Adding poles and doing Nordic walking, compared to walking without poles, burns about 20% more calories. This is with the same perceived exertion. This means you can burn significantly more calories without feeling you are working harder. (Ref. Research Quarterly Exercise & Sport, 2002 Sep. 73(3)296) If you improve your technique and/or go faster, you can expend more energy and increase calorie burning even more in the same workout time.