The gym can get a little, well, boring after a while. And why limit yourself to just the basics when there's a city of endless workout studios out there? It can be tough to narrow down all of the options, which is where we come in. New York is the epicenter of fitness, and knowing the hot trends happening in the Big Apple is often indicative on what's to come in your own city. From the Upper West Side to even Brooklyn (and everything in between), we've found the hot spots that are a must try for fitness buffs and beginners alike.