The 2008 Drop a Jeans Size Workout Plan

This plan is based on intervals -- key to zapping more calories both during and after a session. "Challenging your body and then letting it recover helps you become more efficient at burning fat," says trainer Kristi Molinaro. You'll see the proof -- we did! -- in your sleek new physique. Then shop for jeans -- a size smaller!

This workout is based on combinations of cardio and strength exercises. Do each move for the given amount of time (30, 60, or 90 seconds), following the appropriate variation for your fitness level. If you can't do an exercise the entire time, jog or march in place. Go from one move to the next as quickly as possible (the strength moves will give you a chance to catch your breath). The entire workout takes about 40 minutes.

Complete this routine three times a week, but not on back-to-back days; you need time to recover. Two or three days a week, do whatever form of cardio you love -- walking, running, swimming, cycling -- for about 45 minutes at an intensity that is sustainable but leaves you somewhat breathless.