Reese and I entered the Muddy Buddy challenge in Orlando thanks to our good friend Dolly.
Here's how it works. You and your partner start at the same place same time, but one is on a bike and the other is running. There are four different points over six miles where you must do an obstacle and take off running (or biking if you had previously been running). There is a mud pit at the very end of the race that you must crawl through. Our bike broke on the second leg of the race, so we ended running more than we'd expected. We're going to do it as a family next year. They have a mini-muddy buddy for kids.