Strange HRM readings

A few months back I purchased a Polar S510 but I seem to think that the results I get are too
high. I am 29, not the fittest around but when running if I try stay within the zones the pace
seems to slow for
me. I find a comfortable pace has my heart around 170. Then this morning while cycling through a
pretty tough section it said my max heart rate was 228!

I am pretty new to this but it just doesn't seem right to me. Does anyone have any thoughts on what
going on here. Could this be due to interference, or does that simply result in no readings. Any
help appreciated.

 

Andy wrote:
> A few months back I purchased a Polar S510 but I seem to think that the results I get are too
> high. I am 29, not the fittest around but when running if I try stay within the zones the pace
> seems to slow for
> me. I find a comfortable pace has my heart around 170. Then this morning while cycling through a
> pretty tough section it said my max heart rate was 228!
>
> I am pretty new to this but it just doesn't seem right to me. Does anyone have any thoughts on
> what going on here. Could this be due to interference, or does that simply result in no readings.
> Any help appreciated.

The 228 is caused by outside interference. It's a real pain in the arse, screws up the averages for
your session. See if it happens at the same spot next time your are going past, you may have to
change your route to avoid it. Not much else you can do. I think they arrived at the 228 figure
based on the standard MAX HR = 228 - age , so in simple terms nobody is expected to have a max HR
greater than 228 .. of course this is a generalisation.

The worst blackspot for me is the Sydney Harbour Bridge .. the train lines run next to the bike
lane and the interference from the power lines overrides the HRM. Maybe I should line my helmet
with aluminium foil to prevent the transmissions affecting my brain, but then how would the UFO's
contact me?

Another thing to keep in mind is cardiac drift .. as you dehydrate your HR will increase. A better
explanation from (http://www.active.com/story.cfm?story_id=8082)

" This phenomenon, called cardiac drift, occurs because dehydration causes a drop in blood volume,
which means less blood is pumped with each heartbeat. A study published in the Journal of Applied
Physiology found that heart rate increases seven beats per minute for each 1 percent loss in body
weight due to dehydration.

Cycling for one hour in 70-degree heat can result in a loss of 1.5 to 3 pounds. That's a 1
percent to 2 percent weight loss for a 150-pound cyclist, which would increase heart rate by
seven to 14 bpm.

If this cyclist is planning a tempo ride at a heart rate of 150 to 155 bpm, she should account for
the fact that her pace will slow during the ride, and allow her heart rate to increase to about 160
to 175 bpm by the end. "

 

Andy, same probs as you - heart rate jumps to 220+ - it's power line intereference or something like that

 

"Andy" <[email protected]> wrote in message news[email protected]...
> A few months back I purchased a Polar S510 but I seem to think that the results I get are too
> high. I am 29, not the fittest around but when running if I try stay within the zones the pace
> seems to slow for
> me. I find a comfortable pace has my heart around 170. Then this morning while cycling through a
> pretty tough section it said my max heart rate was 228!
>

You will get "crazy " readings when passing under powerlines. I also used to get high readings and
170 felt comfortable while running. My max heart rate for my age was also well over what was
predicted by some of the formulas in the books etc. (found by running as hard as I could uphill) I
have come to the conclusion that some people just have a faster heart. Most of my siblings also have
a fast heartrate. My wife, in contrast is quite unfit, yet has a very slow heartrate.

 

Luther Blissett ... wrote

> ... I think they arrived at the 228 figure based on the standard MAX HR = 228 - age ,

The idea that 220 minus your age indicates your maximum heart rate is little more than an urban
myth. To discover where this over-simplification arose, see this New York Times interview with one
of the guys who proposed the idea in the first place.

http://www.athletictrainingservices.com/MHR.htm

 

Andy <[email protected]> wrote in message news:<[email protected]>...
> A few months back I purchased a Polar S510 but I seem to think that the results I get are too
> high. I am 29, not the fittest around but when running if I try stay within the zones the pace
> seems to slow for
> me. I find a comfortable pace has my heart around 170. Then this morning while cycling through a
> pretty tough section it said my max heart rate was 228!
>
> I am pretty new to this but it just doesn't seem right to me. Does anyone have any thoughts on
> what going on here. Could this be due to interference, or does that simply result in no readings.
> Any help appreciated.

I often get funny readings like that if I don't have enough sweat to make a good electrical contact
with the chest band. Once I warm up a bit and start to sweat a bit it all works ok. Try warming up
until you get a steady reading and then do your normal exercise.

 

Keith wrote:
> Luther Blissett ... wrote
>
>
>>... I think they arrived at the 228 figure based on the standard MAX HR = 228 - age ,
>
>
> The idea that 220 minus your age indicates your maximum heart rate is little more than an urban
> myth. To discover where this over-simplification arose, see this New York Times interview with one
> of the guys who proposed the idea in the first place.
>
> http://www.athletictrainingservices.com/MHR.htm

I'm well aware of the limitations of the formula (and I notice I got it wrong!), I was merely
engaging in a bit of late-night speculation as to why the HRM displays 228 when it gets
interference, and not say, 999 or 255 or plain old 0.

