Stay hydrated and well fed

Remember, even though it's winter and freezing, you still need to hydrate yourself throughout the day, before, during and after the workouts.  Water is very important for many body functions - including cooling ourselves off when we sweat (come on - you know we sweat during the workouts).  Food is also important - during the holidays it becomes more difficult to eat healthy and maintian healthy weight.  Make sure you have a small snack 1 hour before a workout - as long as it doesn't upset your stomach during the workout.  Some good carbs and protein will do the trick - it's up to you on how you do it, since everyone has different likes / dislikes when it comes to food.