Since the mid-1980s, heart rate monitors have revolutionized the way athletes train. In the early years, only a handful of elite runners used this nascent technology to help them take the guesswork out of the training equation. In the days before HRMs became just one more tool in an athlete’s arsenal, most runners relied on taking their pulse manually, or on perceived exertion, to determine the intensity of a given workout.
Until recently, most heart rate monitors used by runners, no matter how simple or technologically advanced, have consisted of the fairly standard one-two combination of a wrist receiver and a chest strap transmitter. In November 2004, Mark of Fitness introduced a heart rate monitor that uses different technology than the standard chest strap/watch combo. Worn like a watch with a small cuff extending up to and around the base of the index finger, the MF-180 ($119.99) is essentially a plethysmograph—a monitor that reads the changes in reflectivity of the skin as your heart beats. This technology is widely used in scientific laboratories to measure all kinds of bodily functions. In addition, the MF-180 uses digital signal processing and error-correction technology to ensure accurate readings.
There is a bit of a learning curve with the MF-180, although setup is fairly simple. The instructions it comes with are easy to follow and include a quick-start cheat sheet along with a full instruction booklet for easy reference. It can, however, take a few tries to get the finger cuff adjusted to obtain the most accurate and continuous reading. Because the monitor measures the changes of light caused by the blood flow in the capillaries near the skin, anything that restricts blood flow or skin transparency can influence the reading. Cold weather can often impact the monitor’s function. Hands should be well warmed up before an accurate reading can be taken. When it is very cold, jogging in place for a minute or two usually takes care of the problem.
Because of its very basic operation and no frills functions, the MF-180 is ideal for those just beginning to train with a heart rate monitor. Besides measuring beats per minute, it has a clock, alarm, stopwatch, and calories burned functions. The MF-180 is also an attractive option for runners who have problems with the chest strap of a conventional monitor. Some very thin athletes have difficulty keeping a chest strap in place, while many women experience chafing around and under the chest strap. In addition, athletes with very low body fat have reported problems getting proper contact with a traditional chest strap.
The manufacturer expects this technology to be available in late fall 2005.
