Once the preserve of runners, GPS watches have become popular with cyclo-cross riders, mountain bikers, triathletes and now road cyclists. The latest generation not only do the job of a head unit but are fitness trackers and more.
Among the many upgrades that have appeared since the Casio PRT-1GP (the first GPS-enabled watch) is the optical heart-rate sensor, which is designed to eliminate the need for a chest strap.
But many athletes and coaches have found some of the data from these sensors to be less than accurate. Manufacturers have been working on sensor quality but can the data be really trusted?
How sensors work
According to a paper which investigated sources of inaccuracy in wearable technology, “Heart-rate measurements from wearables are derived from photoplethysmography (PPG), an optical method for measuring changes in blood volume under the skin.”
Put simply, when your heart beats, blood moves around the body in pulses. These pulses mean that blood volume at various points in your body changes a little with each beat. Heart-rate can be deduced from measuring the time between these changes. Chest straps work differently: they detect electrical signals from your heart and tend to be more accurate.
The science
This story is from the February 23, 2023 edition of CYCLING WEEKLY.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber ? Sign In
This story is from the February 23, 2023 edition of CYCLING WEEKLY.
Start your 7-day Magzter GOLD free trial to access thousands of curated premium stories, and 9,000+ magazines and newspapers.
Already a subscriber? Sign In
"We tore around the Sydney suburbs at 60kph in a terrifying, feral pack"
Fast, furious and furry tales from Australia
RIDDEN AND REVIEWED BROMPTON G LINE £2,499
A Brompton for running riot in both town and country
How do different gravel conditions impact your tyre choice?
There are a myriad of tyres on the market but selecting the right one is easier than you think
FEAST OF SWEDEN
Soon after landing in Gothenburg, I began to realise how little I knew about Sweden.
THE WORLD'S GREATEST GRAVEL EVENTS
Globe-trotting gravel racer Joe Laverick chooses his eight favourite events, from coastal Wales to the wilds of Kenya
THE CALL OF THE WILD
Tempted to embark on a long-distance bike adventure? Let former round-the-world record holder and author Julian Sayarer inspire you to strike out and hit the road
Saint Piran accused of using non-UCI legal bikes
Cornish team also alleged to owe former staff tens of thousands of pounds
JOE LAVERICK GETTING INTO THE FEED ZONE
I've ridden through hundreds of feed zones in my time racing a bike.
Lowden not ready to stop after retirement
Former Hour record holder eyes UK time trial scene
Pogačar makes history (again) at Lombardia
Slovenian makes it four in a row at the late-season Italian Monument
