THE AVERAGE PERSON spends roughly one-third of their life asleep. Sleep is a requirement for life, right up there in importance with nutrition and hydration, yet it’s something that many people seem to feel okay about skimping on.

Scientists don’t fully understand sleep yet, but there is no question that it’s crucial to every aspect of our health and well-being. Getting enough sleep is one of the most basic forms of self-care, and there are plenty of reasons to make it a priority in even the busiest of schedules.

Understanding the Sleep Cycle

The sleep cycle is a pattern of activity in the brain that occurs repeatedly throughout a sleep session, consisting of rapid eye-movement (REM) and non-REM (NREM) stages.

• The first stage of the sleep cycle, N1, is what we often call “nodding off” and lasts one to seven minutes.
• The next stage, N2, lasts up to 25 minutes.
• Stage N3 lasts 20 to 40 minutes and represents the deepest sleep of the cycle–it’s hardest to wake someone who’s in this stage of sleep.
• We return to the N2 stage briefly before transitioning to REM.
• During the REM sleep stage, dreams occur.

After the REM stage, the cycle starts over. In typical adults, the first cycle of a sleep session usually lasts 70 to 100 minutes while subsequent cycles last 90 to 120 minutes.

Why Do We Need a Certain Amount of Sleep?

Though there’s a large body of research on the subject, scientists still aren’t clear on the specific reasons behind the pattern and length of the sleep cycle. However, they have been able to observe the effects of inadequate sleep, and it isn’t pretty.

Sleep deprivation, even in the short-term, can lead to a whole host of physical and mental problems. Even just one night of too little sleep can affect your cognitive abilities, making it more difficult to both learn new things and to recall what you already know (which is why pulling an all-nighter to cram for an exam is a terrible idea), and it has a negative impact on your emotional state, making you irritable and prone to emotional outbursts. It can cause or worsen depression, and some people may experience hallucinations. Sleep deprivation over a longer period of time can compromise your immune system and contribute to high blood pressure, heart disease, Type II diabetes, and obesity. It also increases your risk of premature death, not just by damaging your health, but also by making you more susceptible to accidents like falling asleep at the wheel.

How Much Sleep Is Enough?

The National Sleep Foundation analyzes extensive data and research regarding sleep to make its recommendations for how much sleep people need. Sleep requirements vary by age with babies and children needing more sleep than adults:

• Newborns: up to 17 hours of sleep per day
• Children ages three to five years: up to 13 hours
• Teens: up to 10 hours
• Adults ages 18 years and older: seven to nine hours
• Older adults over age 65: seven to eight hours of sleep

How to Tell If You’re Getting Enough Sleep

“Seven to nine hours” is a fairly wide range, and some people really need the full nine hours while others get by just fine at the seven-hour end of the spectrum. So how can you tell how many hours of sleep you actually need? If you wake up feeling refreshed and can make it through the day without relying too heavily on energy boosters like caffeine, you’re probably among the lucky folks getting enough sleep.

There are several cool new apps and gadgets on the market that can help you better understand your own sleep cycle. SmartWake® by Verlo is a sleep monitor that measures tell-tale signs that you are asleep by monitoring your heart rate, respiratory rate and movement. SmartWake determines where you are in the sleep cycle, then wakes you in the lightest phase of sleep within your selected timeframe via the smart alarm function. It can also help you see how factors such as alcohol disturb your sleep patterns. Tools like this make it easier to understand and appreciate the importance of sleep and can help motivate you to give it the priority status it deserves.