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Presuming conservation of mass to be true, mass has to go somewhere if i lose weight. Doing workout i burn my fat to do some work but then where does that fat go?


marked as duplicate by John Rennie, probably_someone, Aaron Stevens, Qmechanic Feb 11 at 16:00

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    $\begingroup$ Related: physics.stackexchange.com/q/2605 $\endgroup$ – probably_someone Feb 11 at 15:42
  • $\begingroup$ @Chair I disagree. Is the above possible-duplicate to this question with 107 upvotes also unrelated, then? $\endgroup$ – probably_someone Feb 11 at 15:43
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    $\begingroup$ Possible duplicate of How does mass leave the body when you lose weight? $\endgroup$ – John Rennie Feb 11 at 15:43
  • $\begingroup$ @probably_someone Indeed, I do believe that exact duplicate should be off-topic too, but since it looks like a rather unpopular opinion, I'll assume that such questions are, in fact, within the site's scope, and I'll retract that VtC. $\endgroup$ – user191954 Feb 11 at 15:45

In the simplest model, your body burns chemicals containing carbon, hydrogen and oxygen that you eat and store with oxygen that you inhale. This produces carbon dioxide and water which you exhale.

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    $\begingroup$ Excretion and sweat are also channels by which mass leaves the body, though the former would (hopefully) not be very relevant to exercise in particular. $\endgroup$ – probably_someone Feb 11 at 15:42

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