Walking is excellent. It may never get you as fit as doing tons of Imaxes will, but it will certainly help you create better health and not at the cost of your joints.
To make it work for you, apply the same principles to walking as a runner does to running. Vary your workouts so that you do steady state cardio workouts, intervals, hill work and short bursts of concentrated speed. This not only helps you maximize the calorie burn but will help cut down on the boredom that enters when one sport provides all your cardio routines.
I use the treadmill to powerwalk and I alternate between steady state walks at 5 mph for 6 miles, and interval sessions after a 5 min warm up, where I alternate speed sessions of a quarter mile lap in length, moving at 5 mph, the next at 5.2 mph, the next lap at 5.4 mph, the next at 5.2 mph, and the next at 5 mph again, moving up and down a pyramid to keep my heart rate up and guessing.
After this for about 3 miles (I always do 6 miles per session, never less), I then switch it up to hill intervals for the last 3 miles, alternating speeds and inclines to vary the challenge to the body. High inclines put more stress upon the glutes and quads, less upon the calves and hamstrings, at least for me. I might do 4 mph and incline of 15, the max on the machines I use, or speed of 4.4-4.8 mph with incline between 6-12. I vary it depending upon level of energy and the beat of the song I'm listening to. At the moment Madonna's "Confessions" is providing excellent songs to work inclines. The first 7 songs or so vary tempo between 4 and 4.4 mph, so I can really wack up the incline to the max and the beat just keeps me going, no matter how tired I feel.
So, yes, walking can be all the cardio you need, depending upon what your needs are and what your fitness goals are. If you want to be a supreme athlete, only running will do it for you, but if you want superior fitness, above that of the average Joe, power walking can help you get there. You just have to be focussed and make it work for you: no endless, mindless walking at a slow pace before the TV on a treadmill or walking chatting with friends. Neither of the latter will get the job done, even if they are both very pleasant!
Clare
