The way that clothing slows an athlete down has been commonly well known, for many years. The outfits have been getting more skimpy and restrictive to address this, through years. I went into a trendy athletic clothing store last spring. Some of it is very revealing and looks like underwear for outerwear. I saw a couple of young women out running the other day in sports bra and a bikini bottom like thing. Much of the butt bottom exposed. Still, even with all of the stretch, the breath-ability, and disappearance of fabric, nothing will substitute nudity.
Underwear-like garments are coming to the trails and many a professional hiker has mentioned hiking naked, or skinny-dipping. Swimming/sunning attire...well you know. So, the naked and the dressed for exercise are merging. Give time time.
Jbee