heart rate peaks - me or my monitor? (Read 765 times)

Hi all after reading various posts and logs I've come to the conclusion that I am running my training runs a bit too fast, so I've taken up my trusty (or so I thought) HRM - a Polar RS 400. So, I'm tooling along at about 140, and then after an hour with no pace change or alteration in my perception of effort it gives a read-out of 163; same thing about 10 minutes later, 171. I've done short runs at those rates, and there's no way that it felt the same. So, is it me, or the monitor? If it's me, should I be concerned? On the upside, I ran that route about a minute faster at less than 140 than I did 6 months ago (when I couldn't actually stay below 140). I hate it, but it works! All help and advice very gratefully received.

I've been using a HR monitor for three years, and the only time I've had true dramatic, short-term spikes were: a) when I was almost hit by a car; and b) when I ran past an old girlfriend who I really didn't want to recognize me. Short of these life threatening instances (and both of my examples qualify ), your heart rate just doesn't jump around wildly. Did the HR reading return to something more logical shortly after it spiked? If so, then its far more likely that there was some kind electrical interference with the signal between the strap and the watch.

thanks for the tips - heart rate did climb a little over the course of the run, but I slowed pace to compensate, and monitor did drop back pretty quickly to a 'normal' level - so I think that berner's point is probably right although I will also try the 6 sec check. This only ever happens on runs that are heading up towards the 1 1/2- 2 hour mark.

Sounds like HR creep as others have stated. A malfunctioning monitor strap would generate spikes and generally erratic readings often >>200 bpm. Plotting out your HR from the exercise file would likely provide the answer. Note that I have a RS800, with a WearLink strap, and have to make sure that (1) the contacts on the strap are wet enough (place under tap). (2) the contacts on the strap have been cleaned thoroughly (wash with liquid soap by hand). The latter caused a week of very strange HR readings.

I believe electric fences / home security/ wifi? causes problems too.

Electric fences and invisible fences for sure. I doubt that wifi signals are strong enough. I've also had signal problems running by power transformers and under electrified train tracks (the L in Chicago).

yeah, it's what havanarnr describes oh so much better than I did - a sudden spike then a rapid return to round about the regular heart rate. I'm trying to run at around 140 on easy runs, so really don't want to end a run around 171 for those purposes. Sorry for confusing folks by my bad explanation. So it seems that they just spike for no particular reason from time to time? That's very handy to know, and thanks d

My polar spikes by an army depot. It really has not spiked since I moved away from that depot. People spikes last a few seconds, mechanical spikes usually last less than a second. If I have a spike last a really long time, like a minute, i change the battery in my watch. Fixes the problem every time.

One other cause of spikes (especially long term >30s spikes) is weight loss! I have lost about 20 pounds and never adjusted the strap. After I tightened it up, the spikes went away.