Today's heart rate monitors have made it easier for athletes of all levels to get the same feedback they would get from a high-priced trainer. It's like having a personal coach strapped to your wrist. Until you get a heart rate monitor, you measure your effort by time or distance. With a heart rate monitor, however, you can now get a better indication of effort. And it comes from the heart. Literally. Your heart will tell you how hard you are exercising, how fit you are, and how you are recovering. Knowing these things will make you training more effective. A heart rate monitor consists of a watch unit worn on the wrist and a chest transmitter strap. The watch can be worn as a regular sports watch, and when not connected to the transmitter strap, will still give you time of day, alarms, stopwatch functions, etc. The chest transmitter senses your heartbeat and constantly transmits that information to the watch. There are some units that don't use a chest strap. These normally measure the pulse when the user places two fingers on each of two buttons on the watch face. Pulse is a decent measurement, but does not give you the same level of continual information a chest strap will. One of the first things you need to know when using a heart rate monitor is what your maximum heart rate is. The standard formula used is to subtract your age from 220. You can then calculate at what percentage of maximum you should be exercising at. When doing cardiovascular training, research says exercising at 60-70% of your maximum heart rate will be best for fat loss and to build endurance, while exercising in the 70-80% of maximum range will increase your fitness. There are a number of features available in modern heart rate monitors. Some are more useful than others. Of course, a constant measurement of heart rate is vital. It is helpful to be able to set zone alarms or otherwise be able to see where you are compared to your maximum heart rate. Some will do all the calculations for you, telling you when to ease up or to pour it on, depending on your workout for that day. Others will just show a heart rate number, and you will need to know what the upper and lower limits are for your workout. It pays to shop around for the features you need, and not buy a lot of things you don't need. Too many extra features may confuse you and discourage you from using your heart rate monitor regularly. That's bad. It's better to get something simple that you can commit to using regularly. Still, if you can handle it, there are some sweet features available. Whatever heart rate monitor you choose, use it regularly. It will provide you so with much detailed information about your training; you'll wonder what you ever did without it, and you'll never want to be without one again.