HR increases

Now I've got a powermeter and Im comparing my files with my mates I can see a big difference in his HR response compared to mine. if he does a constant power turbo session for an hour, at about 85% of FTP, and I do the same, his HR is absolutely flat whereas mine gradually and constantly rises. why is that? Has it got anything to do with the fact that he is very very fit and I'm just average kinda fit?

 

Maybe.
Particularly with indoor training, HR response can be misleading. FWIW, one would expect to see a certain amount of upward HR movement over time for a constant power - the term is cardiac drift.

I'm something of a heretic on this forum in that I believe monitoring HR has its uses. But one of those uses is not comparing fitness between different individuals.

 

http://www.ultrafit.com/newsletter/november07.html#AA

This article (by Joe Friel) talks about using cardiac drift as a measure of aerobic fitness (paragraph 10). Your buddy is simply more fit than you are. It gives you a goal for which to aim.

 

It's also possible that he has a better fan, a cooler workout room, or drinks more during his workouts than you do.

Do you have his power file, or just his HR data? Silly question, but he's not pacing by speed or HR, right?

 

I dunno about him but I'm very well cooled and drink loads. I saw his power file and his power is completely flat for an hour. his HR settles down afta 5 mins and then stays dead steady (give or take random fluctuation up or down 1 or 2 bpm) for the next 55mins. He has no cardiac drift at all, whereas mine rises anything between 13-15bpm over an hour. We both working at about the same %FTP too.

Thanks for the link from friel but why are more people not interested in this decoupling stuff if its a good measure of aerobic conditon? peterpen and frenchyge seem ready to dismiss the difference between me and my mates HRs as irrelevant or down to the unreliability of HR data - and yet friel sees it as an important indicator. Is it an important indicator or not. I thort I read somewhere else that some of friel's stuff is wrong. is this one of the wrong bits?

Also, if my mate has no cardiac drift, friel says he's maxed out on aerobic improvement at that intensity - is he wasting his time doing steady sessions at that power then?

 

FWIW, I'm not dismissing any potential relevance as much as pointing out that there are many things that can influence HR, especially indoors. I think I'd try to eliminate as many of them as possible before using cardiac drift to evaluate my workout plan.

The last thing I'd suggest you look at is cadence between the 2 files. On a trainer, I can pretty much make my HR do what I want just by changing gearing/cadence.

 

Friel's advice when it comes to power ... is .... what's a polite term? Rubbish?

Re HR drift, are you SURE you're working at the same % of FTP? When working in the 0.85 to 1.00 IF range as I tend to indoors, I saw no discernible change in HR vs. time pattern over five years of progressive training. By Friel's standards, I'm still "under-developed"

Anyhow, thinking/wondering about and/or chasing Power/HR ratio's is honestly just a waste of time IMHO. Focus on CTL and sustainable power for durations pertinent to your chosen events.

 

How do you know that you're not still under-developed, rmur17? What's your measure of being 'fully developed' aerobically?

And yes, I'm SURE we're working at th same % of FTP. Why are all you guys asking me if the conditions were the REALLY the same and then telling me it's completely uninteresting and irrelevant anyway? You obviously think that if conditions were exactly replicated for me and my buddy, then what are HR did wouldn't be so diffrent. if you think that, then why? whats the physiology behind it? Seems to me that somehow my body is demanding more and more oxygen in order to sustain the power output as time goes on - whereas he has a kind of endurance to just sustain the same power with no deterioration in his oxygen usage over time. If you disagree that this must be the case, why do you disagree?

Yeah, I'm doing the CTL and sustainable power stuff, but i dont see why that should make me uncurious about completely different HR responses in different individuals.

 

Maybe...just maybe your buddy has estimated his FTP wrong? If the estimate is correct then would this Friel theory mean that this is it for him at 85% FTP power...no more improvement here.

Isn't it kind of good the longer you are "under developed" at certain power range training?

 

well in a nutshell when some of the "old hands" here like me see a new poster come onboard, from past experience we tend to be skeptical. So until you're a known quantity that will tend to happen. Nothing personal.

Re the rest of the questions: I like many others have been reading and posting online for years and it's quite hard to summarize what's been absorbed over that time. again, I don't know you or how much time you've put into personal research on the topic. From everything I've read and 3-4 yrs of monitoring power and HR, my conclusion is that it's honestly just a waste of time to even bother with it. It simply varies for too many reasons unrelated to *true* load which is power. Google some of Charles Howe's postings on the Wattage list.

