HR - can somebody please please please explain...

TheGreatGatsby

..this to me. I'm just not getting it and I don't understand how its meant to work.

Right, today is the day after my rest day so am fully refreshed and I always do a 3.5hr+ ride. Usually my HR is up around 120-137bpm and rises on climbs and efforts. With winds and other weather factors its usually give or take 10bpm. Last week did a 3hr 45ride, 66miles and burnt over 2000 cals - yay me!

Today weather was rubbish. Very cold very windy and very wet. I did 3hr 50 ride, 69.5miles, av speed of 18.9 but only burnt 1540 cals. My HR was WAAAAAAYYY below normal like 87-110 with a peak of 143 up a hill in top gear into the wind. So what the hell is going on??

Does weather and barometic(?) pressure have an effect on HR? I would have thought it should be higher especially considering I was going really well despite the wind.

Can somebody please explain the factors that may cause a serious low HR when perfomance isnt affected?

Gats

method

It could be your HRM giving dodgy readings, but other factors effect heartrate, if you're tired, ill etc. I sometimes find I can't get my heartrate up to its usual rate and yet I feel fine, when this happens its best to go on feeling and ignore the HRM. Also in this instance I'd ignore the calories burnt.

Jeff Jones

As Method says, ignore the calories burned readings from your HRM. They're very bad estimates of what you're actually burning. So bad that you could get a better idea by multiplying 700 (guesstimate based on a power output of a bit under 200W) by 3.8 (number of hours ridden), which is about 2600.

Your low heart rate could be a function of the weather, how much you've eaten, how tired and how fit you are. If you're going quicker, then it doesn't really matter.

nmcgann

Jeff Jones wrote:

As Method says, ignore the calories burned readings from your HRM. They're very bad estimates of what you're actually burning. So bad that you could get a better idea by multiplying 700 (guesstimate based on a power output of a bit under 200W) by 3.8 (number of hours ridden), which is about 2600.

Your low heart rate could be a function of the weather, how much you've eaten, how tired and how fit you are. If you're going quicker, then it doesn't really matter.

Actually, I find that if my HR is "usual" for the effort I'm doing then my Polar is pretty close to reality - I have a powertap now and can compare real work done in kj with kcal shown by the polar and they are close (the polar slightly under-reads).

You are right though re all the things that can affect HR - I know that if I can't get my HR up to normal levels and I'm not ill, I haven't eaten/drunk enough for the ride I'm trying to do.

Neil

e999sam

I’ve found that there is not any correlation between perceived effort and heart rate. I’ve found that if I’m fit and am well rested I can easily get to my MHR. If I’m fit but tired from previous rides or feeling unwell it doesn’t matter how hard I try I can’t get to anything like my MHR.

ut_och_cykla

How was your average speed the first ride - similar to second (with allowance for weather conditions)- in which case either you are phenomally fit or your HRM is playing up (and thereby wrongly calculating teh already unreliable calorie use. If your average speed was down too then you are sickening, grossly underfed or overtrained. My guess would be the second.

Did you eat on the 3.5 hours you were out? No? Naughty! No carbs to burn means slower cycling. Starving and training hard/long is not a good idea. But hen you know that don't you Gats :?
Rest and eat, try another HRM.

Jeff Jones

nmcgann wrote:

Actually, I find that if my HR is "usual" for the effort I'm doing then my Polar is pretty close to reality - I have a powertap now and can compare real work done in kj with kcal shown by the polar and they are close (the polar slightly under-reads).l

Lucky you then :-)

I've found that both my recently deceased Polar 725 and my Garmin Edge really overestimate calories compared to an Ergomo, which should be fairly accurate. The Polar is better than the Garmin, but always too high.

Not that it really bothers me because I'm not trying to lose weight, but it's interesting to see the discrepancy.

phil s

Calorie consumption on a Polar is estimated by heart rate readings. Given it was cold you probably used more calories than you thought. I raced yesterday in the worst conditions imaginable and my race started with heart rate as high as you'd expect for a fast ride, then going higher when I went on the attack and did a solo bridging effort. However, I got brought back after 20mins and by then I was soaked through and freezing (yes, I rocked up for a 130km race in the cold and wet with woefully inadequate clothing). Coupled with the cold, I couldn't bring myself to eat because I could no longer feel my hands and unwrapping an energy bar was beyond me. The next thing I noticed was that my heart rate was plummeting (86bpm at one point) and I was starting to feel cold through my body that was so deep I decided to pack immediately. Lesson learned - on cold days dress up and never neglect eating. Forget these things and it's a short cut to sub-par performance.

FSR_XC

Had an interesting reading from my HR monitor a few weeks ago.

Apparently my max HR on the ride was 222bpm.

e999sam

I get a spurious reading now and again. I’ve seen 230+ recorded as my maximum when it’s actually around 180.

