If boredom is the rut that seems to trip you up most frequently, or if you just haven't been able to find a workout you actually like, shake things up by committing to trying out a new workout class every week for the first eight weeks of the year. Many studios offer an introductory free or reduced-rate class, or you can sign up for a membership like ClassPass to explore some studios and workouts you might not normally be drawn to. How diverse can you make the lineup? Vinyasa yoga, Bikram yoga, TRX, strength training, boot camp, pole dancing, Pilates, megaformer, Spinning, lap swimming, indoor rock climbing . . . that's 11 varieties of sweat right there. Get outside your comfort zone — it just might be the ticket to getting in shape.