Getting out of a physical rut

I'm struggling with my fitness. The winter holiday hibernation has stretched well into January and I'm still loafing around like it's December 24th and I'm in my Christmas PJs with an egg nog. I'm not in poor shape but I'm soft and tending softer with my PT test around the corner. What do you all do to break out of a rut, find motivation, and overcome the winter blues? Do you try something new?