Garmin Premium Heart Rate Monitor (Soft Strap)

I love my Garmin 310XT... or at least I did. but you see lately we havent really been seeing eye to eye.

OK, maybe im being a bit hasty, after all the 310XT isnt really the problem, its the 'Premium Heart Rate Monitor' that came with it. Its the soft strap one that promisies more comfort than ever before, and is optimized for use in congested areas. I havent tried any other heart monitor straps but i have no complaints about its comfort, actually once im wearing it i forget that I even have it on.

In the begining it was great, all through the tail end of winter I trained with the monitor, Infact using my heart rate as a guide to my effort level became a cornerstone of my whole training regime, and it certainly gave me great results.

But, over the last two months Ive been facing a growing problem. Either ive developed a serious heart condition, or my heart rate monitor is giving me false readings.

It started out with a few spikes right at the end of a 20km tempo run. My HR should probably sit around 160-165bpm at the end of one of these, i have an age calculated HR max of 180bpm but i had a couple of short spikes that went up as high as 194bpm. At the time i just ruled them out as a short glitch... id seen somethimg similar in my vienna marathon and wasnt really worried.

The next run out i saw a small spike right at the start followed by a couple in the middle of a 10k tempo run. It was probably the next run that drew my attention to the problem. It was a slow easy run of 15km at a pace that should see my HR sitting between 120 and 130 but it too had these spikes in the middle, but it was also reporting a fluctuating HR between 120 and 160 for most of the run.

I decided to pay closer attention on the next run, but as murphys law dictates the next run saw just one tiny spike at 10 mins and the rest of the run the HR hardly fluctuated at all, it was pretty much what you expect a HR trace to look like. The next couple of runs were similarly ok.

But then it went wrong in a big way, a longer 27km jaunt and after the first 6-7km it was all over the place the highest spike hitting 220 bpm.... I could go on with each run, but suffice it to say that over the last 5 weeks the accuracy and stability of the HR monitor trace has degraded to such a point that now i am lucky if i get a single correct reading.

Being the guy i am i searched on the internet for possible causes, and the appropriate remedies. First off i started with Garmins Support FAQ.

Frage:  My device is reporting erratic heart rate data. How do I fix this?

Antwort:

There can be various causes for the erratic data. Try one or more of the following solutions to resolve this issue. Make sure the heart rate monitor is snug against your body. Warm up for 5–10 minutes. Reapply moisture to the sensors. Use water, saliva, or electrode gel. Clean the sensors. Dirt and sweat residue on the sensor can interfere with heart rate signals. Synthetic fabrics that rub or flap against the heart rate monitor can create static electricity that interferes with heart rate signals. Wear a cotton shirt or wet your shirt if suitable for your activity. Position the heart rate monitor on your back instead of your chest. Strong electromagnetic fields and some 2.4 GHz wireless sensors can interfere with your heart rate monitor. Sources of interference may include very high voltage power lines, electric motors, microwave ovens, 2.4 GHz cordless phones, and wireless LAN access points. After you move away from the source of interference, your heart rate data should return to normal.

Zuletzt geändert am:  09/28/2007

I was aware that static can cause issues, and that was what i had attributed the initial small spikes to when the problem first started, but im running in the same tops that 2 months ago gave a stabile reading. Ive tried wrapping the plastic unit in cotton to no avail, Ive even run shirtless with the same inaccurate readings.

Another prime cause seems to be poor contact with the skin, Ive tried wetting my skin, wetting the contact pads, wetting the whole strap, and ive even tried using some electrode contact gel, with no reliable improvement.

Ive tried changing the positiononing... ive tried the strap lower, higher, more to the left, more to the right, and even worn it on my back...and you guessed it, with no improvement. Ive tried it tighter, and looser... Ive tried it running in the middle of a field on my own with no phone. Ive tried everything that garmin suggests, and a few things that i picked up on their forums

So all thats left for me to conclude is that either i do have a heart condition, or the strap is malfunctioning and giving me false readings.

So theres nothing for it but to try and get a replacement. Now my garmin is still under guarantee, but, I guess trying to get this sorted will be food for another post. Wish me luck.