We have both recently purchased heart rate monitors. Looking back our runs were fine without them…but WOW have they made a difference in training.
Here are some reviews of HRMs : http://www.consumersearch.com/heart-rate-monitors
Joanna has the Garmin Forerunner305 and Allison has the Polar F11.
Using these we are both able to track our heart rate levels throughout the run, and also calories burned. There is also a timer function to see how long you ran.
Joanna’s favorite feature on the Garmin is the GPS. It tracks her distance via satellites and when she gets home she plugs it into the computer and it outlines the actual route that she ran = pretty amazing. She can save all her runs and even compete against her previous times.
Allison really likes the size of her polar. It is small and less bulky, so it looks like a normal sport watch.