Training & Nutrition - watts on a stationary bike...are they even close ot accurate?

I've started back to the gym and I'm' doing 25 mins of a warm on on the stationary bike. 3 days a week and also trainer miles and outdoors riding the other days

the other day I looked at my watts and I was doing 205 .... I'm assuming that the stationary bike is probably not accurate..is this true?

my assumption is that as long as your able to bring that number up then accuracy is not really an issues as long as the number increases as your training

my little goal is by the end of my winter training I want to be able to easily spin in the 90-100 range and be at level 15 out of 20 on the bike right now I'm at level 10

it depends on the calibration of the stationary and how watts are computed

what is it, a cycleops ? then +-1.5 % accurate
SRM at the crank ? then +- .5 % accurate

some hunk of gym equipment with unknown power meter, up to +- 10% off ?


your own powertap wheel on a trainer ? +-1.5% accurate


also, your goal: my little goal is by the end of my winter training I want to be able to easily spin in the 90-100 range and be at level 15 out of 20 on the bike right now I'm at level 10

you should be able to max out the trainer and stay at 100 but it will not be easy or feel comfortable. what will
happen is you'll be able to do it, but the effort will be ginormous. it will never be -easy-, just -doable- vs having
to stop and puke....

and yes number doesn't matter as long as it climbs over time and you have something to shoot for
it doesn't matta...use the same machine though...calibration is key. even powertaps and SRM need to
be zeroed out and calibrated for accuracy.

Watts of power that you have expended and watts of power applied to the pedals are different numbers as well. You are burning calories just moving your legs around, and that depends on your body shape and weight. A lot of exercise equipment try to tell you how much energy your are burning (ie total kcalories which are just a different unit of energy)

My goal is to hit 1000 watts on a sprint, best I've got is 850 so far.

it depends on the calibration of the stationary and how watts are computed

what is it, a cycleops ? then +-1.5 % accurate
SRM at the crank ? then +- .5 % accurate

some hunk of gym equipment with unknown power meter, up to +- 10% off ?


your own powertap wheel on a trainer ? +-1.5% accurate


also, your goal: my little goal is by the end of my winter training I want to be able to easily spin in the 90-100 range and be at level 15 out of 20 on the bike right now I'm at level 10

you should be able to max out the trainer and stay at 100 but it will not be easy or feel comfortable. what will
happen is you'll be able to do it, but the effort will be ginormous. it will never be -easy-, just -doable- vs having
to stop and puke....

and yes number doesn't matter as long as it climbs over time and you have something to shoot for
it doesn't matta...use the same machine though...calibration is key. even powertaps and SRM need to
be zeroed out and calibrated for accuracy.

It is just the hunk of gym equipment

I can't see this hunk of gym equipment being that hard to max out....maybe I'm wrong but I think I can do it and if not I'll puke trying :)

Measuring wattage on exercise equipment is pretty easy from a technical standpoint, so it's simple to get accurate measurements of wattage, calories burned, etc. So what what everybody does.

Unless, of course, the people who use their machines are happier when they see numbers that are artificially inflated...

Measuring wattage on exercise equipment is pretty easy from a technical standpoint, so it's simple to get accurate measurements of wattage, calories burned, etc. So what what everybody does.

Unless, of course, the people who use their machines are happier when they see numbers that are artificially inflated...

Except wattage measured at the machine is not the same as wattage being burned by your body. Take an ergometer (rowing machine) as an extreme example. How much of your energy is going into accelerating your entire body mass back and forth along the slide? Granted it won't be huge compared to the total, but none of that energy contributes to the speed of the flywheel. So the computer has a factor built in to account for that, except they have to fudge the numbers because everybody is different, and they tend to overcompensate because people like being told that they are burning more calories.

Except wattage measured at the machine is not the same as wattage being burned by your body. Take an ergometer (rowing machine) as an extreme example. How much of your energy is going into accelerating your entire body mass back and forth along the slide? Granted it won't be huge compared to the total, but none of that energy contributes to the speed of the flywheel. So the computer has a factor built in to account for that, except they have to fudge the numbers because everybody is different, and they tend to overcompensate because people like being told that they are burning more calories.

Are you sure? I think my concept 2 measure watts as force at the flywheel only but I could be wrong. The only watts that count are the ones that apply force to move the machine. To use your erg example, if your form is terrible you use more energy to produce the same force, but that doesn't help you go faster. I don't think there is any "correction" involved.

My goal is to hit 1000 watts on a sprint, best I've got is 850 so far.

http://www.photoscene.com/kimandsteve/images/4162.jpg

:D


Watts of power that you have expended and watts of power applied to the pedals are different numbers as well. You are burning calories just moving your legs around, and that depends on your body shape and weight. A lot of exercise equipment try to tell you how much energy your are burning (ie total kcalories which are just a different unit of energy)

The body doesn't "expend watts". Watts is power, power over time is work. There is a correlation between work and calories burned, depending on the efficiency of the rider. It is generally accepted that for cycling, due to 20%-25% efficiency, 1 kj of work is roughly equivalent to 1 kcal of energy "burned" by the body.

http://www.bikeforums.net/image.php?u=141780&dateline=1225292562

I like the new avatar

The body doesn't "expend watts".
First off, a body does expend watts. A watt is just a unit to measure any power value, it is not limited to bicycle cranks. It can be directly converted into kcalories per hour, the two units are convertable and interchangeable provided you convert their values. So if you are burning kcalories in a unit of time, you are working off watts. You can measure your metabolism in watts. An average sedentary male produces roughly 100 watts of latent and sensible heat. No work is being performed.


