Break a Sweat With 17 Quiet, Bodyweight Cardio Moves That Won't Annoy Your Neighbors

The wall sit is a step up from a traditional air squat, said Amanda Murdock, ACE-certified personal trainer and director of fitness at Daily Burn. "See how long you can hold it," she suggested. If you want even more of a challenge, hold weights or weight substitutes while you squat.

• Stand with your back against a wall, placing your feet about two feet in front of you. Feet should be hip-distance apart.
• Bending your knees, slide your back down the wall until your knees are at 90-degree angles. Your knee joints should be over your ankle joints, so you may need to inch your feet farther from the wall to create proper alignment. Don't let your knees fall into the midline of your body or sway outward.
• Hold for 30 to 60 seconds, then stand up.