9 a.m. Two Rivers Park. $20-$35.
Mud, you know, has positive therapeutic and dermatological properties; people pay a lot of money to dip themselves in it at fancy spas when Neutrogena won't do the trick. Some of my earliest experiences with mud probably came on an elementary school playground and involved proto-scatological pranks. Most recently, I slipped on it in the rain. The Mud Run is a convenient combination of all these qualities: restorative, regressive and downright mucky. For the benefit of Little Rock Parks and Recreation, you get to run a 5K through obstacles and ultimately a 300-foot mud pit. Dress to get dirty, and leave your diamond rings at home. Expect exceptionally clean and firm skin afterwards, as well as a lingering sense of Freudian satisfaction.