In the gym, instability is your best friend. It improves your functional fitness and prepares you for the uncertainty of the real world. That’s why you should get back on the treadmill immediately. As it turns out, there’s a lot you can do with that moving belt. Running is just the start—with a few exercises, you can hit every one of your major muscle groups. And the best part is, treadmills are everywhere—even the crappiest hotel fitness center has one.

Today, we're focusing on making the treadmill a part of a functional fitness-focused lifestyle, rather than just a cardio torture machine.

So, here are seven functional fitness-style exercises that will completely change the way you look at the old belt-drive cardio machine. Work them into your workout piecemeal or, even better, run through them all in succession for a full workout. Just perform each exercise for 45 seconds, rest for 15 seconds, and repeat for three to five rounds.

Side Shuffle

Set the treadmill to a low speed—3 to 4 miles per hour (mph) is great to start. You can kick it up to 5 or 6 mph once you’re comfortable. With your body facing to the right, shuffle sideways, as though you're moving to the left. Keep your knees bent slightly, don’t let your feet cross, and hold the railing loosely for stability. “If you find your groove, you can let go,” says Rachel Southard, director of personal training operations for Anytime Fitness in Woodbury, Minnesota. After shuffling for 45 seconds, recover with a slow 15-second walk. Then repeat on the other side for one round.

Bear Crawl

Set the treadmill to a low speed—somewhere in the 2.5 to 3-miles-per-hour range. Then lower into a plank position over the belt, with your hands and feet on the non-moving sides. When you’re ready, carefully place your hands and feet on the moving belt and start your crawl: Alternate between walking forward with your left hand and left foot and your right hand and right foot. Keep your back flat and your core engaged until the 45 seconds are up.

Sandbag Run

Grab a 35- to 60-pound sandbag and rest it across your shoulders. Set the treadmill to a speed between 6 and 9 miles per hour and start moving. If that’s too easy, increase to a 75-pound bag, says Kris Cueva, a certified personal trainer at Burn 60 Studios in Los Angeles. The extra weight challenges the body and, unlike a traditional treadmill run, brings your upper-body into the workout. The weighted-down will help you become more functionally fit- just think how easy carrying groceries will become!

Leg-Crushing Burpees

Begin in a plank position at the end of the machine, with your hands on top of the treadmill and your feet on the ground. Perform a push-up and jump to standing, just like you’re doing a regular burpee. Then, jump a second time so that you land on the treadmill, and quickly jump back down to standing position and return to a plank. That's one rep. Burpees are a full-body movement that increase functional fitness ten-fold.

Inverted Rows

Unless your treadmill is pushed against a wall, you can use it for one of the best back-muscle exercises. Start by sitting on the front of the machine with your head under the dashboard. Reach your hands up and grab whatever handrails are above you. Now extend your legs out in front of you so that your body is at a 45-degree angle and you’re looking up toward the ceiling. (Don’t worry—the treadmill will hold you). Pull yourself up until your chin is just couple inches from the bar, and then lower yourself slowly until you’re back in the starting position. Continue for the full 45 seconds.

Walking Lunges

Set the treadmill to a slow speed, somewhere between .5 and 1.5 miles per hour. “Start by holding onto the rails and take a big step forward with your right foot, lowering your left knee toward the ground,” Southard says. “As you stand up, step your left foot all the way forward in front of the right foot and lower your right knee down and repeat.” You knee should stop just before it touches the belt. The moving treadmill will keep you honest, making sure your speed doesn’t drop once you start getting tired.

Pushup to Pike

Settle into a high plank position at the end of the treadmill with your arms on the belt and your legs extended on the floor behind you. Do a push-up and then shoot your hips up into a pike position, like downward dog in yoga. Hold for one second, and go back into the push-up, and finally, return to high plank. This multi-bodypart movement will help increase your functional fitness.

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