Beginner: With your back against the wall, slide down as though you’re lowering into an imaginary chair. Count to 5, return to standing, and repeat 8 to 10 times. “This wall-sit works your quads and glutes to keep legs strong and steady without aggravating your back, or making you get on the floor,” says Kaehler.
Moderate: Increase the count to 30, adding light hand weights or a band. While you’re sitting, do a few Kegels (tighten the muscles of your vagina -- like you’re holding back a stream of urine -- then release). “You might as well get used to multitasking now,” Kaehler jokes.
Advanced: Move away from the wall, hold onto a chair and squat down for 2 counts; hold with a Kegel. Return to standing; repeat 12 times. (Away from the wall, you’re recruiting additional muscles to help with balance and stability.)