My own personal development: well I'm nearly 45 and at a steady 85kg have increased FTP from a solid/well-trained level of 325W in late 2002 to 400W last year (peak of 410W for about 2 weeks). I've trained on and off since '88 and quite consistently for 5-yrs. No way do I have much more under the hood.

given that background, I honestly have found so little consistency with HR --- even to estimate TSS from avg.HR on my non-PM mountain bike ride, that I decided to ditch the strap some time ago. I can estimate ride TSS +/- 10 pts from RPE and duration ... HR is just 'noise' on top of that.

Summary: sorry if I was a bit short. I never intend to attack or put down anyone here and am, admittedly in a brief manner, just trying to save folks time and simplify things. Of course time is indeed yours to spend as you see fit.

 

I see. Maybe this forum is not the place for me then. Maybe one last ditch attempt to learn something:

Ok, I'll look up Charles Howe sometime. I understand that HR varies for external factors and is only a measure of cardio response, not training load, but my question is why is my mates cardio response under the same relative training load so different? This isn't a one-off effect, its systematic and repeatable.......... I'm still a bit mystified, given all the apparent knowledge on here, that nobody knows or cares about this massively different physiological response in two individuals. I know that all tht counts for performance is the power output but I'm just interested. It seems I'm in aminority of 1.

Congratulations. Can I be nosey and ask whether you win races with that kind of FTP? What would your HR generally do over an hour at 85%FTP?

I'm not asking so I can plan my training by HR, or so I can work out how to train. I don't want to use HR to predict my TSS. I've got a powermeter, I can do my stuff with TSS and CTL. I'm asking because I'd like to understand what is happening and why peoples cardio responses are so different.

indeed it is.

 

That's a good question, and judging by the responses and (more importantly) lack of responses that you've gotten so far, I'd guess that's a question that most of the posters here have not heard before. So, from our perspective, it could quite possibly be a one-off effect, and I don't think we're being dismissive or condescending to ask that in your analysis of the power and HR files you've controlled for the quite commonly seen variations that would definitely cause this phenomenon (namely hydration levels, cooling, cadence, improperly guess-timated FTP, power measuring methods used, type of trainer, etc.).

I don't see that you've responded to my last post asking about the cadences used. Let's assume that someone here is interested in what you're seeing and wants to take the time to help you figure it out. Instead of insulting you further with all the questioning, shall we cut to the chase and see if you're willing to post the 2 (or more) power files in question so that we can actually look at the data and see if we can find the cause that you're looking for? You can either zip and attach the files to a post, or take a screen shot of the power/hr/cadence/speed graph, save it to a jpg file, post it to tinypic.com and post the links here.

Personally, without seeing the data in question, I'm plum out of ideas. It's an interesting puzzle ('puzzle' because, like rmur17, it's unlike anything that I've seen, which also, like rmur17, gives me skepticism about Friel's analysis) but based on your reaction to previous inquiries for more information, not one that I'd be interesting in diving into without being given the 'whole picture.'

You can always nose around on some of the other threads. http://www.cyclingforums.com/showpost.php?p=3649065&postcount=41 (see item #8)

 

Daniel,
I've watched this thread and am interested like you to hear more. When I read Friel's piece about HR drift ratio as a metric for fitness I posted questions here and elsewhere and tried to find some supporting science for that concept. I came up dry on various forums, google searches and PubMed searches. Maybe my search terms were poorly chosen but I can't find any studies that conclude that you can measure fitness by cardiac drift ratio as he suggests. Like Rick and frenchyge my power files show nearly the same cardiac drift at the beginning of a training year as they do throughout the year and haven't changed much over the last year and a half when I've had access to both HR and power data. I've actually started wearing the HR strap again to collect more data to see if he's onto something here.

I also notice in Friel's article that he specifies that this cardiac drift ratio measurement should be made at Aet or roughly 65% of your 30 minute MMP. I don't do a lot of steady rides in that range and I suspect the other folks here who base their training on SST and L4 don't either.

There's a lot of published work on cardiac drift during exercise as a function of hydration state and cooling which is probably why folks questioned you on those points. But I haven't been able to find any studies that relate cardiac drift to overall fitness. I still hope some of the exercise physiology folks can shed some light on this but lack of responses so far and coming up dry on searches makes me skeptical.

