How Did You Justify the Cost of a Power Meter?

[S-Express]

"Your heart rate is a reasonable readout of the effort you are making". So if you do your intervals at roughly 170 (say), this will make sure you're working hard enough, but not too hard.

I can't see any possible benefit in doing intervals at such a low intensity level - assuming you mean 170bpm. For most young/middle-age adults, 170 is firmly within the low-level endurance zone. I already said - as did others, that HR generally gives a reasonable approximation of steady-state, low level endurance efforts.

"someone else can come along to confirm (or otherwise) that HR and power readings on a ride (where you don't overdo it and bonk) have a pretty good correlation." Thank you 'someone'. @Tin Pot "HR is nothing like power" @S-Express "They don't, or if they do it's coincidence" @400bhp "Power and HR are correlated". I would be interested to see a graphic readout of an interval session (@S-Express ? @400bhp ?) where both power and heart rate are plotted. Please surprise me by showing that there is no correlation between the power and HR. Yes, the HR will lag, but not by much once the rider is warmed up (ie after the first couple of intervals). Is what lag there is such a "massive" detriment (in the context of a 2+ minute interval)?

Again, I'm finding it incredibly difficult to read/decipher/understand what you are saying here, but assuming I've interpreted your typing correctly:

I'm not sure you appreciate the issue of HR lag properly when undertaking high intensity intervals. Yes it lags, but it never catches up either - which is the point you are mistaken on. Which is why you cannot use HR as a reliable guide to interval training.

HR data offers nothing useful or valuable (from a training data pespective) if you already have reliable power data. Temperature, wind direction, fatigue, hydration, fuelling or simply the time of day can all influence HR readings in respect of your performance from one day to the next. Power, on the other hand, remains as power regardless of all the other factors, and in that sense, it is the only metric that you need.

The guy with the highest HR may not win the sprint, but the guy with the highest power output certainly will.

Useful discussion (with some graphs) here: http://bicycles.stackexchange.com/q...tor-have-if-you-have-a-powermeter/42806#42806

 

[Ajax Bay]

Yes it lags, but it never catches up either

What does it never catch up? Catch up with what?

 

[adscrim]

Hi Guys,

Got a massive ride planned for May that's going to take a really large volume of training and want to use power to support me with this especially for the interval sessions I have planned.

I have settled on the power tap P1 pedals as it means I can transfer them between multiple bikes so I can train with power on the turbo as well as on the road.

I had it all ready to go in my shopping basket yesterday, but just couldn't bring myself to hit 'buy' on a £900 purchase!

So my questions are:

• If you have a power meter, how did you justify the cost of it?
• Has it been worthwhile?
• Have you seen the training benefits from it

It's not going to bankrupt me, I can afford it but it's just the principle of paying this much money when I could get a replacement bike for the cost.

Thanks,

Ben

1. I've got single sided Garmin Vector pedals (the 2nd generation) through the cycle to work scheme which means I'll end up paying ca £250 for them. Obviously, the saving and being able to spread that much smaller cost both somewhat negate the need to 'justify' the purchase - for me at least.
2. Yes - I'm a training quitter. I find it much too easy (especially on the turbo) to give in or, in the case of training to HR, justify easing off as there are too many external factor in measuring HR and I really am going as hard as I should be. With power, having measured FTP, I have no wiggle room. If the plan says 5 mins at 95% FTP then that what I do (British Cycling has loads of plans available).
3. Yes - I've notice improvements on regularly ridden climbs and 'Stava segments' since training with power (or perhaps more importantly using the constant nature of power to train more effectively).

Ultimately though, I know I don't need it. My HR will max out around 175. Assuming I'm healthy, if I keep it below 160 I know I can ride all day. But I'm glad I've got it (caveat the reduced price I'm paying for mine).

 

[S-Express]

What does it never catch up? Catch up with what?

Sorry, I assumed it was obvious. It never catches up with and accurately tracks the effort you are making (in terms of high intensity intervals). Therefore, we can deduce that it is not a good or accurate indicator of effort at these levels. This is common knowledge to anyone who has ever ridden HIIT while wearing a HRM.

 

[Ajax Bay]

I suggest it is neither obvious nor common knowledge (whatever 'it' is). How do you know HR doesn't "catch up with and accurately track the effort you are making"? What are you comparing it / tracking it against? Power? If so, then you are actually saying that there is a correlation between HR and power (cf your assertion: "[HR and power readings on a ride. . .] don't [have a pretty good correlation]. If they ever do, it's coincidence, not science." If not, then again what is the rider's HR not 'catching up' with (and how are you measuring that)?

I said "if YOU do your intervals at roughly 170 (say), this will make sure you're working hard enough". Not one of your young coaching charges.
Let me know how you get on with 10 x 2 minutes at 170bpm, by the way. For the aged me (rest 32, max 182) 165 is about right. (NB 173 riding to the top of Hardknott after 170km.)

 

[S-Express]

Sorry mate - you've really excelled yourself this time. I've no idea what any of that actually means. Genuine question - is English your first language?

I suggest it is neither obvious nor common knowledge (whatever 'it' is).

it = your HR v effort and how it (doesn't) track - ie the thing we've been talking about in this thread.

How do you know HR doesn't "catch up with and accurately track the effort you are making"?

