Individuals vary, and our need is greater at different stages in our life, but we all know that we need about 8 hours of sleep a night. What we don’t all know is that the quality of the sleep we’re getting (or not getting) matters too.
As you sleep, you cycle through light, deep, and REM sleep. In light sleep your brain is processing emotions and memories and your body is in regulation and maintenance mode. As our muscle activity slows we sometimes get that muscle ‘jump’ feeling or feel like we’re falling. Our body temperature drops, and heart rate slows.
As we enter deep sleep our brain goes ‘offline’ and into delta, we stop dreaming, and our bodies are growing and repairing, and our immune system is strengthened. In REM sleep, our brain lights up again and our bodies are ‘actively paralysed’, we’re dreaming, processing emotion and memory and our cells are making proteins.
We’re in light sleep most of the time (around 60% of the time). We’re in deep sleep around 15% of the time, our bodies have a natural deep sleep requirement and once we hit it, the rest of our sleep is light or REM, but if we don’t hit our deep sleep requirement we don’t wake refreshed. Injury, illness, sleep disorders and shift work (deep sleep is a night thing) all have a negative effect. The rest of the time we’re asleep (around 25% of the time) we’re in REM sleep and if we don’t get enough, it negatively impacts our memory and we wake groggy and struggling to focus. If we get too much we can wake more irritable and anxious. Anti-depressants can cut REM sleep time in half.
To regulate your sleep quality, avoid caffeine after 2 pm, and eating, working out or using smart devices within 2 hours of bed and try switching your devices to low-blue light mode after dark and sleeping in a cool pitch-black room. If your phone is your alarm, put it on airplane mode.