I sleep about 9-10 hours a day during the winter. I know it's a lot, but I work out quite a bit, work a late schedule, eat healthy, and still find time to do yoga and meditate consistently. I feel almost as if it's a hibernation mode.
During the summer I sleep considerably less, generally 78 hours. It seems the best way to maximize productivity and increase energy levels within the body and mind is to wake up an hour or so before the sun comes up, go outside and breathe as the nitrogen levels are increased and help you to wake up, (not to mention the cold). Take a cold shower, drink about 23 teaspoons of apple cider vinegar diluted in some V8, the vegetable drink, with some wheatgrass powder blended in. Keep a healthy diet and balance the acidity with alkalinity throughout the day!