I have a Polar heart rate monitor that consist of a chest strap with sensors, a wireless transmitter, and a receiver that sits on my bicycle handle bars. My theoretical max heart rate is 183 bpm using the 220 - age rule of thumb and my resting heart rate is around 60 bpm. My bike rides are around 60 km long and include some hill climbing. My heart rate during a ride normally tops out in the 170s when hill climbing and drops to the 120s when descending for an average of about 155. up until today my maximum recorded heart rate was 183 which seemed to validate the rule of thumb.
Today was different, while descending a hill I noticed that my heart rate was 205 bpm, shortly afterward it dropped instantly to the usual 120s, a little while later it was back up over 200. When I finished my ride my max recorded heart rate was 237 bpm. Through the heart rate changes I felt normal and as far as I could tell by feeling for my pulse in my neck it wasn’t racing. Because the changes were apparently instant and I felt normal my conclusion is that the monitor is giving false readings, but what would cause that? I would have thought that the only false reading it could give would be if it wasn’t picking up all my heart beats in which case it might under read, what would cause it to over read?
False reading. The polar units are good, but every now and them (maybe once or twice a year in my experience) they get a buggy reading. I don’t recall the exact number, but when it happened to me it was in the 230 range. Well beyond what I could do.
False reading; the strap may be getting wet or saggy; different humidity (air, your skin); your bike shirt may be loser/not helping the strap keep the contacts against your skin as effectively; batteries starting to fade; etc… on the mechanical side.
From the paranoid perspective, I first exhibited my A-Fib (Atrial fibrillation - Wikipedia, the free encyclopedia) while hill climbing as an avid bicyclist. If you notice a physical sensation of accelerated heart beat (not just the heart unit reading something high), see a doctor for a checkout.
I find when my hand get sweaty or wet, while I put my hands on the sensors at my gym, the pulse indicator, goes way off. It usually goes up past 200, when it’s about 125 in reality
In the gym I’ll be on the treadmill with my hands on the pulse monitor and sometimes it’ll go WAY up to eleventy. At the time I’m not particularly exerting myself, ‘blowing’, or feeling ill. Usually I just grip the sensor a little tighter and the reading comes back down to normal. I put it down to a bad connection caused by sweat or just the sensor being full of gremlins.
Sometimes the monitors at work “split” or “double” heart rates. If we are not certain, we check the pulse manually or by stethoscope. Also, does the monitor have a battery? Maybe the battery is getting old.
Some good ideas here. I don’t know that it would be because the contacts got too wet, they’re supposed to be wet, you should moisten them before putting the strap on and after that sweating takes care of the rest. Could be the battery. Could also be power lines, but then why has this never happened before? I was riding a standard route. It may have been getting loose I suppose though it felt tight enough, I’ll see if it happens again.