TheGreatGatsby

ut_och_cykla wrote:

How was your average speed the first ride - similar to second (with allowance for weather conditions)- in which case either you are phenomally fit or your HRM is playing up (and thereby wrongly calculating teh already unreliable calorie use. If your average speed was down too then you are sickening, grossly underfed or overtrained. My guess would be the second.

Did you eat on the 3.5 hours you were out? No? Naughty! No carbs to burn means slower cycling. Starving and training hard/long is not a good idea. But hen you know that don't you Gats :?
Rest and eat, try another HRM.

On the both rides average speed was about 17/18 miles an hour which is what I don't get. Surely if I was not rested, sick or underfed the results would show in the average speed? But considering they were roughly the same for the same length journey I don't get why my HR was down in my shoes!

No of course I didn't eat on the rise! 3.5 hours doesn't warrant eating on! Went out at 4.45am so no breakfast as per usual - same as the week before just a pint or so of water and away we go! I never eat on a ride of less than 5 hours. theres no point as the calories/fat you put in negates the ones you burn wheres the point in that!?

Maybe the HRM was being wonky? did my 43m commute today and that was hard but my HR was back up to where it should be for oth legs of the journey - average speed of 18 in both directions. which is lower than friday which was 19 to work 21 on the way home.

I just don't get it.

Gats

Mike Willcox

TheGreatGatsby wrote:

ut_och_cykla wrote:

How was your average speed the first ride - similar to second (with allowance for weather conditions)- in which case either you are phenomally fit or your HRM is playing up (and thereby wrongly calculating teh already unreliable calorie use. If your average speed was down too then you are sickening, grossly underfed or overtrained. My guess would be the second.

Did you eat on the 3.5 hours you were out? No? Naughty! No carbs to burn means slower cycling. Starving and training hard/long is not a good idea. But hen you know that don't you Gats :?
Rest and eat, try another HRM.

On the both rides average speed was about 17/18 miles an hour which is what I don't get. Surely if I was not rested, sick or underfed the results would show in the average speed? But considering they were roughly the same for the same length journey I don't get why my HR was down in my shoes!

No of course I didn't eat on the rise! 3.5 hours doesn't warrant eating on! Went out at 4.45am so no breakfast as per usual - same as the week before just a pint or so of water and away we go! I never eat on a ride of less than 5 hours. theres no point as the calories/fat you put in negates the ones you burn wheres the point in that!?
Maybe the HRM was being wonky? did my 43m commute today and that was hard but my HR was back up to where it should be for oth legs of the journey - average speed of 18 in both directions. which is lower than friday which was 19 to work 21 on the way home.

I just don't get it.

Gats

If you are for real then you are incredibly stupid. On the other hand nobody can be that stupid so you aren't for real.

Why don't you just go away?

steve arnold

Not eating before a ride of such duration especially first thing IMHO will surely lead in the current jargon to a sub-optimal performance. As I understand it you burn up stored carbs first then what you,ve eaten prior to effort. If riding on empty stomach no re-supply in the pipeline so surely cruising for a bruising bonk wise. If you follow your strategy all the time wont you waste away to nothing? Everything I,ve come across advise wise seems to indicate regular top ups will enable effort to be maintained longer and reduce recovery times. Would you perhaps be better [ not trying to be an amateur trick cyclist] to examine your attitude to food as doesn,t seem quite normal to me to want to avoid replacing spent fuel on a regular basis. Myself not a very experienced cyclist averaging about 14mph over mixed flat/hilly over 3 hours but do find helpfull to eat small carbo snacks after every hours riding. What do you hope to achieve by not eating for up to 5 hours with no breakfast even ? Does not seem a wise move to me . If talking complete ballcocks not offended in the least if somebody puts me right.

ut_och_cykla

I believe GAts is for real but he has had what could ploitely be called 'eating issues' adn clearly still obsesses about calories in and out depsite the fact I think he said he was below 10 % body fat.
He wonders whetherhis HRM is wonky - it may well be and the cold might well have affected the HRM and his heart's performance but something else is a bit wonky too - its rude and blunt but I think Gtas is a little bit nuts. :oops:

phil s

Not eating before or during a 3.5hr ride is stupid. As others have said - grow up!

Jeff Jones

Coming back to what I wrote earlier, calories burned relates closely to power output. You burn more calories per km and per minute riding at higher power outputs - as well as getting fitter.

Now, riding harder burns more carbohydrate in proportion to fat, so it's important to fuel yourself to maintain that level of effort. If you don't eat, you limit how hard you can go because you will run out of glycogen too fast. I don't have numbers to support this but if in addition to a decent breakfast I eat, say, 400 cal on a five hour ride, I will likely burn more than that simply because I can ride faster compared to if I didn't eat. Also, I won't be as ravenous afterwards - which is quite important.

This has been brought up before: Not eating before and during riding just puts you in starvation mode and teaches your body to hold onto its reserves, which is the opposite of what you're trying to achieve.