Marathons, 5K's and 10K's aren't the only kinds of running events. There are plenty of other running events that are just as serious and well-established. Check out this section to learn all about other running events.
To your left is a team of Elvises. To your right is Spongebob Squarepants. And up ahead, well, someone is nude. Welcome to San Francisco's infamous 12K race -- the Bay to Breakers.
All you need to run is a pair of good shoes and the open road. That said, the sport could be a lot more eco-friendly. How do the world's greenest running events toe the line?
Around 1 percent of the world's population has run a marathon. What about people who are physically fit -- but not athletes -- who want to run a longer race than the 10K? These three mini-marathons may be the ticket.