The bike knows my height and weight and that’s about it. From that it can calculate how my body burns calories?

Every body is very different, so I don’t see how any calculation can be accurate.

  • NineMileTower@lemmy.world
    link
    fedilink
    arrow-up
    16
    ·
    1 month 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
      link
      fedilink
      arrow-up
      16
      ·
      1 month 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
      link
      fedilink
      arrow-up
      11
      ·
      edit-2
      1 month 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, which starts averaging out to the same amount of calories. I bet they also raise the amount of calories shown to account for no process being 100% efficient.

      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, but in a positive way. (You burned more than the counter said). Some will record your body mass index and other info to try to shift you in the right average.

      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. All in all calories aren’t a great way to think about human strength, or exercise

      • Eheran@lemmy.world
        link
        fedilink
        arrow-up
        3
        ·
        1 month 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?

    • zaph
      link
      fedilink
      arrow-up
      6
      ·
      1 month ago

      I think it’s one of those things where the average is close enough for most people.