Updated: May 07, 2008

Believe it: This 20-minute full-body routine from Contributing Editor Petra Kolber—with six- and nine-month fitness boosts—is the only workout you'll ever need. Just repeat two or three times a week and combine these moves with 30 minutes of cardio, three times a week.

• Lateral Lunge With Biceps Curl
• Hip Hinge With Triceps Extension
• Figure Eights
• Lunge With Overhead Press
• Prone Leg Raise With Ball