By shining a low-intensity light through your skin, the sensor can read fluctuations in blood flow beneath the skin and determine your heart rate, as well as more advanced metrics like blood oxygen - something that has come into the spotlight during the COVID-19 pandemic.Īs you're likely to be wearing a watch or fitness tracker anyway, it makes a lot of sense to whack a heart rate sensor on the bottom of the case which will be pressed up against your skin. Optical heart rate has been around for many years in the medical setting with the finger clips that read heart rate through Photoplethysmography (PPG). With the proliferation of fitness trackers worn on the wrist - such as Apple watches, Fitbits and the Wahoo ELEMNT Rival - we have also seen widespread adoption of optical heart rate monitors.
As far as how long they last, it seems to largely depend on the individual, there are some people who will go through a chest strap every year, while others (like this writer) only have to replace them when the elastic in the strap itself finally gives up. Sweat sneaking past the weatherproofing on the battery door can also be an issue. However, these snaps are usually the Achilles heel of the chest strap as the constant exposure to sweat can cause them to corrode to the point of interference with the signal coming from the electrodes.
Most use a detachable pod that houses the hardware to broadcast the ANT+ and Bluetooth signals, a coin cell battery and sometimes accelerometers, gyroscopes, and perhaps a bit of memory, which can record running metrics and even full activities. Many people have a love-hate relationship with chest-based heart rate monitors, as the elastic strap can be uncomfortable, or slide down over the course of a ride.
MIO HEART PRO MANUAL
We’re sure that deep within an owners' manual that never came out of the box, there are best practices for wearing a chest strap, but it doesn’t take a rocket scientist to figure out where it goes, and there also seems to be a pretty wide range of real estate where it will take a reading.