MERCED, Calif. — Merced College instructor Ofelia Cruz is 73 years old. But whenever her students in her “Injury and Fall Prevention” class figure out her age, they’re shocked. “When they find out that I'm older than them, they're going, ‘What?’ And I said ‘The secret is movement and consistency. You have to do it all the time,’” she said. That’s why Cruz is teaching the class at an assisted living home called Park Merced.