One Rhythm to Rule Them All
Regardless of how nice it is to sleep in during weekends, your body can really handle only one rhythm at a time. The closer you can keep your weekend rhythm to the one you have during weekdays, the more energy you'll have next week, and the better you will perform.
Choose a suitable wake-up time for the weekend and stick to it. It doesn't have to be exactly the same as on weekdays, but the closer, the better.
Consistency essential, but so is getting enough sleep. If you are planning on waking up early, you need to go to bed on time. Choose a bedtime that fits your planned wake-up time beforehand. Place an alarm a couple of hours earlier to make sure you remember to start preparing yourself to bed. Take into account the time it takes before you fall asleep in bed.