One of the girls at my gym that took a gymnastics practice break and is coaching says she lost a lot of weight from not doing the regular gymnastics practice. She says it's from losing muscle. I guess muscle weighs a lot.

Muscle is more dense than fat, so if you lose a lot of muscle it won't show as much on you as if you lose fat, but it will show on the scale.

Lots of the girls gain weight though after like a 2 weeks break for vacation from not exercising, guess it depends on body type. Like if you have the body type that you don't gain fat so much, and then you don't have gym practice and lose muscle, then you will lose weight on the scale. Muscle is really good though!!