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
Esta historia es de la edición February 23, 2023 de CYCLING WEEKLY.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor ? Conectar
Esta historia es de la edición February 23, 2023 de CYCLING WEEKLY.
Comience su prueba gratuita de Magzter GOLD de 7 días para acceder a miles de historias premium seleccionadas y a más de 9,000 revistas y periódicos.
Ya eres suscriptor? Conectar
CLASSIC BIKE COLNAGO SUPER
A trailblazing bike immortalised by Merckx and Saronni
"Strava activities are the only way I know some of my friends are still alive"
...or that Bernard is doing his weekly shop
AN EXPERT'S TAKE ON... SADDLE SELECTION
Crucial advice to guide your next purchase
JUST A NUMB#R?
Approaching a landmark birthday, Charlie Graham-Dixon explores how ageing affects cycling performance and what can be done to stay ahead of the curve
RURAL PERIL
More UK cyclists are killed on rural lanes than on busy city streets. Rob Kemp investigates why and what can be done to keep us safe while riding in the countryside
A BLESSED RIDE THROUGH THE FOREST OF BOWLAND
Forgoing cloak, cassock and cross, Trevor Ward goes in search of the holy roads that helped make a Tour winner
Dame Sarah Storey claims road and 19th gold double
More success for Team GB's Paralympians in Paris, but Storey slams women's time trial course
Roglič matches Vuelta win record
Slovenian takes fourth Tour of Spain title after hunting down O'Connor's lead, writes Adam Becket
Williams crowned Tour of Britain champion
Welshman leads home resurgence at the stage race to crown an Israel-Premier Tech clean sweep, reports Tom Davidson in Felixstowe
CLASSIC BIKE CLAUD BUTLER OLYMPIC ROAD
Iconic British brand's Holdsworth-era road bike