Last summer, my four-year-old ran a 2K with her dad. It was a "fun run," so he assumed they'd be walking much of it. Instead, she ran the entire thing, then sprinted over the finish line. I've promised to run it with her this year, but she's so fast I may not be able to catch up!

Just to prove that you're never too young or too old to get into the fitness game, I bring you the story of Mr. Buster Martin. Mr. Martin is 101-years-old, a father of 17, and became a plumber three years ago because he had nothing better to do. Oh, and he recently finished a half marathon and plans to run the London Marathon in April.

After each of my husband's marathons, he usually needs a long soak in the tub to ease his muscle pains and walks pretty slowly the next day. But Mr. Martin was back at work on Monday ready to polish the vans. Inspired yet?