Are you an early bird or a night owl? And does it matter? It does for one key group of people, according to a world-first study.
Diabetics who go to bed early are more likely to be in better health and more physically active compared to night owls.
The study conducted by the Universities of Leicester and South Australia assessed the bedtime habits (sleep chronotypes) of people with type 2 diabetes.
It found that people who went to bed late and got up late, or ‘evening chronotypes’, often have an excessively sedentary lifestyle characterised by low levels and low intensities of physical activity – and this puts their health at risk.
Lead researcher Dr Joseph Henson, from the University of Leicester, says understanding that sleep preferences can affect levels of physical activity could help people with type 2 diabetes to better manage their health.
“There is a massive need for large-scale interventions to help people with diabetes initiate, maintain and achieve the benefits of an active lifestyle,” Dr Henson says.
“For people who prefer to go to bed later and get up later, this is even more important, with our research showing that night owls exercise 56 per cent less than their early bird counterparts.
“Exercise plays an important role for people with diabetes, helping maintain a healthy weight and blood pressure, as well as reducing the risk of heart disease – all significant factors for improving diabetes management.
“This makes understanding the factors that can mitigate a person’s propensity to exercise, extremely important.”
The researchers say type 2 diabetes mainly results from excess body weight and physical inactivity. Worldwide there are 463 million people with the disease, a number expected to rise to 700 million by 2040.
This is unsurprising, given 1.9 billion adults are overweight, with 650 million obese.
UniSA’s Dr Alex Rowlands says the study provides a unique insight into behaviours of people with type 2 diabetes.
“The links between later sleep times and physical activity is clear: go to bed late and you’re less likely to be active,” Dr Rowlands says.
“As sleep chronotypes are potentially modifiable, these findings provide an opportunity to change your lifestyle for the better, simply by adjusting your bedtime.”
“For someone with diabetes, this is valuable information that could help get them back on a path to good health.”
Medical site Healthline says the amount of sleep you get affects “everything from your weight and metabolism to your brain function and mood”.
“When you fall asleep, your brain and body go through several cycles of sleep. Each cycle includes four distinct stages. The first three stages are part of non-rapid eye movement (NREM) sleep. The last stage is rapid eye movement (REM) sleep.”
It takes, on average, about 90 minutes to go through each cycle. If you can complete five cycles a night, you’d get 7.5 hours of sleep a night. Six full cycles are about nine hours of sleep.
“Ideally, you’ll want to wake up at the end of your sleep cycle, which is when you’re most likely to feel the most rested,” according to Healthline.
A sleep calculator can help you figure out what time to go to bed based on your wake-up time. For example, Healthline’s chart says if you need 7.5 hours of sleep and wake up at 6.30, you should be hitting the hay at 10.45pm.
Researchers in Germany found that sound sleep also improves immune cells known as T cells, which play an important role in the body’s immune system.
Kimberley Hardin, M.D., director of the sleep medicine fellowship program at the University of California Davis, says good sleep is vital.
“People underestimate the importance of sleep, and less than seven hours per night on a regular basis has negative effects. It essentially creates a fight-or-flight state, with increased stress hormones and release of adrenaline,” she told Healthline.
“Sleep is like anything else in the body,” Dr Hardin said. “It’s a natural state and has to be taken care of to be healthy. Sleep should leave you feeling refreshed, not groggy and struggling. Realistic expectations are essential. And sleep changes as you age, so you may not feel as rested as you did when you were a younger.”
Less than five hours sleep per night on a regular basis is associated with higher mortality and having less than seven hours sleep for three nights in a row has the same effect on the body as missing one full night of sleep.
“Bad sleep can result in long-term problems with mood, memory, and blood sugar, among other things,” Suzanne Stevens, M.D., a sleep neurologist at the University of Kansas Health System, told Healthline. “Short-term consequences of bad sleep may include sleepiness, poor judgment, car accidents, moodiness, memory problems, workplace mistakes, and more.”
A good night’s sleep is also thought to help protect against heart disease.
Why sleep is not a snore
Sleep is crucial for many reasons. A good night’s sleep:
- regulates the release of hormones that control your appetite, metabolism, growth, and healing
- boosts brain function, concentration, focus, and productivity
- reduces your risk for heart disease and stroke
- helps with weight management
- maintains your immune system
- lowers your risk for chronic health conditions, such as diabetes and high blood pressure
- improves athletic performance, reaction time, and speed
- may lower your risk of depression.
How to improve your sleep health
During the day
- Exercise regularly but try to schedule your workouts at least a few hours before you go to sleep. Exercising too close to bedtime may lead to interrupted sleep.
- Increase your exposure to sunlight or bright lights during the day. This can help maintain your body’s circadian rhythms, which affect your sleep-wake cycle.
- Try not to take long naps, especially late in the afternoon.
- Try to wake up at the same time each day.
- Limit alcohol, caffeine, and nicotine in the evening. These substances have the potential to interrupt your sleep or make it difficult to fall asleep.
- Switch off electronics at least 30 minutes before bedtime. The light from these devices can stimulate your brain and make it harder to fall asleep.
- Get into the habit of a relaxing routine before bedtime, like taking a warm bath or listening to soothing music.
- Turn down the lights shortly before bedtime to help your brain understand that it’s time to sleep.
- Turn down the thermostat in your bedroom. 65°F (18.3°C) is an ideal sleeping temperature.
- Avoid looking at screens like the TV, your laptop or phone once you’re in bed.
- Read a book or listen to white noise to help you relax once you’re in bed.
- Close your eyes, relax your muscles, and focus on steady breathing.
- If you’re unable to fall asleep, get out of bed and move to another room. Read a book or listen to music until you start feeling tired, then go back to bed.
A good night’s sleep is essential to good health. If you’re having trouble falling asleep or staying asleep, consider talking to your doctor. They can help determine if there’s an underlying cause.
Do you get enough good sleep? Have you ever used a sleep calculator?
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Disclaimer: This article contains general information about health issues and is not advice. For health advice, consult your medical practitioner.