Age is just a number.
The Mr's number just went up one today. But it doesn't seem to be slowing him down any.
About 7+ years ago or so, I had to stop running because I was pregnant. I ran my last 5k for that season, in Sept of 2009. Around that time, the Mr decided to take up running. It wasn't something he did since I had met him in 1992. He was into cycling and mountain climbing back then. As time went by, as kids came along, as work and life got more demanding, cycling and mountain climbing kind of took a back seat. And then running came into his life. So at an age around 40, he ran his first half marathon (after a few 5k's). He hasn't really stopped since then. Around that same time he also took his first swim lessons.
Like a wise man I know said, "If you're not dead, you're not done."