I wouldnt take more than 3 days off. Let your body fully recover and then hit it hard. But you may want to consider adjusting your work out regiment. I dont know what your workouts include, but if you feel like shit cause you are overtraining, then cut back your workouts in a day. Here's a few tips. Never do more than 1 hour of lifting. If you lift hard, you shouldnt be able to last that long. If you do both running and lifting in a day, have a minimum of 5 hours between them. If you dont let your body recover, you may have adverst effects. Drink a ton of water, get proper nutrition, and sleep for a minimum of 8 hours.