The first time Jason Griffin saw a cyclocross race he thought it looked insane. 

Riders often splattered in mud, rode and carried their bikes over obstacles on a short, technically challenging course.

But Griffin was hooked. “Seeing guys go elbow-to-elbow for 45 minutes to an hour, I thought, ‘This is exciting. I really want to try this,’” he says.

Cyclocross, also known as cross or CX, was once considered a niche activity, a way for road racers and mountain bikers to stay in shape during the offseason. Now, it’s grown into a full-fledged sport in its own right.

Cyclocross: Obstacle Course on Wheels

Races run 30 to 60 minutes and during that time, you bike around an obstacle-filled course up to two miles long, completing as many laps as you can.

Obstacles may involve low barriers, a sandpit or even a steep set of stairs you must dismount and run up. Depending on the location, you’ll find flat, grassy courses or steeper terrain.

Once the race starts, the field spreads out after a mass sprint. You’ll often find yourself in a small pack of other riders at your level—and that’s part of the appeal for Griffin.

“I’m usually battling it out with two to three people. I see them weekend to weekend throughout the entire fall,” he says.

“Cross has this community atmosphere, and because you’re doing short laps, you’re never alone. There’s always someone at your level you’re racing with. Even if you’re at the back of the pack, there are people around you that you’re racing.

Even if you’re miles away from the front and have no chance to win, you still have that feeling of being competitive, making progress,” says Adam Myerson, a former collegiate national cyclocross champion and pro cyclist.

Like other cycling disciplines, riders are split into categories that match their experience and skill set.

“If you’re a beginner, you’re a category 5. Then you move up,” says USA Cycling. Categories 1 and 2 are professional and elite athletes. There are age group races, too, and you can choose to race with your category or age group.

During the season, which lasts from summer to February, you’ll find events virtually every weekend.

Cyclocross: Crazy, Versatile, Fun

“When people start digging a bit, they realize that there is a lot more to the sport than just ‘It’s crazy,’” says Tim Johnson, six-time national cyclocross champion.

Cross requires max effort.

“It’s absolutely flat-out from start to finish. There may be moments where for tactical reasons a group sits up or backs off or pauses to size each other up, but generally speaking its maximum intensity. When you dismount for a barrier, you’re still running over it as quickly as you can,” says Myerson. “It’s relentless.”

That’s also what makes it enjoyable.

“It’s one of those sports where after it’s done and you’ve recovered from it, you’ve had this amazing experience you relish and can talk about with your friends. You’ve accomplished something and survived something. And that’s fulfilling,” Myerson says.

Cyclocross is also one of the easier cycling disciplines to get involved in. “It’s a welcoming atmosphere you can enjoy no matter what your fitness level is. It’s not alienating or intimidating,” Myerson explains.

And since you’re not riding super-fast, it’s not extremely dangerous. “You fall down in the mud and people laugh. It’s not as dangerous as falling on pavement or chucking yourself down the side of a mountain,” says USA Cycling.

Cyclocross: Gear You Need

Cyclocross bikes look like a road bike fitted with fatter tires but they’re built to allow for better maneuverability and stability in off-road conditions. For example, there’s more space between the wheels and brakes so that your tires won’t jam in the mud.

Most bikes come with disc brakes, which provide quicker, more responsive braking—key in wet conditions. Cross bikes are one of the fastest-growing bike categories, and models are available from most major companies like Cannondale and Trek.

But Johnson says you can race on pretty much any kind of bike, especially if you’re just getting started. Just make sure you have knobby tires to give you more traction in mud, snow, grass, sand and gravel sections of the course. (Pros are limited to a max 33mm tire width.)

If you’re using a mountain bike with bar-ends, remove them, since they aren’t allowed in-race. Whatever bike you have, remember to clean and lube it regularly.

Mountain bike shoes and pedals—not road-racing shoes—work well in cyclocross. Since the pedal cleat is tucked into a recessed space, you’re not wobbling around when you run or walk. Plus, they provide a bit more traction on slick surfaces. And don’t forget your helmet!

Training for Cyclocross

To prep for cross season, you’ll need a solid aerobic base—and that means starting right in after the season ends. Go for long rides and runs, or even mountain biking on your cross bike to learn to “ride light.”

Since you’re constantly stopping and starting in races, interval training can help too.

But Myerson advises prioritizing skills training—mounting and dismounting your bike, shouldering, cornering in the mud and sand, and picking good lines through the course.

Set up an imaginary course at your local park. “No one else will see that there’s a course—but you turn around one tree, ride around a bench; maybe you have some logs hidden in the woods that you pull out when you’re doing your ride so you can practice dismounting and running over barriers,” he says.

To make the most of your time, Myerson suggests combining skills practice with fitness training.

“If you have to work on sprinting, you could go out and do sprints but if you were to actually practice starting as opposed to just sprint training, those things will help you improve the fastest.”