Training & Nutrition - elliptical watts measurement accuracy?

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TwoTyred
03-22-07, 08:48 AM
i understand the METS, HR and some other values
are more specific to the individual, but, on a gym
elliptical trainer, is the pwr reading just a generalization
or is it real?

many thanks!!

CdCf
03-22-07, 01:16 PM
It ought to be fairly easy to calibrate such a machine accurately, but whether they do it or not, I have no idea...
CastIron
03-22-07, 03:06 PM
I have an elliptical at home that measures wattage. I can't think of why the wattage numbers would be significantly off. Having said that, based on heart rate, the wattage you produce on that machine will not translate to the number you'll see on a bike. Ballpark, perhaps. The elliptical seems easier and based on the numbers (nearly 4w/kg/hour on a really good day--3w/kg/hr average) it would make me one hell of a cyclist. I'm not. One can dream, though.

CdCf
03-22-07, 03:38 PM
It could be that it shows your estimated total power output, not just the power going into the machine.

On a bike, the efficiency is about 20% for a normal cyclist. That means your total power output is five times the power going into the pedals. What the efficiency is for an elliptical, I don't know.
TwoTyred
03-22-07, 05:57 PM
yeah, the HR etc, is an estimate based
on 'average' this and that, but what i
was wondering was if the watts were
based on what was actually being pushed
into the machine.

And yes, i was amazed, comparing my
own HR monitors numbers on the elliptical
to what it reads on the real bike--it's a whole
lot harder on the bike, i have no idea why?
especially since that's what i have all my
experience on!?
ericgu
03-22-07, 10:16 PM
I have an elliptical at home that measures wattage. I can't think of why the wattage numbers would be significantly off.

The answer to your question is, "because people like to see big numbers when they work out."

I don't know if they do this specifically with the wattage figures, but I know they do it with the calorie measurements.
will dehne
03-23-07, 03:11 PM
A little warning.
The Courtyard by Marriott has a very nice and expensive elliptical trainer. I got carried away and tried to see the maximum wattage I could sustain for one hour. I did not record the exact number but it was well over 1000 watts.
I suffered knee problems afterwards which I have never had before. I stopped doing that and went back to spinning on a bike trainer. The knee problem disappeared but it did scare me.