This is what happens when I let my mind wander.....

I've been hitting the gym a bit more recently, and while thrashing away on the rower, I started thinking about how accurate the calorie counter might be.

You need to use a set number of calories to move a set weight a set distance (in a set time?). So, when I row away I make the flywheel spin, the computer thing knows how heavy it is, how fast it's moving, and how far I've moved it in a session. So working out the calories that the flywheel has taken is fairly easy maths.

The bit I've been wondering is if the manufacturers put in some fudging there to account for your body not being 100% efficient, or if the calories they show are just relating to the flywheel - if so, and you burn 500 calories in a session, how much would you need to add on for the body's efficiency rating?

They really need to put TVs in front of the rowers at my gym

Thanks all,


Vince

As far as I know they read the theoretical number of calories burned by the average person, rather than the simple mathematical calulation of energy. If you're unfit you will probably burn more and if you're very fit you'll burn less.

Time does not come into how much energy is burned (theoretically, although it does for a human) - how quick you do something is related to the power required:

Work done (energy) = Force * Distance
Power = Force * Velocity

Energy = Power * Time

The machines will probably work out the instantaneous power being dissipated and use that to work out the energy used.

[Edited on 5/6/08 by matt_claydon]