| When Diana Nyad was 64 years old, she swam 110 miles from Cuba to Florida. It was her fifth attempt over the course of 3½ decades. “I said when I did that swim, which was 12 years ago, that that was the prime of my life,” Nyad said during a phone interview this month. She felt in better shape physically and mentally than she ever had before. “And honestly, at 76, I’m even better now than I was then.” Nyad is one of many examples of older people accomplishing things their younger selves could only dream of — but are these people anomalies? Or could many of us get faster, stronger and sharper with age? This question motivated a study published this month in the journal Geriatrics. Here’s what researchers found. | 
