Surprise: Your average walk is not a workout for your derriere. "Walking on level terrain does not require you to fully contract the gluteal muscles, so it doesn't do much for toning them," says Wayne Westcott, PhD, fitness research director at the South Shore YMCA in Quincy, Massachusetts. That's because the work is mostly in your quads and hamstrings.
The Routine
"For the best butt toning on two feet," says walking pro Tina Vindum, walk for 5 minutes, do one of the supereffective shapers shown here, then repeat until you've done all four exercises. (If your route has hills, tackle these moves every time the path hits an incline -- or a set of stairs -- for maximum butt-blasting benefits.)