POLAR Heart Rate Monitor
Heart rate monitors provide a window into the body; they work by sending a wireless signal from a strap worn around the ribcage to a computer mounted on the bike, or to a personal watch or smartphone, allowing you to observe and record in real time how quickly your heart is beating in response to your ride.
Using this information, you can not only monitor how hard you’re working, but also adjust and make changes on the fly to ensure that you’re getting the most out of your workout.
For example, if your goal is to complete a recovery ride, you can use the heart rate monitor to ensure that you are staying within 50-65% of your maximum heart rate.
Relatively inexpensive, incorporating a heart rate monitor into your workouts is one of the most effective things you can do to improve the quality of your training.