Sleep restriction therapy is a type of cognitive behavioral therapy for insomnia that aims to improve the quality and duration of sleep. It involves limiting the amount of time you spend in bed to the actual amount of time you sleep. The main focus of this treatment is on "sleep efficiency," which is the ratio of the amount of time you spend in bed to the amount of time you actually sleep.
The first thing you should do is keep a sleep journal to determine the average amount of time you spend sleeping each night, and limit your time in bed to that amount. For example, if your average sleep duration is 6 hours, you should try to spend only 6 hours in bed each day.
Initially, because you're spending less time in bed, you're also spending less time sleeping, which can lead to fatigue. However, remember that sleep restriction therapy works by putting individuals into a state of mild sleep deprivation, which increases the desire to sleep and makes it easier to fall asleep.
If you sleep at least 85% of the time you spend in bed, then gradually increase your sleep duration by 15-30 minutes until you can get 7-9 hours of normal sleep.
Sleep restriction therapy can be difficult in the short term because you may experience increased fatigue and difficulty falling asleep during the adjustment period. However, studies have shown that it can be an effective treatment for insomnia in the long term.
The key to actually improving your sleep habits with sleep restriction therapy is to set and maintain a regular sleep schedule based on your sleep diary.