By strapping on a HRM and riding intervals. Give it a try. Thousands of others have, and found the same thing. ie common knowledge.

What are you comparing it / tracking it against?

Compared with the effort made ie RPE.

If so, then you are actually saying that there is a correlation between HR and power

We've already covered this.

I said "if YOU do your intervals at roughly 170 (say), this will make sure you're working hard enough". Not one of your young coaching charges.

No idea what you mean, sorry. Can't decipher that at all.

Let me know how you get on with 10 x 2 minutes at 170bpm, by the way.

No idea what you mean here either. Riding for 2 minutes at 170bpm would be a complete waste of time. I don't think anyone ever said different. I think you are the first person to mention this. For me, I generally ride for 2-3hrs at averages generally over 170, so a 2min interval at that level would be bizarre.

For the aged me (rest 32, max 182) 165 is about right.

No idea what you mean. What is this relevant to?

 

[T.M.H.N.E.T]

*tinfoil hat*

 

[jowwy]

don't need to justify anything......want it, can afford it, buy it....its that simple

 

[400bhp]

@400bhp[/USER] "Power and HR are correlated". I would be interested to see a graphic readout of an interval session (@S-Express ? @400bhp ?) where both power and heart rate are plotted.

Here you go fella, I've copied the results of my hour long session last night on a turbo where I had a power meter and heart rate monitor attached. The main aim of the session was 2 x 8 minute intervals at maximum effort:

You can see that power and HR are correlated (as I said) and there is a distinct lag.

I've zoomed in on the last of the 8 minute efforts. The y axis of the graph doesn't help show the difference but the numbers on the left help:

You can see my power was pretty stable over the 8 minutes. It started at 305w an. My HR actually started at 136 bpm. It didn't climb to 160 bpm until 1.5 minutes or so. It topped out at 179, 6.5 minutes in.

Hopefully this helps somewhat.

I could probably download the data and correlate it if I could be arsed.

 

[Ajax Bay]

Thank you very much for taking the trouble to share that, @400bhp Those curves of HR and power are what I'd expect and consistent with what you and I have agreed: "power and HR are correlated". And if one could plot your subjective RPE (@S-Express 's Rate of Perceived Exertion (RPE)) I'd expect it to be similar to your power graph. All 3 are correlated, with HR lagging, and then showing a bit of drift as your core temperature rose (perhaps depending on the effectiveness of your fan).

Good session btw.

 

[S-Express]

Thank you very much for taking the trouble to share that, @400bhp Those curves of HR and power are what I'd expect and consistent with what you and I have agreed: "power and HR are correlated". And if one could plot your subjective RPE (@S-Express 's Rate of Perceived Exertion (RPE)) I'd expect it to be similar to your power graph. All 3 are correlated, with HR lagging, and then showing a bit of drift as your core temperature rose (perhaps depending on the effectiveness of your fan).

Good session btw.

Which kind underpins the point made earlier that HR is not a reliable indicator of effort, especially at higher intensities - which is what people have been saying here all along. Glad we cleared that up. All this seems to pivot around your interpretation of the word 'correlation' - correlation implies a relationship - which they obviously have - but it is not a linear one. If all of this was about you trying to score a pedantic point, why didn't you just say so in the first place?

The 'drift' is not because of core temperature rises, btw.

 

[Ajax Bay]

HR is not a reliable indicator of effort, especially at higher intensities

Do not agree and suggest that the graph @400bhp shared show that HR IS a reliable indicator of effort, used with the understanding that there will be a lag between effort and HR increase, as you'd intuitively expect. In the absence of (significant expenditure on) a power meter, HR is probably a better communication metric for coaches to use than RPE. people like numbers as opposed to (their) subjective judgement of effort.

this seems to pivot around your interpretation of the word 'correlation' - correlation implies a relationship - which they obviously have - but it is not a linear one.

Thank you. Your confusion seems to pivot around your interpretation of the word 'correlation'. Well spotted that it is not linear - who suggested it was? Increase power, HR will increase rapidly; maintain power, HR will be maintained drifting slowly up (rate of drift depends on effort compared to threshold); drop power, HR drops (the faster the fitter the rider is). Correlation.

 

[S-Express]

FFS, this is going nowhere.

Do not agree and suggest that the graph @400bhp shared show that HR IS a reliable indicator of effort,

First you say it is a reliable indicator of effort.....

used with the understanding that there will be a lag between effort and HR increase

.....and then you say it isn't. You can't have it both ways. The lag is the thing that makes it an unreliable indicator of effort, as you yourself have just indicated. 400bhp even said himself there was a distinct lag and the graph even shows it. Either way, one graph is hardly conclusive. He could do the same session again tonight, or tomorrow and come up with a completely different HR track, even if the power curve remained the same.

No offence mate, but all you have proven on this thread is that you don't really understand the topic.

 

[400bhp]

e. He could do the same session again tonight, .

God, no

You're correct, my HR track would likely be different (given the same power output), due to a) fatigue, b) room temperature, c)wellness, d)other stuff.

The shape of it would be similar, I would likely see a shift up or down of the curve.

And all this doesn't take into account cardio drift.

Anyway, someone a lot more knowledgeable than us lot said power is the engine and heart rate is the rev counter.

 

[Drago]

I can't justify the cost of a power meter.

I have no use for one, or even the remotest curiosity or need to know about my output.

So I didn't buy one.