Why you need a heart rate monitor!!
Heart rate monitors have quickly become the latest technology device to bring the standard of running to the next level! GPS watches used to measure distance/time ran are now incorporating heart rate monitors.
Getting tested!
When you first buy a heart rate monitor it is important to get tested first. Testing is done to to find where your fitness lies and discover your heart rate zones. It is usually done on a treadmill where a mask is put on your face and a heart rate belt is put around your chest as you run on a treadmill!
Heart rate zones vary person to person, each zone corresponds to a training pace, so for example 160-175 bpm might be threshold pace, so when doing threshold runs so are recommended to stick to that heart rate!
Listening to your body!
Once you know your different heart rate zones and paces, you are in a good place to begin training! You can easily tell if you are going too fast/slow on your easy runs and get the most out of your tempo runs as your run right along the lactate threshold!
Heart rate monitors are great as they allow you to listen to your body when training. If it windy and uphill, you don't have to worry about pace, just your heart rate which will obviously be working harder in these conditions. It is a great tool to prevent over training and keep your training very structured!!
Sometimes you're better off free?
However I wouldn't run with heart rate monitors all the time.... In the beginning you could definitely use them to know what feels right relative to the training zone. But after a while you know what it feels like and you can definitely do without it most of the time.
Constantly glancing at a watch is unnatural and unnecessary, running free is the most fun and not pressurizing, the way running should usually be! I would recommend them for some easy runs just to keep in check and on most tempo/threshold runs!