The calories spent to work an exercise bike can be measured in terms of how much energy is needed to turn the pedals—it’s independent of whatever’s doing the turning.
If that’s the case, why does height and weight matter?
Comment on How is the calories meter on exercise bikes accurate
AbouBenAdhem@lemmy.world 2 months ago
A calorie is a unit of energy—it’s used to measure how much energy is contained in the foods you consume, and how much energy your body outputs in the form of physical work. These are objective measurements that have nothing to do with your body’s internal biology—you could measure the energy input and output of a robot or a car the same way.
visor841@lemmy.world 2 months ago
NineMileTower@lemmy.world 2 months ago
So it’s a measurement of the mechanical force needed to run the machine, but does one human body burn as many calories as another to exert the same force on a stationary bicycle?
marcos@lemmy.world 2 months ago
Your muscles’ efficiency varies widely on short exercise bursts, and very little on long, constant sessions.
It’s not clear to me what the bike is calibrated to, I’d say it’s correct to set it for long sessions, but I’d expect them to vary widely from one mode to another.
RedditWanderer@lemmy.world 2 months ago
It’s a measurement of energy needed. Bodies are going to take different amount of force to move the thing, but it’s also going to take a different amount of time, and impart less inertia.
Measuring how we consume our calories is also a bit tricky, the bike tells you the minimum energy you spent moving the wheel. It could be slightly more, but not by much because our bodies are pretty efficient at using stuff to burn into energy. The amount needed to move the bike is about as much as we’ll burn because there isn’t a lot of waste. Of course if you have a condition, or are out of shape this changes and the counter becomes more inaccurate.
We still calculate how much calories are in food by burning them and seeing how much energy they emit (heat). It’s not really how we consume calories but very similar.
Eheran@lemmy.world 2 months ago
Humans are about 25 % efficient. Not bad, but also not that good. So factor 4 to wherever actual work you did. The question is: Does the bike take that into account already?
RedditWanderer@lemmy.world 2 months ago
Is that 25% efficient at burning calories to produce force or inefficient at converting food into usable calories?
I meant to say in the spending of our calories through our muscles
zaph@sh.itjust.works 2 months ago
I think it’s one of those things where the average is close enough for most people.
ccunning@lemmy.world 2 months ago
Yeah - there must be some calculation done to estimate inefficiency.