MindProbe

I've heard many people say that a power meter is the most accurate way to measure effort. But this makes no sense to me. A PM does not measuring effort, it measures performance. It's attached to the engine's output; it's what you get for your effort. Effort is a metric of what's going on inside the engine, and this is what PLE and HRMs are about - measuring the stress that gives you a particular level of output.

Why is this hard?

Carbon Unit

I agree that a pm measures performance but that is a good indication of performance gains. I would think using a stop watch and timing a regular ride would also show performance gains.

bikerjp

Subscribed. This should be good.

achoo

Because you've never ridden with a HRM or power meter?

denvertrout

Your first premise is wrong - A PM doesn't measure your effort, it measures your output. An increase in HR does not mean an increase in effort. Sit in a chair and drink some coffee, do you get an increase in HR while sitting there? Too many variables with PLE to be an accurate indicator of effort.

MindProbe

Irrelevant. Please try reading my post.

MindProbe

that's not my premise. My premise, that I've heard many people say that a power meter is the most accurate way to measure effort, stands.

Maybe, but it is a good indicator of stress.

achoo

I did.

So, have you ridden with a HRM or power meter?

achoo

Stands on what? You've presented nothing to support that.

No, it's a good indicator of heart rate.

And if by stress you mean "how hard you're working", HR is related to stress.

But it isn't a "good indicator" of it.

MindProbe

OK - so you are a master at dancing around the issue. Can we get to it now?

ericm979

The stress you're seeing in the HR isn't just the stress that causes training adaptations and performance improvement. It's all kinds of stress, training and other. Other stresses like bad day at the office, too much coffee, dehydrated. All of those raise HR but don't have a training effect.

And of course you're wrong to discount measuring performance. Performance is what counts, not effort. The goal is to be a faster rider, not to suffer more.

MindProbe

Where did I discount it? I said a PM was a means of measuring it. Just as a cycling computer, or a tape measure and stop watch are. And, for the record, they both count.

hhnngg1

I see your point - you're right. For 'perceived' effort, the best metric is your brain, which perceives the effort.

The problem with this is that your brain can perceive efforts quite differently with different situations. You may be redlining in a racing paceline but so caught up with focusing on the pace and rotation that you don't perceive the effort as that hard, which sets you up for a big bonk/dropoff in the later part of the ride. Similarly, you might think you're going hard on an early AM workout, but are really not doing the workout much justice since you're not fully awake.

The PM measures output - you're right it doesn't measure perceived effort one bit. It's a more reliable, more objective number, but for sure you'll have days where for the same power output you may have a perceived effort of "5-6" versus "9-10" depending on your fatigue and training load. They really look at different things, but in most cases, the objective PM numbers will be more reliably reproducible and objective than the much more variable and subjective RPE.

I've found HR to be a pretty decent surrogate for a PM in the right circumstances (steady state training) - it's sort of in between the objectivity and precision of PM vs RPE.

Interestingly, all 3 are useful together as they all measure slightly different things. And also interestingly, you can absolutely get a lot faster with none of them.

jmX

As a person who has multiple power meters, hr monitors, hr->power meters, and a bookshelf full of books on the subject I feel like I should join in here, but I'm not even sure what the discussion is. Is this really about how some people use the word "effort" as a synonym for "output"? Yes, people will say "nice effort!", when they really meant "nice performance".

achoo

I'm not the one making assertions about performance vs effort. You are.

Define your terms clearly, make your assertion. Then support it with evidence.

Bacciagalupe

HRM's have a few issues. The main one is that a lot of people don't do enough testing to get an accurate maximum heart rate, which can change as fitness improves. There are some minor issues, such as cardiac drift, which can make HRM's a little more inaccurate as an event goes on. HRM's are still useful, because they're cheap, simple, and easy to use on a variety of bikes or events.

The advantage of the power meter is that it's a reliable, consistent, and reasonably accurate measure of how much power gets to the meter. It doesn't directly measure how hard you're actually working to put out X amount of power, but is still a better training tool in many respects than an HRM. The downsides are that they are expensive, complex, and some models can't be easily moved to different bikes.

So basically, pick the tool that fits your style, needs and budget.

svtmike

In the history of the 41, only 13 threads contain all four words "power meter measures effort". This is one of them. I don't think you have substantiated that you really have heard many people say that.

I don't disagree with you that a PM measures output. RPE doesn't gauge effort, though -- it crudely gauges perceived effort which as others have stated might be quite different from the effort and has a moving standard against which it is gauged. HRMs are about measuring heart rate, not stress or effort. That's as much an output of the engine as power although it is typically delayed.

An athlete paying attention to all three can learn quite a bit about himself and his response to different situations, objectively assess his fitness level and fatigue level, as well as make training decisions such as stopping a workout that has much too high an RPE for the output achieved.

Homebrew01

Ple ?

MegaTom

You tell us, you're the one that seems to be having a problem here...

MegaTom

I think he meant pie.

AconfusedBoy

Go buy the book "Power Meter Handbook, A User's Guide for Cyclists and Triathletes" by Joe Friel. After reading the first chapter you will know why Power Meters are so much better than other methods. Other methods can be used in combination with the pm but nothing else compares to it on it's own.

Other than that, listen to people that know what they are talking about. You know, those people that have actually used a power meter before.

MindProbe

Perceived Level of Effort

halfspeed

Define "effort".

MindProbe

Well, I'm new here, so I don't know about this forum. I just know I've heard a lot of "power advocates" say the meters are the best way to measure effort, and I've read it in many places. Example: "Using a power meter enables you to measure you effort through watts".


https://www.trisports.com/powermeters.html

MindProbe

How difficult it is, both physiologically and psychologically, for a rider to perform at a given level for some time period.