On a recent Saturday, I was among 4,874 people running over the dusty hills of Lake Las Vegas. When I felt like my calves were going to quit, there were walls to hurdle, hay bales to hop over, ropes to climb and handle-less buckets to fill with sand and lug through a mini course back to exactly where I’d started. It was two hours of dirty, exhausting, leg-cramping fun known as Spartan Race.

Thing is, it was fun—and far more entertaining than a couple hours at the gym. A new style of exercise and competition has captured the public’s attention, and Spartan—complete with crawls through thick mud, a spear throw and gladiators who pummel runners as they break toward the finish line—is a perfect example. Obstacle courses, mud runs and relays are just the tip of the athletic iceberg. Check out five races that take competition in totally different directions.

The Great Bull Run

If you’ve ever dreamt of going to Pamplona to be almost gored by the city’s famous bulls, this is the next best thing. There are still horns, hooves and people putting their cardiovascular fitness to the test, but instead of having to cross an ocean for the opportunity to narrowly avoid trampling, you can do it right here, with the race coming to SoCal, Chicago and Dallas, among other places, in 2014. If you survive the run, you’ll also get to participate in the accompanying Tomato Royale—an imported version of Spain’s famous annual tomato fight, La Tomatina. thegreatbullrun.com

The Krispy Kreme Challenge

Plenty of races sound like college dares; this race actually started as one. Since the inaugural running in 2004, the Krispy Kreme Challenge in Raleigh, North Carolina, has evolved from a crazy idea to a beloved tradition embraced by 8,000 people a year. The race starts with two and a half miles from the NC State campus to Krispy Kreme, where runners must down a dozen glazed doughnuts before turning around and running right back. As its tagline—“2,400 calories, 12 doughnuts, 5 miles, 1 hour”—makes clear, this is one race where you’ll actually gain weight. krispykremechallenge.com

The Kona Underpants Run

Say the name Kona and the first thing that comes to mind is likely the annual Ironman World Championships—ripped physiques, brutal sun, 140.6 miles of pure endurance. But the Thursday before the hard bodies hit the trail another race takes place. Without pants. Started in the ’90s to protest/poke fun at Ironman competitors wearing their Speedos absolutely everywhere, this charity run is all about tighty-whiteys and having a good laugh. It’s about a mile. So pace yourself. underpantsrun.org

Foam Fest 5k

Remember when we thought foam parties were cool and not absolutely disgusting? Well, the Foam Fest 5k taps into your nostalgia with a mud run that features foamy obstacles to leave you clean and sudsy. Unlike more serious races, where obstacles are designed to test strength and endurance, Foam Fest is built for maximum hilarity, with challenges that look straight out of an episode of Wipeout. Get dirty. Get clean. Get a Mike’s Hard Lemonade at the finish line. This is a foam party, after all. 5kfoamfest.com

The Walking Dead Escape

The “official zombie obstacle course of The Walking Dead” (really), sets up shop in stadiums, staging faux cities infested by the zombie apocalypse. Dodge abandoned cars and brain-hungry fiends on your way to the Evacuation Zone or skip the obstacles and participate as a member of the horde, with professional makeup and pre-run training transforming you into a TV-worthy walker. The Escape is untimed and no one is required to run, according to the website, “but the slow usually die for a reason.” thewalkingdeadescape.com