A lot of people use it to lose water weight also. Like if you have to weigh in for something and not actually do the physical exercise that day. I did a powerlifting competition where they weighed me on thursday and we didn't actually lift until saturday. So I lost ten pounds durring the course of thursday (through the bike and the sauna, and I don't reccomend anyone do this) and weighed in for the weight class below my normal weight. Turns out, everyone in that weight class did the same damn thing. Anyway, back to the point, sauna's are also used to lose water weight.
Bookmarks