On the other hand, it's now possible to plot and analyze an amazing amount of data, thus opening new doors to the adventurous cyclist. A few units offer heart rate monitor features in addition to basic cycling data. A sensor is strapped around the cyclist's sternum, where electrical impulses are picked up by small diodes. The data is wirelessly sent to the computer, where the heart's current effort is displayed in beats per minute. Cyclists in training can use this data to see the true level of exertion as opposed to perceived effort.
Some units offer PC interfaces.
Hours, days, or months of data can be downloaded into a computer for later analysis. This is a pricey option and isn't of much use to the casual cyclist. For racers and endurance athletes, this training information can mean the difference between a first place and last place finish. Combine a HRM with a PC downloading unit and you get a training device capable of plotting physical exertion against the heart's reaction. Repeated running of the same course over time will reveal the body's level of training.