Getting enough sleep is incredibly important for both physical and mental health. However, in our busy modern lives, many people find themselves trying to function on very little sleep. So is 2 hours of sleep per night enough? Let’s take a look at what experts say.
How much sleep do we need?
The National Sleep Foundation recommends that adults aged 18-64 get 7-9 hours of sleep per night. For older adults aged 65+, the recommendation is 7-8 hours. Children and teens need even more sleep – between 8-10 hours is recommended. So in general, less than 7 hours of sleep per night is considered inadequate for most people.
Getting enough sleep allows your body and brain to recharge. During sleep your body repairs muscles, consolidates memories, restores energy, and releases important hormones. Skimping on sleep prevents these vital functions from happening and can lead to negative consequences.
Consequences of insufficient sleep
Here are some of the effects of chronic sleep deprivation (getting less than 7 hours regularly):
- Impaired brain function – difficulty concentrating, mood changes, poor memory
- Weakened immune system – more prone to getting sick
- Increased risk of chronic disease – heart disease, diabetes, stroke
- Weight gain – imbalance of hormones that regulate hunger
- Decreased performance – motor function, productivity, reaction time
- Increased risk of accidents – drowsy driving crashes
As you can see, regularly getting insufficient shuteye can negatively impact nearly every system in your body. Let’s see why getting just 2 hours of sleep is particularly problematic.
Is 2 hours of sleep enough?
Getting just 2 hours of sleep in a 24 hour period is considered acute sleep deprivation. This is an extremely inadequate amount that is not sustainable over many days. Just a single night or two of getting 2 hours of sleep will result in:
- Fatigue and sleepiness the next day
- Difficulty concentrating and remembering things
- Impaired judgement
- Increased stress hormones like cortisol
- Changes in mood – irritability, anxiety, depression
If repeated night after night, getting just 2 hours of sleep can also increase your risk for chronic diseases and conditions like obesity, heart disease, high blood pressure, and diabetes.
Stage 1 vs REM sleep
Sleep has different stages that you cycle through multiple times each night. The two main stages are:
- Stage 1 – Light sleep, easy to wake up from
- REM – Deep sleep, dreaming occurs, hardest stage to wake up from
When you get just 2 hours of sleep, you miss out on that crucial REM stage. REM sleep is when your body and brain recharge, so without it you wake up feeling unrested. Even if you sleep deeply in those 2 hours, it’s not enough time to complete all the sleep cycles your body requires.
What research says
Numerous sleep studies have looked at the impact of acute sleep deprivation. Here is some of what the research has found about getting just 2 hours of sleep in a 24 hour period:
- Greatly reduced cognitive performance – equivalent to being legally drunk (Dawson & Reid, 1997)
- Significantly worsened mood – increased anxiety, irritability, depression (Kahn-Greene et al, 2006)
- Severely impaired motor skills and reaction time (Belenky et al, 2003)
- Increased risk of weight gain and insulin resistance (Spiegel et al, 1999)
Based on these findings, it’s clear that getting just 2 hours of sleep is detrimental to both your mental and physical health.
Who can function on little sleep?
Some people claim they can train themselves to need less sleep. But research shows that consistently getting fewer than 6 hours of sleep negatively affects performance no matter what. Your body simply needs a certain amount of sleep to function properly.
That said, there are rare individuals who have a gene mutation that allows them to thrive on less sleep. For example, a mother and daughter were studied who got just 4-6 hours of sleep per night but showed no cognitive deficits. But these short sleepers represent less than 1% of the population.
Tips to function on less sleep
While there is no way to overcome the negative effects of sleep deprivation, here are some tips to help you get through the day after getting minimal shut-eye:
- Take a nap – 20-30 minutes can help improve alertness and performance
- Have caffeine – up to 400 mg appears safe for most adults
- Do light exercise – gets the blood pumping to help combat grogginess
- Eat healthy – avoid fatty, sugary foods which can make you sleepy
- Practice good sleep hygiene – stick to a schedule to get back on track
However, it’s important not to rely on these measures frequently. The only way to truly fix insufficient sleep is to get more high-quality sleep consistently.
The bottom line
Getting just 2 hours of sleep in a 24 hour period is not adequate for normal functioning. It can impair your cognitive abilities, emotional state, and general health and wellbeing. While an occasional night of little sleep won’t cause lasting harm, routinely getting this little sleep can have serious consequences.
Aim for 7-9 hours of sleep each night as recommended. Establish good sleep habits like sticking to a schedule, limiting screen time before bed, and making your bedroom comfortable and dark. Getting sufficient, high-quality sleep should be a priority for everyone.
References
Dawson, D. & Reid, K. (1997). Fatigue, alcohol and performance impairment. Nature, 388(6639), 235.
Kahn-Greene, E.T., Killgore, D.B., Kamimori, G.H., Balkin, T.J., & Killgore, W.D. (2007). The effects of sleep deprivation on symptoms of psychopathology in healthy adults. Sleep Medicine, 8(3), 215-221.
Belenky, G., Wesensten, N.J., Thorne, D.R., Thomas, M.L., Sing, H.C., Redmond, D.P., Russo, M.B., & Balkin, T.J. (2003). Patterns of performance degradation and restoration during sleep restriction and subsequent recovery: A sleep dose-response study. Journal of Sleep Research, 12(1), 1-12.
Spiegel, K., Leproult, R., & Van Cauter, E. (1999). Impact of sleep debt on metabolic and endocrine function. The Lancet, 354(9188), 1435-1439.