Learn to walk correctly (not flat footed "lazy walk") using the ball of your foot to push off, never allowing completely straight lets so stride is not too big (causing too much flex and possible shin splints).

Start with a slower pace for the first five minutes of the walk and then increase your speed to warm up your muscles and heart.

Keep your glutes tightened the entire time (your rear end will lift and abductors and adductors will tone and tighten).

Use your arms to propel you forward (speed without running is the key)!

Keep your fingers bent as if holding a rod (to keep your fingers from swelling).

Hold you abs in but don't hold your breath! You must be "in oxygen"(able to say a sentence without gasping for breath) in order to get aerobic benefit.

Your most important element to watch is cadence, how far you walk will not get great results nor will the length of time you walk, but how long it takes you to go how far. Beginners should strive to take no longer than 17-19 minutes per mile striving ultimately for 11-13 minutes per mile.

Stretching is a must! When walking is done correctly, muscles will be sued that aren't used otherwise. At least five minutes of stretching prior to and after a walk is vital.