Even when I was fully in the Jannsen camp and really believed in things like Conconi tests I was really hesitant to use HR to compare between different athletes. Maybe this drift ratio allows that sort of comparison, but again I'm skeptical. There are just so many differences in terms of heart stroke volume, body mass, hydration state, cooling efficiencies and other hard to measure factors that make it hard to make comparisons between different folks.

Anyway, no answers here, but I'm also interested in what folks have to say and I'm sure not knocking your question.

-Dave

 

I have to admit i start 'seeing red' when I read Friel's stuff. He's *way* behind the curve and even his latest 'breakthrough' is still well behind it. I can't put any credence to anything he says.

We have PM these days ... and most folks have some personal anchor point for sustainable power between 20min and 60-min that they're happy with calling threshold power. Regular training and/or testing and/or racing tells us pretty much all year round where we are in FTP terms. If one choses to use PMC then CTL tells us where we are in overall training load terms. One can go more detailed if necessary ...

Now throw the term "fully aerobically developed" in there. And throw a widely shown and acknowledged imprecise measure of HR into the mix in terms of definining it. And specify that you need to ride for weeks/months on end of basic L2 training before you can even measure whether you're aerobically developed or not ....

Arghhh ... it's such a pile of old dog-poo that I can't even start to make a list of why it's so!!

HR (and cadence of course) are just big ole slippery neon red herring. Chasing 'em is just too much time and waste of energy for me (I AM old and cranky of course ).

Just to throw one bone for a flatter than normal HR response: simple acute training load. I know consistently that when I'm pushing it that my HR curve is flatter than normal. Now for the bad news: what in god's creation use is that in terms of defining/denoting/demarking/quantifying "aerobic development"?? I know I'm pushing it simply by how my legs and overall body feels. CTL/ATL/TSB help confirm it. Take an extra rest day or two and suddenly I'm feeling like "me" again. Did my "aerobic development" change appreciably in such a short time?

Anyhow, i strongly feel that we have much^3 better tools at our disposal than one might by adhering to anything Friel has to say about power training.

Sorry for the rant.

 

Because there's really no evidence that it is.

 

While I can't think of any studies off-hand, in a general sense you would expect that greater cardiovascular fitness would be associated with an attenuation of cardiac drift. The big leap-of-faith, though, is in claiming that attenuation of cardiac drift to X degree under Y conditions represents some sort of benchmark that you can use to assess when your "aerobic development" is "complete". That I just can't see....

In any case, the SRM software has for years included a far more sophisticated tool for graphically assessing cardiovascular fitness/cardiac drift, but while I find the basis for it easy to understand and logical, dang if I've ever found any real use for it!

 

Good point! To add to it: a few years ago I had a ~6 mo streak during which I rode at least 4 h on one weekend day. My heart rate response to exercise was clearly suppressed, i.e., at a given submaximal power my heart rate was lower than usual, and it didn't increase as quickly at the onset of a workout. I don't know about the more long-term drift, though...guess I should go back and take a look. In any case, however, what's relevant here is that my ability to generate power for various durations (including during such long rides) wasn't any better than when I'm not doing such mega-miles (well, for me, anyway), even though the latter impacts my heart rate. I'd therefore hypothesize that an excessively "flattened" heart rate response may actually be a bad thing, as it may be a sign of longer-term overreaching/overtraining (of the parasympathetic variety).

 

I know very little about exercise physiology and I could never figure out what to do with that feature in the SRM software either. It is in some way comforting to hear someone like you saying the same thing, Andy.

 

Thank you for some really good responses. Frenchyge, sorry for not answering about cadence, we both always use the same cadence too (about 91-93rpm).

Maybe friel was a red-herring in this thread altogether - I'm not really bothered about quantifying anything, but if people dismiss him I kinda would like to know why and youve explained that now.

I suppose I'm just interested in what causes cardiac drift, given that my mate doesn't have any and I do. I'll leave you all in peace now and go and look elsewhere. Thanks.

 

That's good...I guess?

Seriously, the real problem is that the analysis can only be applied to individual files, which simply don't provide enough data to overcome the variability in the heart rate-power relationship, at least when cycling outdoors. It would be more useful if you could fit the regression to all the data from a batch of files simultaneously, or if you could just keep track of the slope, intercept, PWC150, 'shifting', from individual files in a database (e.g., in the SRM software's equivalent to WKO+'s Calendar View). The latter could be accomplished by entering the derived values into, e.g., a spreadsheet, but I've never gone to the trouble because I don't think I'd learn anything of value.