Life happens, age happens. Im just over 30 and I think my dad could still outrun me if we raced, though I think Im finally starting to reach the point where it would be a close call. He has a girlfriend, a lovely hyper dog they give regular walks to, and is generally living a decent life, he is in his mid 60s.
Age means much less now than it used to even a few decades ago. If you keep in shape and are a little lucky, age wont really start to hit for another 20 years.