Let's face it: As the month of December progresses, there seems to be less and less time to work out. Instead of trying to fit in the various elements of your workout, try just being sport specific. If you run, make sure you have time for your regularly scheduled runs and if you can fit in some weight training, great. If not, it is OK to skip strength training for a couple of weeks. If you cycle, get on your bike and get three rides in a week.
If you don't train for a specific sport, then aim for working out at least three times a week. Remember if you are pressed for time, adjust your workout by shortening your routine, don't eliminate exercising altogether.