So I'm on my crappy TM at work and it says I was cranking out 200 watts. The thing is junk, it didn't even ask for my weight to come up with this so I know it's meaningless. But it got me thinking, is watts something you can even calculate accurately? After a quick google search, it wasn't clear.
Anyone know or have a link to a calculator?
Watts is joules per second. Joules is newtons times meters. Newtons is mass times acceleration.
Watts=J/s, J=Nm, N=kg*m/s^2
Physics is wonderful wrote:
Watts is joules per second. Joules is newtons times meters. Newtons is mass times acceleration.
Watts=J/s, J=Nm, N=kg*m/s^2
So if I'm running at a constant speed, what's my acceleration? Acceleration of gravity?
energy and calories burned meters on exercise equipment is pretty bunk. If you were an out of shape huffing fatty, busting a nut to do a workout for the first time in years, it'd be close to accurate. For the average endurance athlete, far from it. In the past when I've been injured, I haven't found it too difficult to burn "1000 calories" in an hour.
Divide by your weight by your run time.
No
On a treadmill, shouldn't your weight not be a factor in calculating watts. Watt is a measure of work. When an object's velocity is held constant at one meter per second against constant opposing force of one newton the rate at which work is done is 1 watt.
The rate of work, the speed of the rotation of the treadmill belt against the resistance of the belt, is the same regardless whether the person who is moving the belt is 150 or 200 pounds.
Running outside is different and weight does come into play.
minong wrote:
Physics is wonderful wrote:Watts is joules per second. Joules is newtons times meters. Newtons is mass times acceleration.
Watts=J/s, J=Nm, N=kg*m/s^2
So if I'm running at a constant speed, what's my acceleration? Acceleration of gravity?
pretty sure yeah. In that case 9.8 m/s^2. So if your mass is 60 kg and you're going 3 m/s. Then you can use those equations and definitions above to figure out how many watts your using.
But obviously the treadmill doesn't know your mass so it probably just tells you how much power (meaning watts or energy per unit of time) it's using, based on the rotation speed of the belt.
dalongi wrote:
On a treadmill, shouldn't your weight not be a factor in calculating watts. Watt is a measure of work. When an object's velocity is held constant at one meter per second against constant opposing force of one newton the rate at which work is done is 1 watt.
The rate of work, the speed of the rotation of the treadmill belt against the resistance of the belt, is the same regardless whether the person who is moving the belt is 150 or 200 pounds.
Running outside is different and weight does come into play.
50/50 chance you are a troll, or just wrong. I cant tell.
Can elastic energy be accounted for?
In cycling or rowing it's just pure muscular effort. Everyone has to cycle or row in the same manner, running can be done a hundred different ways.
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Google: watts running calculator
Alan
math made easy wrote:
Divide by your weight by your run time.
That only works in the Southern hemisphere.
Physics is wonderful wrote:
minong wrote:So if I'm running at a constant speed, what's my acceleration? Acceleration of gravity?
pretty sure yeah. In that case 9.8 m/s^2. So if your mass is 60 kg and you're going 3 m/s. Then you can use those equations and definitions above to figure out how many watts your using.
But obviously the treadmill doesn't know your mass so it probably just tells you how much power (meaning watts or energy per unit of time) it's using, based on the rotation speed of the belt.
It is astonishing that anyone could believe that this is what the treadmill is reporting.
Where do you people come from?
dreamin wrote:
dalongi wrote:On a treadmill, shouldn't your weight not be a factor in calculating watts. Watt is a measure of work. When an object's velocity is held constant at one meter per second against constant opposing force of one newton the rate at which work is done is 1 watt.
The rate of work, the speed of the rotation of the treadmill belt against the resistance of the belt, is the same regardless whether the person who is moving the belt is 150 or 200 pounds.
Running outside is different and weight does come into play.
50/50 chance you are a troll, or just wrong. I cant tell.
Has to be a troll. Just has to be.
Global math wrote:
math made easy wrote:Divide by your weight by your run time.
That only works in the Southern hemisphere.
OK, finally a smart answer!
Maybe use the Gravity Ordered Velocity Stress Score. That's still only an estimate of power since some of it is statistically based.
In the meantime, just use the same machine and the same incline every time and the initial values can be used as benchmarks whether they're accurate or not in absolute terms.
Watts aren't that necessary a metric for running anyway. Power is used a lot more often in cycling and in rowing, where factors such as wind conditions and temperature (which affects air density/aerodynamic drag) make day-to-day comparisons of performance and training status very difficult to measure by only relying on velocity (as in a time trial effort or in interval training), even if the same course is used each time. Comparing performances on different courses is even more difficult (specifically in cycling, where hills, clothing, and the quality of the road surface come into play) without looking at power (watts) as the standard of effort. For indoor cycling, measuring watts can be extremely useful. Even setting up the same bike on the same trainer with the same number of turns to the resistance unit and using the same gears can produce small workout-to-workout variations in resistance based on air pressure in the rear tube, how worn the rear tire is, how centered the rear wheel's contact patch is on the roller bar and gradual loss of resistance to the wheel from potential mechanical factors during a workout. So using a power meter is the most reliable way of determining true effort in that case.
But don't worry about trying to use (or even measure) watts in running. Pace, duration and RPE are where it's at.