The forbidden zone of sleep, also known as stage 1 sleep or non-REM stage 1 sleep, is the lightest stage of sleep. It occurs as we transition between wakefulness and deeper sleep. During this stage, we drift in and out of sleep and can be easily awoken. The forbidden zone typically lasts less than 10 minutes as we progress through the stages of non-REM sleep.
What happens during the forbidden zone of sleep?
When we first fall asleep, our brain waves begin to slow down from the faster frequencies of wakefulness to the slower frequencies of sleep. Brain wave activity transitions from the alpha waves of wakefulness to theta waves of early stage 1 sleep. Theta waves range from 4-7 Hz (cycles per second), indicating light sleep.
During the forbidden zone, our muscles relax, breathing slows, and eye movements stop. But we are still somewhat responsive to external stimuli. Sudden noises or movements may cause us to jerk awake. We may also experience visual or bodily sensations of falling or hallucinations known as hypnagogic hallucinations. However, we have difficulty waking up fully and may feel groggy or disoriented.
What are the stages of non-REM sleep?
Non-REM sleep progresses through three main stages:
Stage 1: Forbidden zone
- Light sleep
- Theta brain waves (4-7 Hz)
- Muscle relaxation
- Slow eye movements
- Easily awakened
Stage 2: True sleep
- Onset of actual sleep
- Brain waves slow into spindles and K-complexes
- Heart rate slows
- Body temperature drops
- Harder to awaken
Stage 3: Deep sleep
- Very deep sleep
- Delta brain waves (
- Difficult arousal
- Muscle relaxation
- Tissue growth and repair
We need to progress through the forbidden zone of stage 1 sleep before reaching the deeper, more restorative stages of non-REM sleep.
How long does the forbidden zone last?
The forbidden zone or stage 1 sleep represents the transition from wakefulness to sleep. As such, it only lasts for a brief period of time, typically less than 10 minutes.
On average, stage 1 sleep lasts:
- 5-10 minutes in young adults
- 5 minutes in middle-aged adults
- 1-5 minutes in older adults
The forbidden zone shortens as we age. Older adults spend more time in the lighter stages of sleep and less time in deep, slow wave sleep. As a result, sleep tends to become more fragmented with age.
Why is it called the forbidden zone?
Stage 1 sleep is sometimes referred to as the “forbidden zone” because:
- It’s a transitional phase, not true sleep
- We can be easily woken up
- We may not perceive it as sleep
- We can experience hallucinations and jerky muscle movements
Due to these attributes, the forbidden zone does not confer the full benefits of deeper non-REM and REM sleep. As such, we don’t spend much time in stage 1 sleep under normal conditions.
What are the benefits of the forbidden zone?
Although brief, the forbidden zone does serve some important functions:
- Allows the brain and body to wind down from wakefulness
- Triggers physiological changes for sleep – muscle/breathing relaxation
- Transitions us into deeper, more restorative sleep stages
- Permits evaluation of external stimuli for threats before proceeding to vulnerable deep sleep
Therefore, the forbidden zone facilitates our descent into sleep and helps ensure we don’t go straight from alert wakefulness to deep sleep.
What happens if we get stuck in the forbidden zone?
Under certain conditions, we may get “stuck” in the forbidden zone for longer periods of time. This can make it difficult to progress into deeper, more restorative sleep stages. Common causes of prolonged stage 1 sleep include:
- Insomnia
- Sleep apnea
- Restless leg syndrome
- Stress/anxiety
- Noise disturbances
- Light exposure
- Medication side effects
- Alcohol
- Sleep disruptions/deprivation
Spending increased time in stage 1 sleep prevents us from reaching stages 2-3 non-REM and REM sleep. As a result, sleep is lighter and more fragmented. We may feel tired and poorly rested the next day due to lack of deep, slow wave sleep.
Tips for progressing through the forbidden zone
The following practices can help you move beyond the forbidden zone into deeper sleep:
- Stick to a regular sleep-wake schedule to sync your body clock
- Develop a relaxing pre-bed routine – reading, light stretches
- Avoid bright lights, screens, and stimulating activities before bed
- Design a comfortable sleep environment that is cool, dark and quiet
- Don’t go to bed too full or hungry
- Reduce evening consumption of alcohol, nicotine, and caffeine
- Exercise regularly but not right before bed
- Address anxiety, chronic pain, or other conditions interfering with sleep
Give yourself adequate time for quality sleep by having a consistent bedtime. Make your bedroom calm and distraction-free. Healthy sleep practices will facilitate your transition through the forbidden zone into rejuvenating deep sleep.
Conclusion
The forbidden zone represents stage 1 of non-REM sleep. In this transitional phase, we move from wakefulness towards deeper sleep. Although brief, stage 1 sleep allows our bodies to relax and wind down while still evaluating environmental stimuli. Spending too long in the forbidden zone can impede progression into deeper, restorative sleep stages needed for optimal physical and mental functioning. Adopting healthy sleep habits can help regulate your sleep cycle so you smoothly pass through the forbidden zone on your way to getting high-quality, refreshing sleep.
