Getting the most out of a walking program involves more than throwing on some clothes and stepping out the door. It's important to first take a minute and prepare your body.
Start by standing up straight. For proper posture, tuck in your behind by rotating your hips forward just a little. The goal is to keep you from arching your back. Then, shrug your shoulders once to relax them just before you head out the door.
Don't lean. Leaning in any direction puts unnecessary strain on the back muscles.
Practice breathing by pushing your stomach out as you inhale and sucking it back in as you exhale. Look at your chest and abdomen while you're breathing. Now place one hand on the part that rises and falls the most during each breath. If your abdomen is moving more, you're doing fine. But, if your chest is doing most of the moving, you're not utilizing the lower part of your lungs.
When you start to walk, the heel of your foot should touch the ground first and then roll your weight forward. Push through your big toe while keeping the other toes relaxed. If you want to work the glute muscles (your butt) even more, take short quick steps instead of the long strides.