Sleep Schedules: How Naps can affect your Heart

In the UK, most people sleep undisturbed for around 6 hours each night. But there are many different sleep patterns, ranging from the humble afternoon nap to the space-age dymaxion sleep schedule. 

Britain is a nation of poor sleep. We're typically getting less than the seven to nine hours of sleep recommended for maintaining good mental and physical health. Almost a quarter of us frequently sleep for five hours or less each night – 43% of people have found falling asleep harder since the COVID-19 pandemic began1. Poor sleep can have a devastating impact on our motivation, mood and physical health. However, we haven't always gotten our sleep in one go. Before the industrial revolution, people frequently awoke from their slumber after just a few hours in bed. They would spend an hour or so reading, writing and chatting before returning to sleep for the remainder of the night2. Sleeping in one solid chunk is a recent phenomenon and there are a variety of different sleep schedules that have been practised throughout history. Here's a look at how and when you snooze can affect your heart.

Sleep is a vital part of staying healthy. It's when our body repairs itself and our brain processes and stores memories. Being deprived of sleep can increase your chances of gaining weight, becoming infertile and developing diabetes and heart disease. Sleep deprivation is also linked with memory loss, stress, anxiety and mood swings3. If you're aiming for a healthier heart, sleep should be a top priority. It's equally as important as following a healthy diet, taking care of your mental health and getting frequent exercise.

Most of us are monophasic sleepers, meaning we only sleep once per day. If you take an afternoon nap, you're considered a biphasic sleeper as you're sleeping twice in a day. These are by far the most common sleeping patterns worldwide, but there are other, more obscure sleep schedules. Sleeping more than three times per day is known is polyphasic sleep; this rare sleeping pattern can have many interesting effects on physical health.

Leonardo da Vinci, one of history's most prolific artists and thinkers, followed an extremely unusual sleep schedule; he slept in short 20 minute bursts every four hours, according to his diaries. This extreme form of polyphasic sleep was also followed by the Serbian-American inventor Nikola Tesla, the inventor behind many of the electrical systems we use today. For many of us, sleeping like this would be near impossible and people's attempts to follow this rigorous sleep cycle usually end in failure (as well as a significant amount of sleep deprivation).

Some people have taken the polyphasic sleep idea even further. Futuristic designer Buckminster Fuller, famous for creating the geodesic dome, invented the dymaxion sleep schedule. This intense style of polyphasic sleep involves sleeping for just 30 minutes every 6 hours; this left him awake for twenty two hours each day. After just a few years, he gave up on dymaxion sleep as his work colleagues, who slept normally, found it too impractical.

A study of 400 volunteers found that polyphasic sleepers reported higher levels of daytime sleepiness, but they also had the highest quality of sleep. They found that participants following the biphasic sleep schedule, such as having an afternoon nap, had the overall best outcomes; this group had the worst sleep quality, but were less tired during the day and more focused4.

Taking a short nap could be beneficial for heart health, according to research conducted by the Swiss National Science Foundation. They found that people who napped just once or twice per week had a significantly lower risk of heart attack and stroke. Surprisingly, the length of each nap didn't affect the risks. However, people that took more than 3 naps per week had a higher risk of heart attack and stroke. The study took people's age, sex, body weight and smoking status into account when analysing their data, but other factors including stress and lifestyle were not included and may have affected the results5.