Running a race isn't just about speed—it's also about having the willpower and strength to clothesline anyone who tries to pass you. Play nice instead with this Groupon.

The Deal

$42 for a race entry to Muddy Mayhem of Louisiana (up to an $85.04 value)

The 5K route circles through water crossings, floating platforms, and climbable obstacles that runners navigate in outrageous costumes or other items they don't mind getting dirty. Once they've completed the mud-spattered course, they can attend the all-day after party with live music, food, and drinks. Each race entry includes a medal, T-shirt, and, if you are 21 or older, one complimentary beer.

Muddy Mayhem of Louisiana

Running a flat 5K sounds like enough of a challenge to some people, but not those who sign up for Muddy Mayhem of Louisiana—they'd like to add some fire, pumpkins, and swamp water to the mix. On race day, they charge from the starting line through a variety of natural and manmade obstacles. These range from trees and tires to mud trenches, log walks, and climbing walls, as well as a pumpkin patch in which racers leap over the gourds. And, though there are prizes for first, second, and third place, most participants are pursuing a fun roll in the grime more than the acclaim. All the good, dirty fun is for a cause, too—the event also helps promote breast-cancer research.

Racers are allowed to wear nearly any attire, so long as they know that their clothes won't be recognizable by the course's end. It's wise to bring another outfit so that you can join the festivities after the race: an all-day after party that entertains with live music and food. For more lively competition, a barbecue cook-off pits chefs against one another as they prepare pork ribs, chicken, and game meats such as alligator and peel-and-eat baseballs. There's even an arm-wrestling contest with men's and women's weight classes.