Optical heart rate technology has become very popular over the last 12 months, appearing in everything from dedicated sports units like TomTom’s Multisport Cardio watch to everyday devices like LG’s G Watch R.
It’s popular because it does away with the chest strap that some people find uncomfortable and irritating, instead monitoring heart rate constantly at the wrist through a sensor in the back of the watch.
It works using photoplethsmography which, in simple terms, is a way of detecting how much newly oxygenated blood is passing under the skin. It’s a totally different method from chest straps, which use electrocardiography to monitor the electrical activity of the heart.
The main issue is that there have been questions about the accuracy of optical heart rate monitors, and their uptake speed is generally slower than that of their chest-strapped cousins, too. Apple say they’ve improved upon the existing technology in their watch, but whether it’s quick and accurate enough to make it a proper training tool and a viable option to other, more established heart rate monitor, is something that we’ll be keen to find out.