If used properly, a heart rate monitor will help you train more efficiently and smarter, getting you up to or closer to the podium at your races.
If you just use it as a cool new toy to see how high you can get it to register on your hilly run or to compare with your training partner's heart rate, it will not benefit you at all and will eventually end up collecting dust in the drawer.
A heart rate monitor is a great tool to non-invasively find out what is going on inside you. Your heart rate does not lie and, with the aid of a monitor, you can tell exactly how your system is responding to your training session. A heart rate monitor helps take the guesswork out of your training; otherwise, you only have perceived effort to gauge your training.
How do you determine your heart rate training zones?
Each person's training zones are very individual and need to be determined before using a heart rate monitor to effectively help you while training. Your maximum heart rate is the highest heart rate you can achieve. It is completely specific to you and is not trainable.
There are several formulas out there such as 220 minus your age to determine your maximum heart rate, which in turn is used to determine the optimum heart rate to train at. This and other formulas using age, resting heart rate and your current level of fitness are predictions and will only work with a small majority of people.
It is best to determine your training heart rate zones without the use of a generic formula. You can do this by performing a max heart rate test in each sport, but this may sometimes seem like holding a gun to your head and could be dangerous.
A better way is to determine your anaerobic threshold (AT) rather than trying to find your maximum heart rate. By finding your AT, you can then define your training levels using this number. Finding your AT is as easy as wearing your heart rate monitor at your next 10K road race, 30-40-mile bike time trial, or by checking your heart rate throughout a hard 30-40 minute swimming set at the pool.
Most athletes can maintain just at or slightly above their AT throughout a 30-45 minute effort. There are also several coaches and physiology labs that can perform a simple AT test on a wind trainer or treadmill.
Like maximum heart rates, AT is also specific to each individual, but is trainable. Your AT is the point at which enough anaerobic metabolism occurs for more lactic acid to be produced than can be rapidly cleared from the body. This occurs from 65-95% of your maximum heart rate, depending on your fitness level.
You can recognize this level as that point where breathing becomes labored but maintainable. If you continue to increase your pace, you soon will reach failure and will have to slow down to continue.
Your AT will be different from sport to sport. On average, your running AT will be higher than your bike AT and your bike AT will be higher than swimming AT. How much this differs and which discipline engenders the highest AT will depend on which sport you have more experience in.
After you find your AT, what do you do?
Remember that your AT differs from sport to sport. Break your heart rate into three zones. Take the number and use it to train your AT system, increasing its efficiency so you can go longer, faster without tiring out. Training zones are as follows:
Zone 1: Aerobic sessions, 30-50 beats below your AT
Zone 2: Threshold training, 5-15 beats below your AT
Zone 3: Anaerobic (interval) training, 5-10 above your AT
How much training should you do in each zone?
This depends on the time of the year and what length of race you are preparing for. Earlier in the season, you want to keep the majority of your training well below your AT (Zone 1).