875 WEST END AVENUE

Far beyond being a trend, gyms, also known as health clubs and fitness centers, are becoming as ubiquitous as lobbies and elevators. You'd be hard put to find a single new-construction condominium that doesn't have one, and many older cooperatives and condos, anxious to stay up-to-date, are weighing the option so as not to look like dumbbells. "If you don’t have one, you’re at a competitive disadvantage," says Deanna Kory, a senior vice president and associate broker at Corcoran Group Real Estate. "There are people who look at two similarly sized apartments who will be swayed to the building with the gym — often."