Sex Positions That Double as Exercise

Bridge

With the bridge, the woman is facing upward, using all four limbs to hold her body weight off the bed. All our sex experts agree: this pose is not for the weak. Or, as Britton puts it: "Oh, God, she better be yoga-ing five days a week or training as a gymnast."

"This is a highly advanced position," Britton says. "She needs to stabilize herself so as he's thrusting in and out, she doesn't crash."

Even if you pile a tower of pillows under your back to help support your weight (which Britton recommends), you'll still definitely be working your buttocks and inner-thigh muscles, says Fulbright. "This is going to work all of it -- her biceps, triceps, abs, glutes, quads, calves. Unless she's really strong, she shouldn't expect to hold this position for long."

Adds Berman, "If you're going from cowgirl to this position, your butt will start burning after five minutes."