What is a good way to start up your metabolism again?

Exercise: Exercise, Exercise, Exercise, Exercise, Exercise, Exercise, Exercise.

Speed metabolism.: Weight training builds lean muscle which is metabolically active around the clock, day and night. While some studies suggest that cardiovascular exercise may stimulate the metabolism for as much as 48 hours after the exercise, it may be much less time. Both are best in combination. As well, eating a small healthy meal of lean protein and complex carbs every 2-3 hours speeds the metabolism.