It sounds backwards: to sleep more, spend less time in bed. But sleep restriction is the engine inside CBT-i — the first-line, drug-free treatment for chronic insomnia — and it works precisely because it's uncomfortable for a week or two.
Sleep restriction therapy (SRT) is the most powerful single component of cognitive behavioural therapy for insomnia (CBT-i). The idea is simple: instead of lying in bed for nine hours hoping to catch seven, you deliberately set a shorter time-in-bed window that matches how much you're genuinely sleeping right now. If you currently sleep about six hours out of eight in bed, you start by allowing yourself roughly six hours in bed — no more. The name is misleading; you're not restricting sleep, you're restricting the wide-awake time you spend lying down.
Two things happen. First, a tighter window builds sleep pressure — the natural drive to sleep that accumulates the longer you're awake — so you fall asleep faster and wake less. Second, the bed stops being a place you associate with frustration and clock-watching, and re-associates with sleep. The measurable result is rising sleep efficiency: the share of your time in bed actually spent asleep. As efficiency climbs into a healthy band — researchers generally use about 85–90% — you gradually widen the window again, fifteen minutes at a time, until you find the most time in bed you can hold at high efficiency.
A good window is anchored to your natural wake time, not a moralised early bedtime. You pick a fixed wake time you can keep every day, then count backwards by your target time in bed to get a bedtime. Each week you titrate: if efficiency held in the target band, add about 15 minutes; if it stayed low, trim 15 minutes. Responsible programmes never push the window below roughly five hours, no matter how fragmented sleep is — going shorter is neither safe nor sustainable. The whole method is a feedback loop: measure efficiency, adjust the window, repeat.
The first week or two is genuinely hard. Cutting time in bed means you'll be sleepier during the day before things improve, so it's risky if you drive long distances or operate machinery. More importantly, sleep restriction has real contraindications: it can destabilise bipolar disorder, lower the seizure threshold in people with epilepsy, and worsen untreated sleep apnea. If any of those apply — or you're pregnant — this should only be done with a clinician. This article is general information, not medical advice.
Classic SRT runs on a sleep diary: every morning you log when you went to bed, how long you took to drop off, how often you woke, and when you got up — for weeks. It's the part most people abandon. Vitra has a dedicated CBT-i view that does the bookkeeping for you. It reads your efficiency and awakenings from your Oura data, plots an efficiency trend against the 85–90% target band, draws a wake-up heatmap that shows the clock hours you tend to wake, and — as an opt-in — offers a sleep-window suggestion anchored to your own median wake time and sized to your recent sleep, titrating up or down as your efficiency moves. Everything is computed locally on your machine, and the prescriptive window stays gated behind a toggle precisely because of the contraindications above.
Local AI on your Mac or PC. One-time purchase, 7-day trial, no subscription.
Download Vitra →