Are Treadmill Heart Rate Sensors Accurate?
By Simon Gould
Testing your heart rate while running has long been known to provide essential data for runners of all abilities. The information contained can vary enormously between different runners at different fitness levels. For example a resting heart rate of someone who's very fit is low. A running heart rate of a young runner is very high.
Elite athletes like footballers wear a heart rate chest strap as they train with their respective squads. This give the club doctors and coaching staff a good idea on how their players are performing. An abnormal heart rate can be a sign of an impending illness so it's a very useful tool for a lot of people.
It was only a matter of time before a heart rate reading was used by hobby runners to maximize their own performances. This would enable these runners to get the most out of the workouts they do. They could see if they're running at the ideal level for weight lost or muscle gain. Both of these can be achieved by using a treadmill.
Treadmill manufactures, who were quick to catch on, started making their own heart rate sensors on their treadmills. Their aim was to finally get heart rate readings that are easily obtained and that the treadmill user could use. It would need to be something that you could easily hold on to while running.
So how do they work?
We've all seen them, the chrome finished handlebars. They are actually called pulse heart rate sensors, because they detect your pulse. You're supposed to grip hold of the bars and 10 seconds later your heart rate reading appears on the console. They can be found on all types of fitness equipment and treadmills in gyms and health clubs.
What they do is detect the heart rate through the skin on your palms and fingertips by interpreting the electrical signals. They take a reading for a short period of time and show it on the read out for you. They only work if they can detect these signals. To do this your hands need to be moist. They don't work if your hands are too dry or too wet.
The reading depends on you keeping your hands very still. This is not the easiest thing to do if you're running especially at peak intensity. Holding the handlebars also affects your posture. You can't run naturally if you have your arms placed in front of you and not swinging naturally by your side.
The problem is you need an accurate measurement of your heart rate in order to use it effectively. The pulse heart rate sensors do not give a reliable reading for multiple reasons. One is the movement of your hands and body affect the reading. There are other ways of measuring your heart rate more easily and accurately than these sensors.
What are the alternatives?
Technology has advanced quite a lot since these pulse sensors were around. The most common are heart rate chest straps. These can be very accurate and are used by professional sports people and their coaches and doctors. They're easy to use, they are elastic and you place them just below the chest.
The straps transmit the heart rate to the receiver. The receiver can be a watch worn by the person wearing the strap. Or they can be the very treadmill you're running on. This information updates by the second for the runner to use as they require. The leading company for these devices are Polar and their heart rate monitors are reasonable in price.
Technology now has the optical heart rate monitor. These come as bands that fit around the wrist. They have 2 optical sensors on the inside of the band to read your heart rate. An accepted and published scientific study in 2016 tested a range of these watches and found the heart rate readings to be accurate (source below).
They not only measure your heart rate but also sleep, activity, calories burned and more. Calories burned is more of a guess but it's still good to get information about your activity levels. There are a few companies that make these new kind of heart rate bands. The most common is Fitbit but also Apple Watch and Garmin have entered the field with their own watches.Source: Matthew P. Wallen, Sjaan R. Gomersall, Shelley E. Keating, Ulrik Wisloff & Jeff S. Coombes journals.plos.org/plosone/article?id=10.1371/journal.pone.0154420. Public Library of Science, May 27, 2016.