Great question, sleep is often an overlooked component of health and fitness! Good timing too, I've been on a search for the perfect night's sleep and have been experimenting a bit with this. I tend to get 6 or 7.5 hours of sleep per night, depending on my schedule. The 90 minute intervals seem to help (for me, at least), as that's the typical length of a full sleep cycle. Waking up at the same time every day whether you have to or not is great as well.

One thing I've realized is the amount of time you are asleep is not necessarily as relevant as the quality of sleep you're getting. There are some cool gadgets and apps out there that can track your sleep (ie amount of time in REM, deep sleep, times you wake up per night, time to fall asleep, etc). I'm a giant dork about sleep and with some minor adjustments to my schedule and diet I feel so much better on 6 hours than when I used to get 9 or more back in the day. If you're interested, google "sleep hacks" and you'll probably find some interesting advice! Will be more than happy to share my personal dorky experiences if you're interested (some of them are REALLY nerdy lol).

It's important to note that more sleep (and better quality) is significant when on a strength training program such as SL to facilitate muscle recovery.

I had to prioritize sleep this year and am just an overall better person for it. As it relates to lifting--I can definitely tell. My Saturday a.m. lifts (where I sleep about 9 hours) are always my best ones.

I need 8-9 as well, but have a small person who often wakes me up. Sleep is sooooo important. It helps lower our cortisol levels (think stress), helps our bodies recover better, and makes us all nicer.

Some good tips -
1. Put the screens away after dinner. The light from monitors and devices makes our brains think we shouldn't be sleepy. I say this as I type on a screen - but I have started checking books out from the library again so that I will finish out the night with paper instead of pixels.
2. Set an alarm to go to bed. I set mine at 9. That means that hopefully I'll be turning out the light by 10. Again, totally breaking my rules, but the aforementioned small person took a long nap today and wanted to PARRRR-TTTAAAYYY!
3. If you aren't taking magnesium, and it's not contra-indicated for another medication you are on or by your healthcare professional, give it a shot. It's the second most common vitamin deficiency in most industrialized nations, and is used in every single cellular process. It makes a big difference in my ability to go to sleep easily, to stay asleep all night, and to wake up feeling good. There is a ton of double-blind, reputable research out there about the efficacy of magnesium. I prefer the Natural Calm brand.
4. This one seems obvious, but is easy to forget. Don't drink a lot in the evening. Because you'll get up to pee, and that's annoying.

Those are things I've done to really put sleep up there as a priority. I also nap whenever I get the chance (not often), and try to really listen when my body says to rest. It's tough, but the payoff is totally worth it.