Watts is power, power over time is work.Power over time is not work. Work over time is power. There is a difference there. And work is just a certain type of energy. The definition of power though, doesn't require work, it refers to energy.
P = E/t
P*t = E
A little bit of grade school algebra shows us that Power multiplied by time is energy. So to phrase your statement more properly, power times time is work (but only in an ideal system without any waste energy).

Cheers

On an all-out sprint, I can max-out my CycleOps fluid trainer on the biggest gear for a minute. Literally so fast that I can't pedal anymore. Max-out for me that is, meaning that the cadence is the limiting factor. (130ish)

On a gym Lifecycle, there's no way I'd be able to pull that off - at max resistance, it's so tight that I'm literally standing on the pedals and they're barely moving. I think gym bikes have a LOT more resistance than trainers.

On an all-out sprint, I can max-out my CycleOps fluid trainer on the biggest gear for a minute. Literally so fast that I can't pedal anymore. Max-out for me that is, meaning that the cadence is the limiting factor. (130ish)

On a gym Lifecycle, there's no way I'd be able to pull that off - at max resistance, it's so tight that I'm literally standing on the pedals and they're barely moving. I think gym bikes have a LOT more resistance than trainers.

the lifecycles in my gym max-out at 500 w

First off, a body does expend watts. A watt is just a unit to measure any power value, it is not limited to bicycle cranks. It can be directly converted into kcalories per hour, the two units are convertable and interchangeable provided you convert their values. So if you are burning kcalories in a unit of time, you are working off watts. You can measure your metabolism in watts. An average sedentary male produces roughly 100 watts of latent and sensible heat. No work is being performed.

Power over time is not work. Work over time is power. There is a difference there. And work is just a certain type of energy. The definition of power though, doesn't require work, it refers to energy.
P = E/t
P*t = E
A little bit of grade school algebra shows us that Power multiplied by time is energy. So to phrase your statement more properly, power times time is work (but only in an ideal system without any waste energy).

Cheers

I apologize, I tried to simplify and I used imprecise terms. You are of course correct. I didn't mean over time as divided by time, I meant "for a time", as in multiplied.

On an all-out sprint, I can max-out my CycleOps fluid trainer on the biggest gear for a minute. Literally so fast that I can't pedal anymore. Max-out for me that is, meaning that the cadence is the limiting factor. (130ish)

On a gym Lifecycle, there's no way I'd be able to pull that off - at max resistance, it's so tight that I'm literally standing on the pedals and they're barely moving. I think gym bikes have a LOT more resistance than trainers.

I know it seems like cadence is the limiting factor but I just hammered on my new CycleOps Fluid 2. I'm 6'3" and 256 pounds and my cadence reached 162. I know I can hit a higher speed on my Road bike but I don't want to trash my Frame. I was clipped in on a GT mountain bike with a 42/12 gears.

Max Speed:48.9 mph (Garmin Calibrated wheel sensor)
Max Cadence:162
Also verified on a Garmin Edge 405.
2500+ Watts on my Kinetics Computer(I doubt it's very accurate) for just a few seconds.
I think I maxed the 50mph top speed on the kurt kinetics computer?

Tomorrow I'll have a 2008 green Kirt Kinetics Pro Road machine being delivered by UPS. I'll film it if no one believes I can break 2K++ watts output on it. I think it has a little more resistance at top speeds then the Cycleops Fluid 2.

you didn't do 2500 watts; that computer is not remotely accurate. It does not measure power, it infers power through wheel speed and an assumed resistance curve . You could show a video if the computer screen but it would not mean anything...

you didn't do 2500 watts; that computer is not remotely accurate. It does not measure power, it infers power through wheel speed and an assumed resistance curve . You could show a video if the computer screen but it would not mean anything...

I just setup the Kurt Kinetics Pro Road machine. That thing has way more resistance then the Cycleops Fluid 2. The 18 pound flywheel really changes the dynamics. It takes much more energy and time to get it up to speed. Even with the 6 pound flywheel it takes much longer to reach top speed and top speed seems at least a few mph less at the same effort. Kinetics claims this trainer is calibrated to within 3% accuracy. I'm guessing I'll hit 1800-2000(inaccurate trainer watts) on it for 5 seconds.

BTW: I was a sprinter for 8 years and ran the 40 in 4.4 at 215 pounds. I've put on more muscle since then.

1010 watts at 112bpm? That can't be right. What was your heartrate when you hit 1010watts?

1010 watts at 112bpm? That can't be right. What was your heartrate when you hit 1010watts?

the picture shows max power, but hr from the moment the picture was taken, after I got home and jumped off the bike. My hr at peak power was about 130, but because it lags effort, it eventually got up to the low 170s...

http://www.photoscene.com/kimandsteve/images/4163.png

What level racer are you? I guess I would be somewhere around Cat 8, if they had such a thing.

What level racer are you? I guess I would be somewhere around Cat 8, if they had such a thing.

I'm a mid-pack cat 4, but I managed to win a race right at a fitness peak. I'm nowhere near my peak right now... and guys like Waterrockets can put out much more power than I can, even factoring in weight.