From what I have read, I think all of us need 7-9 hours of sleep per night. Where we fall in the range can depend on who we are, our age (what we need can change over time), and other daily factors. If we are training over 10 hours per week, we may need a little more. If we are very stressed during the day, perhaps we need a little more than usual; but for the most part we each have around a set point that will work well. We can find that if we have the opportunity to not set an alarm for a period of time until we fall into a natural rhythm. The reason it can take awhile to find that rhythm is because so many of us are not getting enough and are so far from that cycle that it takes awhile for our bodies to adjust.
And sleeping less during the week and trying to catch up on the weekends has been shown not to work. (See also, this wonderful book called The Promise of Sleep by William Dement).
Sleeping too much in an attempt to catch up can throw us off into the future. I recently experienced this when we were traveling. We were staying in a camper van and it wasn’t that close to the large comfortable bed that we have at home. I woke up often to change positions, with pain on one side or another. And since we were camping, and there was quite a long evening of dark, we would often be in bed for longer than 8 hours. After a night of not sleeping well, I often slept great the next night and would let myself sleep in. Then, having gotten too much sleep the night before, I wouldn’t sleep well the following night, and I ended up in a poor cycle of sleeping well every other night.
It just highlighted that in my own life, I do much better with consistent sleep nightly, even on the weekends.
Where do you fall? Is this an area to experiment with? Might you do better with more overall, or just more consistency throughout the week?