Cheers - LB

 

"Marty" <[email protected]> wrote in message news:[email protected]...
> I often get funny readings like that if I don't have enough sweat to make a good electrical
> contact with the chest band. Once I warm up a bit and start to sweat a bit it all works ok. Try
> warming up until you get a steady reading and then do your normal exercise.

You are supposed to wet the strap before starting. I give mine a quick squirt under a tap (or
bottle) and rub water on my chest too. I'd much rather have a good connection and accurate data than
waste 1hr+ of battery time. Trams in Melbourne give my Polar hell, but not for too long and it's
easy to fix most hiccups with the software.

hip

 

"Luther Blissett" <[email protected]> wrote in message
news:[email protected]...
> Keith wrote:
> > Luther Blissett ... wrote
> >
> >
> >>... I think they arrived at the 228 figure based on the standard MAX HR = 228 - age ,
> >
> >
> > The idea that 220 minus your age indicates your maximum heart rate is little more than an urban
> > myth. To discover where this over-simplification arose, see this New York Times interview with
> > one of the guys who proposed the idea in the first place.
> >
> > http://www.athletictrainingservices.com/MHR.htm
>
>
> I'm well aware of the limitations of the formula (and I notice I got it wrong!), I was merely
> engaging in a bit of late-night speculation as to why the HRM displays 228 when it gets
> interference, and not say, 999 or 255 or plain old 0.
>

under power lines you could get plus 50 or plus 100 where the counter inside the monitor is
responding to the Mains frequency of 50 cycles per second. ie counting the pulses of the power line
as well as your own pulse. This would correspond to a pulse of 178 or 128. but this would be
complicated when your heartbeat was in sync with the 50 Hz.power pulse in which case only one count
would register and the reading would be less than the combined amount.

 

Keith wrote:
> Luther Blissett ... wrote
>
>> ... I think they arrived at the 228 figure based on the standard MAX HR = 228 - age ,
>
> The idea that 220 minus your age indicates your maximum heart rate is little more than an urban
> myth. To discover where this over-simplification arose, see this New York Times interview with one
> of the guys who proposed the idea in the first place.
>
> http://www.athletictrainingservices.com/MHR.htm

Then there were some French scientists monitoring the heart rates of the Ferrari drivers during the
1981 season. Didier Pironi was over 200 bpm for almost the entire duration of the Monaco GP, while
the highest reading they get for Gilles Villeneuve was 165, and that while he was flying off the
road backwards in a fourth-gear corner...

<ob_cycling> Rob English once told me he ran somewhere around 210 for a while when closing down a
gap during the 2001 HPV World Championship Road Race. At the time he was, IIRC, 24 </ob_cycling>

Dave Larrington - http://www.legslarry.beerdrinkers.co.uk/
===========================================================
Editor - British Human Power Club Newsletter
http://www.bhpc.org.uk/
===========================================================

 

"hippy" <[email protected]> wrote in message
news:<[email protected]>...
> "Marty" <[email protected]> wrote in message news:[email protected]...
> > I often get funny readings like that if I don't have enough sweat to make a good electrical
> > contact with the chest band. Once I warm up a bit and start to sweat a bit it all works ok. Try
> > warming up until you get a steady reading and then do your normal exercise.
>
> You are supposed to wet the strap before starting. I give mine a quick squirt under a tap (or
> bottle) and rub water on my chest too. I'd much rather have a good connection and accurate data
> than waste 1hr+ of battery time. Trams in Melbourne give my Polar hell, but not for too long and
> it's easy to fix most hiccups with the software.
>
> hip

Water is a very poor conductor of electricty, it needs some kind of salt to make it a proper
electroyte which can conduct electricty.

Marty

 

"Marty" <[email protected]> wrote in message news:[email protected]...
> > You are supposed to wet the strap before starting. I give mine a
quick
> > squirt under a tap (or bottle) and rub water on my chest too. I'd
much
>
> Water is a very poor conductor of electricty, it needs some kind of salt to make it a proper
> electroyte which can conduct electricty.

Hmm. Well it always seems to work for me. Probably all those metals in the water! Oh, hangon.. I
drink that stuff.. :-S

hip

 

I'm no expert on the powerlines issue - I know they cause interference, and so do tramlines, but for me they just usually cut out the signal.

I reckon it goes up too high when it isn't conducting properly - too cold, not enough sweat, air getting between strap and chest, or panting so hard that the strap moves. It happens to me even in the absence of powerlines, but very rarely happens on warm days or when I've warmed up.

But doesn't it give you the shits when you want to know your max, and find it was 228? That's not right...