Are Treadmill Heart Rate Sensors Accurate? (Answered)
By Simon Gould
They're not accurate, but there are ways you can get an accurate measurement. 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.
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 to treadmill sensors?
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 a treadmill. The reading will be displayed on the console together with speed, distance etc. The leading company for heart rate chest straps are Polar*. Some treadmill brands offer them free with particular models.
Heart rate numbers you should see
These numbers were obtained from experts at the Mayo Clinic and Harvard Medical School. As a guide, I'll show you the numbers you should normally see as your heart rate. They are measured in beats per minute. This is recognized by medical communities around the world.
The number most helpful when using your heart rate for exercise is the maximum heart rate. This can be difficult to measure and all kinds of medical equipment is needed. But for a guide and one useful for exercise, the easy way of calculating your maximum heart rate is taking 220 minus your age. So a 40 year old would have their maximum as 180 beats per minute.
So the number you should see is between 60 and 180 if your age is 40. If your exercise is high in intensity, you could be working out to 80% of maximum which is 144 beats per minute.
- Resting heart rate - 60 to 90. Over 90 is considered high. Someone with a high level of fitness may have a resting heart rate significantly lower than 60.
- Heart rate while standing still - 10 to 15 higher than resting
- Walking heart rate - 110 to 120
- Aerobic exercise heart rate - 60% to 80% of maximum
If you were using your heart rate as a measure of how hard you're working out, I wouldn't rely on a hand grip pulse sensor number at all. You have to change posture just to be able to hold onto them. The number can change and vary wildly. If you don't have a heart rate chest strap, it's best to focus on how you feel.
Optimum heart rate is when you're exercising in the most efficient way. You will build fitness the fastest and burn the most amount of calories for the effort you're putting in if you're in that range. If you're using the incline, your heart rate will go up, same if you're brisk walking. Some running coaches swear by using the heart rate to improve athletic performance.
When you need to be concerned is when your heart rate is too high from a gentle activity. If you're not exerting yourself you shouldn't feel out of breath. You shouldn't be struggling if you're only walking. You shouldn't feel your heart pumping through your chest. Stop if you feel this way and seek medical assistance.
Wrist worn fitness trackers
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 to within 1% to 9% (source).
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.
So the hand grip pulse sensors you see on treadmills aren't accurate and shouldn't be used as a measurement. Heart rate chest straps and fitness trackers can be considered accurate and are the way to go if you want to incorporate heart rate training into your routines. They can be useful for making sure you're getting the most out of the workouts you do.
Thinking of buying a treadmill? Here's my favorite, I always recommend it when asked*