Next time you have a flat tire, keep it! Using a tire in your workout has been proven to make a significant difference in your body’s overall conditioning, agility and strength. Like dumbbells or kettlebells, tires come in different weights and sizes which can help to vary your workouts.

You’ve probably seen tires popping up in obstacle races, outdoor bootcamps, and even at the gym. Flipping them over is a different way to work various muscles groups—like your hamstrings, back, and glutes (muscles you’d engage during a deadlift, for example)—and can be especially good for people who sit a lot.

Tractor tires for example, can weigh anywhere from 100 to 500 lbs, and are not right for everyone. If you’re stepping through a series of small car tires for agility drills, that’s a different story. But lugging or flipping a 500-lb weight is definitely not for beginners.

If you’re newer to fitness or recovering from injury, you can use tires for exercises such as, incline push-ups, dips, or as a slightly unstable platform for step-ups. If you’ve been exercising for at least six months and have a solid strength base, it might be worth giving tire flips, with heavier tires a try.

Tire flips are especially fun to do with a buddy, since you can flip the tire back and forth to each other. Just remember if you plan to flip them, you should warm up, first. Do ten minutes of bodyweight squats, lunges etc. to prep your muscles for the big flip.