For many years I kept myself fit by Power Walking (i.e. Walking fast, erect torso, arms about horizontal but bent ~90%, pump arms forward til elbow parallel to side of chest, all while taking fast but short steps, wearing 1.5 to 3lb.s wrist weights). In pole or Nordic walking you substitute poles or wooden walking sticks for the weights. It worked very well to provide a great aerobic workout and a moderate core & upper body exercise.

Google "Nordic (or pole) walking instructional". You will find several instructional videos, articles, & blogs, etc. I'd suggest purchasing the Leki spring cushioned poles with the bent hand holds. Not cheap, but they help with posture due to the grip angle and the shock absorbing quality of the springs lessens the upper body soreness caused by striking the ground when "planting" the pole. If you want purpose built wood poles, try the Brasos Walking Stick site.

Don't pay any attention to those who will give you strange looks or sniggering comments. An equal number of folks will be fascinated and will ask you to explain your methods, especially if you frequent the same routes. Enjoy.