Flocked wallpaper. Purple-velvet settees. A disco ball so big it houses the D.J. booth. Although it looks like a plush goth-tinged hotel, David Barton’s sprawling (40,000 square feet) new four-story gym in the former Barnes & Noble is a serious facility with a boxing room, plentiful weights, and a yoga studio (4 Astor Pl., nr. Broadway; 212-505-6800; from $125 per month). The newest Derek Jeter–brand 24 Hour Fitness, opening in September on the top three floors of a former warehouse, feels like a Soho loft, with original beams and massive windows. (136 Crosby St., nr. Houston St.; 212-918-9811; price on request). Pure Yoga’s gigantic (20,000 square feet) Upper West Side location, opening in December, will have eight studios, with bamboo and cork floors, and hot-pink yoga mats (204 W. 77th St., nr. Broadway St.; 212-877-2025; from $140 per month). Finally, the popular spinning-only Upper West Side gym SoulCycle—known for its candlelit classes and motivational mantras—will be opening two locations, on the Upper East Side (September 21; 1470 Third Ave., at 83rd St.; soul-cycle.com; $32 per class) and in Tribeca (mid-December; 101 Warren St., at West Side Highway).