DO: Think about keeping your head, shoulders, abs, knees and toes in one line as you walk. Draw your belly button in toward your core. Push off your big toe (until it bends) with each step and keep toes facing forward. (If you have tight hip flexor muscles, your toes probably point out, so try to retrain them to face forward.) To avoid unnecessary shoulder tension, swing your arms loosely by your sides. To increase the burn when you're walking for exercise, hold your arms at a 90-degree angle and keep your hands free (clip your music player to your shirt, buy a belt that will hold your water bottle and store your keys in a jacket pocket).
THE PAYOFF: Standing up straight while walking makes your body work more efficiently as you move throughout the day.