You might know that 8 - 9 hrs sleep is recommended for general health. However, what you might not know is that WHEN you sleep is absolutely vital during recovery.

We know that physical recovery and healing takes place from 10 PM - 2 AM.

What is the science behind this time you might ask? Well, approximately 3 hrs after dark the output of ACTH of the pituitary decrease, allowing the cortisol to come down.
Elevated cortisol is an inhibitor of Human Growth Hormone (early adrenal stage insufficiency where cortisol is chronically elevated). HGH is critical for repair in body - why it is a popular supplement also btw.

An overview of factors that influence our sleep.

Your body will only enter physical and cellular repair mode in this time, if you are sleeping.

Otherwise your body will be focused on energy production mode rather than rebuilding and detoxification mode.

Why is this so important to include in a recovery program? Well, relapse happens when you are not biochemically and emotionally stable.

Recovery is not jus about staying away from your primary drug of choice.

This is a time to rebuild your body so that you can THRIVE without the use of drugs, foods and self-destructive behaviors. Repair takes place during sleep. So getting your sleep pattern right is a critical aspect of daily recovery.

Also keep in mind that repair includes includes rebuilding damaged brain chemistry coming out of an addiction or eating disorder.

You cannot use the nutrients and stress skills for much, if you do not give your body time for rest in this time window.

The time between 10 PM - 2 AM is when the building blocks would be used to rebuild and repair your house. Does this makes sense? You can't just buy the blocks (eat the foods and do the stress skill work) and expect the house to build itself. You need to give the workers time to actually use the blocks (sleeping 10 PM).

And no, you cannot shortcut this window.

You need to be asleep during the entire window here to truly enter repair mode fully. Simply because the body needs to block off some hours for general repair and every day detoxification.

When you have excess work that needs done as during recovery of any kind, you need every minute of that 4 hr time frame to be used for repair functions.

Reference: Sleep Med Clin. 2010 Dec; 5(4): 701–715