The device used to measure the heart rate of an athlete is called a heart rate monitor. This usually consists of a transmitter strap on the chest and a device that is in the middle of the chest, attached to the strap itself; the latter can be both a watch and a small computer. In the most recent models, it is allowed to use a smartphone to monitor palpitations, in addition to controlling any sudden changes in it. Making use of this small system, it is possible to know the physical condition in which a person is; however, it is much more common for this physical exam to be performed on athletes.

Heart rate monitors are devices with a somewhat simple operation. The band that is placed on the chest contains electrodes that are capable of perceiving all the pulsations, which will later be transmitted by means of a radio signal, so that the receiver is capable of determining the heart rate.

Sometimes the electrocardiogram is also called a heart rate monitor. Although this is not entirely wrong, the latter has strictly scientific purposes, it is also responsible for giving an exact representation of the electrical activity on the surface of the heart, obtained in the chest. These are the main elements that come into play when diagnosing cardiovascular diseases, metabolic disorders or predisposition to sudden cardiac death. It is also useful to know the duration of the cardiac cycle. Another difference between both devices is that the electrocardiogram is much larger than the heart rate monitor, to which is added the complexity of handling it.