Shoot for 7.5 - 8 hours. If you make it that far and you wake up a few minutes before your alarm goes off you should be fine.

How is your sleep environment? marksdailyapple.com has some good suggestions for creating an optimal sleep experience (blackout shades, no artificial lights, no tv/computer beforehand). There may be some other issues, but optimizing your environment is a good start.

This could be normal. I haven't checked their sources yet, but La Leche's newest version of their breastfeeding book claims that sleeping for 8 hrs straight is more a cultural adaptation than a biological norm. They say it's more normal to sleep for a few hours, wake up for a few late at night, then go back to bed. (They make this claim mainly about adults, as part of their attempt to encourage parents to do those night feedings instead of try to train the infant to sleep through them.)

On top of that, it's well documented that different people have different sleep needs, and diet and age can affect it. For example, my father could usually function well on 4 - 6 hours of sleep several days in a row. I have a friend who, since she hit middle age, gets up at two or three a.m. because she simply can't sleep any longer. And I'm functioning on less sleep, and am more clear-headed in the mornings, since I dropped the grains and sugar.

So I'm with Ralph; how do you feel? Does it feel like you're getting enough sleep? Or are you struggling to make it through the day? If the latter, having some tryptophan foods or a bite of sugar-free chocolate near bedtime might help!

I would suggest eating more carbs. If youre Crossfitting 4-5 days a week you NEED carbs. I Crossfit between 4 and 6 days a week and doing VLC hurt more than it helped...I tracked everything I ate, and gained 5 lbs while Wodding regularly. Kind of defeats the purpose of VLC right?

I used to be a terrible sleeper, and now I sleep from about 9/10 PM and wake up around 7 almost every night. Don't IF and do VLC because that will stress your body out even more and raise cortisol. Try adding some carbs back in, keeping protein high, and lower your fat a bit (as Id assume its quite high on VLC). You say youre ususally dead by the afternoons in your comment to Frugal Jen...VLC does not support high intensity workout. Its great if you are into a lot of walking and just heavy lifting. Crossfit is not that whatsoever...you NEED to feed your body for your activity. I swear you will feel better by adding in lots of veggies, fruits, and some starches PWO. You will have more energy and strength within the week. I feel like once you get your body fed your sleep will improve.

Check out leangains.com if youre interested in IF. Berkhan is all about cycling your carbs and fats on workout and rest days.

I have similar problems. I still wake up at night but have improved the quality of my sleep and how fast I fall asleep.

What has helped me:

1. Dark curtains on windows - My window faces right onto the street and all the light from street lights shines directly into my room. I never realized how full of light my room was until I put up the curtains.
2. Air Filter - The quality of the air in your home is usually pretty bad. There is dust floating around and it at least for me it affected my sleep. After putting in an air filter I found I could get to sleep a lot faster. It also provides the secondary benefit of some white noise that blocks out random sounds.
3. Covering up or removing any artificial light.

Hope this helps you.

Eat some starches!!!! Have a potato with your dinner - works wonders