What happens when we sleep?

Our bodies go through four to six sleep cycles a night, each made up of four stages. Throughout the first three stages, heartbeat, breathing and brain wave activity reach their lowest levels and muscles relax. The deep sleep achieved in stage three plays a vital role in physical and mental recuperation.

However, during the fourth stage known as REM (rapid eye movement) sleep, there’s as much activity in the brain as when we’re awake. This is believed to support key functions such as memory and learning. It’s also when the most intense dreaming takes place.

The sleep-wake cycle

Our bodies are governed by circadian rhythms — 24-hour cycles that are part of our internal body clock. One of the most important is the sleep-wake cycle. It aligns our waking and sleeping with day and night and, as light exposure decreases, it prompts the release of the hormone melatonin. This helps you drift off into a sleep that restores and recharges you, keeping you healthy in body and mind.

The sleep-wake cycle can be disrupted by several different factors, including shift work, travelling across time zones and our lifestyle choices also play a big part.

Why sleep is essential

If the sleep-wake cycle is thrown off balance, it can lead to lower quality or disturbed sleep. Over time, this can bring a range of health challenges, including cardiovascular problems, a weakened immune system and a greater risk of obesity. And our mental health suffers too.

Studies have shown that even after a single night’s bad sleep, we have far lower positivity levels and fewer positive feelings, such as sympathy and friendliness. Anxiety and stress levels increase too.

Recent Harvard Business Review research also cites the negative impact of sleep deprivation on our ability to stay calm at work and build the working relationships required to be an effective leader.

But don't worry, even when we work in music, there are small tweaks we can make to our sleep routine that can help us improve our sleep.