I bought a Polar Heart rate Monitor!!! And am getting a tad obsessed! I have it on right now and can tell you that I am doing 98 bpm (beats per minute). I cracked 180 bpm while walking my DS to school this morning!!!! Pushing the pram up a steep hill. I know it's high... I have an over active thyroid which makes my heart go faster than most peoples. When i relax though it can get as low as 66 bpm. So it really varies.

I bought a mid range one... $199. Calculates calories and has OwnZone. It's red and has a pretty design framing the LCD reading that matches my diary! LOL Oh and it's comfy like MG said. Highly recommended