Читать книгу The Art of Sleeping: the secret to sleeping better at night for a happier, calmer more successful day - Rob Hobson - Страница 36

ese stages of sleep are very much about your body as the thinking parts of the brain go ‘offline’. During deep sleep your body secretes the human growth hormone to help rebuild and repair cells of tissue, bone and muscle. Stages one to three also help to strengthen the immune system. Age can impact the sleep cycle, as you spend more time in light sleep and less time in these stages of deep sleep as you get older. STAGE FOUR While the previous stage of deep sleep is all about the body, stage four – or REM – is focused on the brain, because it is at this point in the sleep cycle that it is most active. Your body will largely remain inactive but your eyes will move rapidly in different directions. During this stage your heart rate increases and your breathing becomes more irregular. Protein synthesis also peaks, helping to maintain the processes required to keep your body working properly. Dreaming usually occurs in this fourth stage, as well as the regulation of emotions and memories.