Heart rate monitor

The Heart Rate Monitor: Why it's useful to you

In order to produce energy, your body burns oxygen and fuel, much like a combustion engine. The body will yield mechanical energy by way of its cardiovascular system which delivers oxygen to the skeletal muscles, that oxygen is then used to burn fuels such as carbohydrates and fat.

When you work out hard, your aerobic systems become overloaded, which forces your body to change because of the demands placed upon it. As you rest, your body changes in order to make you more physically fit. Thus, when you work-out on a regular basis, your body improves its cardiovascular and muscular functions. Your heart will work more effectively and thus become stronger. This also causes your skeletal muscles to better remove oxygen from your bloodstream. The mitochondria boost their enzyme systems in order to oxidize fuels within the muscle cells. These symptoms and changes will occur gradually. You must push yourself a little harder for continued improvement so that you will persist in overloading the systems. That is why as your body adapts to your work-out routine, it requires more difficult work-outs to keep improving.

One way to determine if you are training at the correct level is by the rate of oxygen that is burned in the muscles; this is the best indicator of the results of your aerobic work-out. However, this procedures requires specialized testing facilities as well as costly equipment. Samples of exhaled air are taken as the person runs on a treadmill while the heart rate and volume of the inhaled and exhaled air are computed, and the oxygen concentration can be determined. You can establish what the muscles have consumed to burn fuel by taking the difference between the amount of oxygen breathed in and out during the testing procedure. The rate of oxygen consumed (in liters per minute) is the VO2. This testing can be accomplished at increasingly more difficult levels until the person maxes out. VO2(max) is the highest rate of oxygen consumption.

The best way to determine the threshold below when no additional gains can be accomplished in aerobic exercise is to allow for a pace where you can carry on a casual conversation during your workout, which would be about 55% of VO2(max). If you are above this level you are overloading your cardiovascular and muscular systems to bring about progress. Since you could not possibly take such cumbersome equipment with you on the road, you need to find another way of determining if you are above this level in your workouts. Use the heart rate method to measure the VO2 because the relationship between percentage of maximum heart rate and the percentage of VO2(max) is conventional and is separate from age, gender or fitness level. For example, 55% VO2(max) matches about 70% max heart rate. Therefore, when you have established your maximum heart rate, you are able to monitor your workouts. The max heart rate for the aerobic training zone is normally between 70% and 90%.