This particular spot, on Álvaro Obregón and Orizaba (or thereabouts, si no me equivoco), is fabulous because one of the best ice cream spots in all of D.F. (I tried the avellana/hazelnut and it was ridiculous) is right next to this gym, where, insanely, people dancercise in front of a huge picture window, which happens to have a big old seating area in front of it. So people seriously plop themselves down and hang out for a bit, enjoying the guys' and gals' moves. And it's not like they pretend to read their book or whatever; they sit there and watch.
I was tempted to join them ... with my ice cream. But I opted to take a quick photo from afar and take off for further exploration of this charming neighborhood.