Sleep is how our bodies re-generate. It's how we repair, if you will. When you participate in vigorous exercise (yes even doing "it" for you gutterminds, lol) you push your body to the limit. This is indeed a good thing as the harder you push it, the more it will adapt to the hard work.Getting enough rest after all that is crucial. Your body NEEDS rest days between workout days. I personally train Mon, Wed and Fri. The rest of the week, I rest (well, as much as I can anyway). 7-8 hrs sleep is the goal. Not only does this promote muscle gains, it also elevates mental alertness. It also helps increase productivity when you are working at your job, around the house, etc. Do I always get that much? Not with little ones around that wake up during the night on occasion, but I do try for at least that much. Other benefits include reducing inflammatory proteins in the blood, keeping your weight in check, lowering overall stress levels and can keep you from feeling depressed. One of the biggest things I have found is if I keep a schedule, and go to bed at a targeted time every night, then I usually will get enough sleep so I can function throughout the day and not feel tired all day. Again, it doesn't always happen, but I do try. Bottom line, get your rest. It's good fer ya....