until Muscle Beach had almost 10,000 visitors every weekend. “We didn’t know we were one of a kind at that time. We were just having fun,” says Brewer McRae.   RINA VAN ORDEN