Why Doesn't Sleep Refresh You?

Feeling tired? Does it seem like sleep isn't restoring you? Even if you go to bed on time and sleep the recommended amount, that doesn't guarantee your sleep is necessarily restful and restorative. Why doesn't sleep refresh you, and why do you feel tired the next day?

Poor Sleep Quality Makes You Tired

If sleep worked like a light switch, sleeping would be simple. A light switch has exactly two settings: it's either on or off. Sleep, however, is a far more complex phenomenon. It consists of multiple levels known as sleep stages. Unlike a traditional light switch, it works more like a dimmer, with different settings for the level of illumination.

The transition from wakefulness to the land of dreams happens through light sleep stages. During light stages, sleep is delicate and susceptible to external disturbances. Gradually, the sandman adjusts the dimmer settings darker and sleep deepens. During deep sleep, a person sleeps soundly and doesn't easily wake up even to loud noises or disturbances.

From deep sleep, the transition continues to the REM stage. REM sleep is exceptional in the sense that it resembles wakefulness in many ways. During the REM stage, the eyes move beneath the eyelids and brain activity measured during sleep closely resembles that of the waking state. However, the body's muscles become completely relaxed and immobile. Dreaming typically occurs during the REM stage.

Deep sleep is not automatically more refreshing or restorative than other sleep stages. Sleep is refreshing and restful when all sleep stages are in proper balance with each other. Quality sleep includes not only deep sleep but also light sleep stages and REM sleep. If sleep becomes one-sided in terms of any sleep stage, or if a stage is entirely absent, sleep quality deteriorates and sleep doesn't refresh as it should.

You Don't Always Notice Fragmented Sleep

The continuity of sleep is extremely important for sleep quality and its restorative power. Uninterrupted sleep is the most refreshing of all. This is due to the cycle of sleep stages. Sleep stages alternate during the night in approximately 90-minute sleep cycles. One cycle begins with light sleep and progresses through deep sleep to the REM stage. A new cycle then begins again with light sleep.

If you wake up in the middle of a cycle, the sleep cycle starts over. If the awakening happens mid-cycle, the sleep stages that were scheduled for later in the cycle go unrealized. Regular nighttime awakenings lead to an increase in light sleep at the expense of REM sleep and deeper sleep stages.

Fragmented sleep is light, restless, and one-sided in terms of sleep stages. Nighttime awakenings and arousals are often so brief that you don't even remember them in the morning. That's why many people may suffer from fatigue caused by fragmented sleep without even knowing it.

Alcohol Is the Worst Poison for Sleep

If you want to sleep really poorly and wake up tired in the morning, here's a good tip: drink a glass of wine in the evening before going to bed. Alcohol has traditionally been considered a good sleep aid, but in reality, it's the worst possible poison for sleep quality.

Alcohol makes sleep deeper especially in the early part of the night, but at the same time, it displaces almost all REM sleep. Without REM stages, sleep becomes one-sided. Additionally, alcohol makes sleep in the early morning hours fragmented and superficial. Overall, sleep becomes restless and not very restorative or refreshing. The amount of alcohol consumed is not the decisive factor for sleep quality. If you want to sleep well, even one glass in the evening is too much.

Sleep Should Be Restorative

Poor sleep quality creates sleep debt just as much as sleep deprivation does. Constant fatigue is not a natural state for anyone and takes a toll on health in the long run. Fortunately, you can influence your sleep quality through your own choices. The backbone of quality sleep is built on good sleep hygiene and a regular circadian rhythm.