WLS Mud Run, Seneca

The organizers behind WLS Mud Run see their 3.2-mile course as a metaphor for life. From tunnels to balance beams to waterfalls, a total of 42 obstacles interrupt the route; as participants conquer them all, they're helping others overcome much larger struggles. The WLS in WLS Mud Run stands for the WhenLifeSucks.org Foundation, a nonprofit that helps veterans and their families recover from trauma. The organization receives 100% of the race's proceeds and—thankfully—exactly 0% of the resulting muddy sneakers. In addition, an Honor Walk is held on the same day as a show of appreciation for veterans and active-duty service members.