I have a treadmill and Tony littles Gazelle (sprintmaster). Both work great, both give great cardio workouts. When I go on th gazelle, after 10 mins it says I burnt like 110 calories ( I am sweating at that point, its like an elliptical) but after half hour on the treadmill (running for about 10 mins too) it says I used 114 calries. Are these things accurate at all???