http://www.runningforfitness.org/calc/heart-rate-c... web page on heart rate zones hеаrt rаtе zоnе heart rate zones web page on heart rate zones hеаrt rаtе zоnе hеаrt rаtе zоnе web page on heart rate zones web page on heart rate zones web page on heart rate zones RunningforFitness.org: Heart Rate Zones hеаrt rаtе zоnе Running for Fitness: Heart Rate Zones this handy chart web page on heart rate zones