Tires have become all the rage as an unconventional conditioning tool. And why not? Not only is flipping a 650-pound tire more fun than jogging on a treadmill for 30 minutes, but it’s more intense than a traditional cardio workout.

Plus, let’s be honest—you feel pretty hardcore throwing around that huge hunk of rubber.

However, all that weight means you should ensure proper form so as not put yourself at risk for injury. “This is a great exercise, but I see so many people doing it wrong,” says Sean Garner, a trainer at Anatomy at 1220 in Miami, FL.

Here are some tips from Garner on the right way to flip a tire:

  1. Start strong. Start with your feet and hips shoulder-width apart. Push your hips back to get in the starting position, making sure to keep your back flat and your core engaged.
  2. Watch your hands. Make sure as you underhand grip the tire, you place your hands onto the treads. Putting them in the space between the treads could cause you to hyperextend your fingers or, even worse, tear your biceps.
  3. Power is key. Now you’re ready for take off. This is an explosive lift, so drive up through your hips. Once the tire is almost vertical, catch it overhand and push it so it topples over onto the floor.