Lee, I believe your numbers are about right. I calculate about 2400 strides per mile. At 240 strides per minute, that is the equlivant of a 10 minute mile. That is 4 strides per second. Up and back twice per second. That is about what I am doing. It has both a Polar heart rate monitor in the grips of the arm pulls and a Polar chest strap. The chest strap is the most accurate. At 240 strides per minute x 10 equals 2400 per each 10 minute time. Thus a 10 minute mile. My Max I believe is 220-68 = 152 At the end of the 30 minute workout my HR is about 140, but the average for the entire workout is about 120. Does this add up to you?