I recently got a heart rate monitor with my Garmin and wore it a few times but didn’t know what to do with the data.  Now, I know!  Use this formula if you are a woman to find out your upper and lower limits in beats per minute to optimize weight loss:

206-(your age x 0.88); then multiply the answer by 0.65 to get the lower limit and 0.85 to get the upper limit.

My range is 114 to 149 (which is good news for me!  I was in that range on my runs!)