Is Garmin Forerunner 110 accurate about calories burned?

EatWholeFoods

I do 70 minute work outs and the heart rate monitor says 129-150 beats the whole time and at the end it says I burned 360 calories in 74 min. with an avg heart rate of 133. Is this accurate? Most equations say I burned 500-600 or more in 75 min. I entered my height, gender, etc into the hrm.