Gyms often ban glass bottles because of the hazard they create when dropped/shattered.
I personally use a hard (i.e. not squeezable) plastic bottle, that I fill with cold/cool water just before use. As long as the water has not been sitting in the bottle for days or in the sun or in a hot car, etc. I don't think there is enough potential chemical leeching to worry about.
I personally use a hard (i.e. not squeezable) plastic bottle, that I fill with cold/cool water just before use. As long as the water has not been sitting in the bottle for days or in the sun or in a hot car, etc. I don't think there is enough potential chemical leeching to worry about.