's Forum Archives - Racing

Archive Home >> Racing(1 2 3 )

Power Training(7 posts)

Power TrainingRockyMountainRacer
Apr 5, 2002 1:27 PM
I thought I'd start this thread based on the "weight" topic posted below by LeGrimper. I just want to know if anyone on this board is training with these newfangled power meter thingies, or even knows anyone who is. I don't understand why anyone needs to spend $800 on this stuff. It seems to me that it is pretty easy to know how hard you are going by what your legs feel like--after only one summer of training with a heart rate monitor I can easily tell when I hit my anaerobic threshold. Therefore, I think the hrm was a great tool for teaching me how hard was hard enough for a certain kind of workout, but now I don't even use it that much. So why do you need something to tell you what your power output is for a given level of exertion? Who cares?
Overly simple answerBipedZed
Apr 5, 2002 1:47 PM
Other than the occasional pro I see around the area I don't personally know any riders who train with power meters, although last weekend I did see a guy on the Red Rocks ride with a PowerTap.

From what I understand measuring power is the most direct way to gauge fitness. And the most useful measurement of fitness is sustained power (in watts) at LT. The trouble with using heart rate is that heart rate is an effect of producing power, e.g., on a given day, producing 100 watts to go 20mph may cause a heart rate of 140 bpm. In a 40K TT you may average 300watts at 27 mph with a heart rate of 170 bpm. The problem lies with heart rate being variable based upon your rested state. If you are overtrained, you may have to push to 175 bpm to produce the same power you could last week at 170 bpm. Power is power, heart rate is the measurement of your engine's exertion to make that power.

To sum up, measuring power with heart rate is a much more direct way to train than with heart rate alone.
Who cares?!allervite
Apr 5, 2002 3:53 PM
Power, is the most important variable in the equation of how fast you are and can be. It does not matter if your AT is higher than the moon. If your power is low, you're gonna get wamped. I have known a lot of very fit athletes that sucked as bike racers. So what good is an HRM? All of the pros that can afford them are using power meters to train with now.

In my opinion an HRM is great for base and fitness work, but not much good for intenstiy. Thresholds change a lot more than people think, and there are so many variables that affect your heart rate (dehydration, heat, etc.). Even the effort at which you are performing can supress your heart rate. Did you ever notice that after a really intense effort, your heart rate actually rose right after you sat up?

Now, after that little rant, I must admit that Power Meters are way too expensive; and even if they were a hundred bucks, I still probably would not use one. I prefer the old fashioned listen to your body strategy. Although I would not recommend it to anyone who has not done years of training with an HRM, power meter, or coach. My biggest limiting factor in my athletic career was stupid training; and the scary thing is that I believe I knew more about training than most of the guys I raced against.
I train with powerDuane Gran
Apr 5, 2002 9:12 PM
I recently purchased a power sensor for my Polar S-710 and really like it. There is a potential for information overload, but in general it really ads a dimension to training. That isn't to say that it guarantees results, but racing generally comes down to producing high power for sustained time intervals. A power meter is the best tool I can think of to track progress at this.

There are a variety of additional benefits. For example, the Polar software has shown me that I tend to favor my right leg at high cadence. It also shows me that my power output increases as my pedaling index (a measure of efficiency) increases. Based on these two factors, I see potential for increasing power without increasing strength. If I can do it, it is almost like getting something for nothing. I'm not sure how I would learn about this, analyze it and track it without a power meter.

But then, I'm the sort who gets into doing that kind of thing. Mind you, I also enjoy just riding the bike. ;)
Power sensor questionsspeedisgood
Apr 6, 2002 6:22 AM
I heard about the Polar power sensor but never heard much about the actual mechanism of measuring or estimating power. Can you tell me how it does it and how accurate it seems to be?
You can never have too much powerLeGrimper
Apr 6, 2002 3:42 PM
Expensive YES but what’s expensive? Campag Record?

I think Power tools will become an essential tool for the future........IF you want to maximise your training and progress.

Your power output at a given HR increases as you become stronger, fitter, more skilled and with power you can track these changes and concentrate on where you are deficient. The difference over months can be quantified whether you are winning races or not! Are you actually improving?

Too expensive? Those new Campag Wheels are expensive and are still only round with spokes, and will Ksyriums really add much to your performance.

Drafting the devil here.
Le Grimp
answer (sort of)Duane Gran
Apr 6, 2002 7:43 PM
I'm on a mailing list through called "wattage." Among the many informed members (I don't consider myself one of these) the inventors of the technology are on the list. To paraphrase from them:

"The polar power sensor is like a guitar pickup that sits on the chain stay and detects the chain frequency. It also measures the chain speed with another sensor. Coupled with the chain length and weight it can calculate power in watts."

When people first hear about this they are rather skeptical because it sounds weird, but it actually works very well. The SRM and PowerTap use strain guages, but all methods are simply indirect ways of interpreting power. SRM is the gold standard for power measurement since they have been doing it for 10 years. You might be interested in this document produced by Polar that compares accuracy with the SRM:

To summarize, they find that it is accurate within 1.7%. In my opinion this is accurate, and certainly good enough for analyzing and improving performance. Accuracy can however be negatively affected by poor installation.

If money weren't an issue I think I would have an SRM, but I'm pleased with the Polar solution thus far.