There are times in our days and weeks when getting outside isn't an option when it comes to physical fitness. It may also be that you just prefer to exercise indoors. To all the indoor workout haters out there, we say...don't knock it til you try it! There are tons of options to get your sweat on inside that won't make you lose your mind (ahem -- they don't call it a "dreadmill" for nothing!). Read on for fun indoor exercise studios or programs we love.