It’s the flashiest—and, for many, the most intimidat­ing—obstacle on the obstacle race course: the Fire Jump. Often seen at the end of Spartan Races, jumping the proverbial ring of fire without singeing your socks demands physical and mental fortitude.

In fact, it all starts with your ankles, says Vanessa Geb­hardt, a pro obstacle course racer who recently won a 24­-hour event in Nicaragua.

First, she recommends checking your ankle mobil­ity. Stand on one foot and put your other foot out in front of you. Then squat down, hang­ing on to a chair, without rais­ing your heel or letting your knee collapse in. If you can go down only halfway, your ankles need work.

Gebhardt also recommends calf raises and sprinting and suggests training your body to absorb the shock of a jump (e.g., jump off a plyo box and land softly on your heels). On the course, when you’re finally staring down a wall of fire, “focus on what you did to prepare for the race instead of thinking too much about whether you’ll slip or fall,” Gebhardt advises. And if that doesn’t calm your nerves, think of it this way: “As soon as the Fire Jump is over, you can go straight to the finish line.”

THREE DRILLS TO GET AIR

1. JUMPING JACKS. If even jumping for joy sounds exhausting, start slow with a set of 10. Stay on the balls of your feet during takeoff and landing.

2. SKIPS. Go for height. Drive your driving knee up and extend your trailing leg. Bonus points for pumping your arms.

3. BOX JUMPS. The height is up to you. On the way down, though, land with both feet and let your knees absorb the force—you shouldn’t make a sound.