Should I be worried?...?
Answers:
yeah, the sweat will darken your leather unless you use protectant really, really often.....get you a yoga mat and lay down on until you have dried up (and do yoga, its awesome)
Other answers:
yes, too much moisture will eventually ruin leather. not to mention your sweat is not only moisture, it has a lot of chemicals in it.
yes, too much moisture will eventually ruin leather. not to mention your sweat is not only moisture, it has a lot of chemicals in it.
don't sit on a red leather couch, sit somewhere else instead
you should be worried! any moisture will destroy your leather sofa
With time the leather will be ruined. In addition, it is unhygienic.
I wouldn't worry too much. Your sweat is most likely to sweet to do any lasting harm to the leather.
The oils & salt in your sweat will stain your leather couch. If you must sit on it --cover it .