Wall sits are a popular exercise for a reason: They do an awesome job working your quads, and even your abs.

But sometimes you need to shake up your routine a little bit, and that's where these variations come in.

In the video above, our fitness editor Eb Samuel shows you seven different types of wall sits that will feel the Burn with a capital B. You can do them as a circuit, or incorporate each move individually into your next gym session to challenge your balance and give essentially every muscle in your body a workout.

Standard wall sit:Slide your back down the wall until your hips and knees are at a 90-degree angle. Your shoulders, upper back, and back of your head should all be flat against the wall, and make sure to distribute your weight evenly throughout both feet. The standard wall sit will challenge your entire core and your quad muscles.

Wall sit with biceps curl:Slide into a wall sit holding dumbbells that are the weight of your choice at your side. Rotate your palms so they're facing you, and curl up, contracting your biceps as you go. Once they're fully contracted and the dumbbells are at shoulder level, hold your position and squeeze your biceps for a second or two. Bring your arms back down slowly for maximum burn, rotating your palms as you go so the backs of your dumbbells touch the wall behind you.

Wall sit with hip adduction:Once you're in position, place a soft med ball between your knees and squeeze them together so the ball doesn't fall. You'll feel this one not only in your quads, but in your adductors as well.

Wall sit with med ball press-out:Fire up your chest, shoulders, abs, and quads simultaneously with this wall sit variation. With a med ball the weight of your choice, press the ball out in front of you and bring it back to your chest in a controlled motion. Remember, the slower you go, the more you'll feel it.

Single-leg wall sit:Once you're in your wall sit, spread both arms out beside you with your palms touching the wall to help keep your balance. Then bring one leg straight out in front of you, making sure your hip is parallel to your knee, and your core is tight. Try holding for about 30 seconds before switching legs.

Wall sit with lateral raise:Grab your dumbbells again to sculpt not only your legs and core, but your shoulders, back, and arms as well. Remember to keep your torso completely centered and stationary, and don't swing your arms out to the side. Instead, keep them controlled as you raise and lower them.

Wall sit with overhead press:You'll work your shoulders, arms, and back with the med ball overhead press. Start out with the med ball at eye level, and raise it over your head until your arms are straight, then bring it back to the starting position. Your core should be tight, and your back shouldn't come away from the wall.