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Types of Heart Rate Monitors
The types of heart rate monitors are usually classified according to their underlying technologies i.e. how heart rate information is measured and transmitted:
- Wireless Heart Rate Monitor
- Strapless Heart Rate Monitor
- ECG Accurate
- Non-ECG Accurate - Optical Sensors
Wireless Heart Rate Monitor
This type of heart rate monitor consists of a chest strap transmitter and a wrist watch receiver. The chest strap has to be worn around the chest during exercise. It has two electrodes, which are in constant contact with the skin, to detect electrical activities coming from the heart. Once the chest strap has picked up the heart signals, it transmits the information wirelessly and continuously to the wrist watch. The number of heart beats per minute is then calculated and displayed on the wrist watch.
The wireless heart rate monitor can be further subdivided into digital and analogue, depending on the wireless technology the chest strap uses to transmit information to the wrist watch.
Wireless heart rate monitor with analogue chest strap
This is in fact the most popular type of heart rate monitors. The analogue chest strap can usually interface with gym equipment that is heart rate monitor ready. So if, say, a treadmill is already equipped with a wireless receiver that can interpret signals coming from an analogue chest strap, it can display your heart rate directly on its display screen. You actually don't need to wear the wrist watch while you are running on the treadmill as long as you are wearing the chest strap.
There is, however, a possibility of signal interference (cross talk) if other analogue heart rate monitor users are exercising nearby. If that happens, your wrist watch may not be accurately displaying your heart rate.
There is one type of analogue chest strap that transmits coded analogue wireless signals. Coded analogue transmission aims to reduce (but not eliminate entirely) the degree of cross talk while simultaneously preserving the ability to interface with heart rate monitor ready gym equipment.
Wireless heart rate monitor with digital chest strap
The use of a digital chest strap eliminates the problem of cross talk when other heart rate monitor users are close by. The other side of the coin is that it does not interface with other gym equipment. By its very nature, the digital chest strap is engineered to talk only to its own wrist watch receiver and to nothing else.
Strapless Heart Rate Monitor
This type of heart rate monitor consists of just the wrist watch without the chest strap transmitter. It measures the heart rate only when you put your fingers on special sensors on the face of the watch. Therefore it does not provide continuous heart rate monitoring. Because of that, it is unable to yield accurate information such as the average heart rate or the maximum heart rate obtained during an exercise period. It is also a little inconvenient for many exercises, as you have to interrupt what you are doing, put your fingers on the sensors for a few seconds, and wait for your heart rate to appear on the display. This is not always practical for many types of sports.
Note that there are really 2 sub-types of strapless heart rate monitors. The first type of monitors measure your heart rate by detecting electrical impulses. These monitors are very accurate (often called ECG or EKG accurate) and hence they cost more to buy. The second type of monitors measure your heart rate by using optical sensors to detect pulses going through your blood vessels. These monitors based on optical sensors are much less accurate and hence often quite cheap. So please do check and read the manufacturer's specifications carefully if you are considering buying a strapless heart rate monitor.
Not sure which heart rate monitor is right for you? Take a look at the Which Heart Rate Monitor page.
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