Sleep is a much-loved thing that is often mishandled. Although most of us enjoy and understand the importance of a good night’s kip, we still often fail to get enough of it. Especially for runners, sleep plays a fundamental role in repairing tissues, regulating hormones and reducing your risk of injury – and it also supports daytime focus, alertness and overall mental wellbeing.
The NHS recommends that adults aim to get between seven and nine hours of sleep each night. However, according to research, recreational runners who ‘consistently push their limits’ and clock more miles than most should aim to hit the upper end of this recommended range, or even exceed it, to stay healthy and train most effectively.
But getting enough quality sleep is not the only thing that runners need to think about. As it happens, there’s another sleep factor to bear in mind – and it’s one that could have a major impact on your heart if you’re of a certain age.
Specifically, a 10-year investigation published in BMC Cardiovascular Disorders found that people between the ages of 40 to 60 who went to bed at varying times each night were more likely to have heart problems than those with a consistent bedtime schedule. So, before you tuck in, make sure that you read this.
What did the study find?
The researchers tracked the sleep and wake-up times of 3,231 people – all of whom were 46 years old at the start – to get an idea of their usual bedtime schedules. They spent the next 10 years combing through the medical records of each person to monitor the trajectory of their health.
During those 10 years, 128 people experienced a major heart event – events ranged from unstable angina, stroke and heart failure to cardiac-related death. After controlling for factors like BMI and cholesterol, the common denominator among this group was that their bedtimes were all over the place.
The risk for heart problems was doubled in people who had a shifting sleep schedule and received less than eight hours a night. Meanwhile, waking up at different times of the day did not make a difference in heart risk.
‘Our findings suggest that the regularity of bedtime, in particular, may be important for heart health,’ says Laura Nauha, PhD, postdoctoral researcher at the University of Oulu and lead study author. ‘It reflects the rhythms of everyday life and how much they fluctuate.’
Why is a consistent bedtime important for heart health?
Sleep is governed by your circadian rhythm, which is a biological clock that optimises the timing of your bodily functions. This ‘clock’ works on a roughly 24-hour schedule and is responsible for when your body decides that it’s time to eat, rest and wake up. Sudha Tallavajhula, MD, neurophysiologist and sleep medicine specialist at UTHealth Houston, explains that the circadian rhythm is also in charge of hormone fluctuations, heart rhythms and blood pressure – all of which factor into a healthy heart.
When you continue to change your bedtime, it disrupts your circadian rhythm, says Grant Bailey, MD, cardiologist at South Denver Cardiology and AdventHealth Littleton. As a result, stress hormones and adrenaline increase, which can affect heart rate and blood pressure. Hunger hormones can fluctuate, too, leading to poor food choices. Plus, with continued sleep deprivation, the risk of anxiety and depression rises, which may indirectly strain your heart even further.
Most importantly, Dr Tallavajhula says that the shift in metabolic efforts from movement and digestion to repair, hormonal regulation and memory consolidation all happens during sleep. This housekeeping mode is necessary for recovery of the heart and the brain. ‘Poor sleep keeps the heart under consistent stress and does not allow for recovery time,’ she says. ‘We understand now that all three aspects of sleep – quality, quantity and timing of sleep – are all equally important.’
How to train your body to sleep at a regular bedtime
In the digital age, getting to sleep at a decent hour each day is hard – but it’s not impossible. Cardiologist Samanatha Benin, MD, says that it’s all about going back to the basics.
‘Sleep hygiene revolves around giving yourself a winding down time, eliminating social media and TV use and setting up your bedroom space for perfect sleep with no lights or outside world stimulation,’ says Dr Benin. ‘In a world of constant stress and external factors, it’s important to prioritise ourselves – and our sleep should be at the forefront of that.’
Dr Bailey emphasises that you should start winding down a minimum of one hour before your intended bedtime. ‘Avoid caffeine, exercise and stimulating activities for that one-hour period to let your mind slow down and prepare for rest,’ he says. ‘If you still have a long to-do list, studies have shown that it helps to even write down what is on your mind so that you don’t keep thinking about it after bed.’
The first few days might be a little rough – you may toss and turn while trying to will your body to sleep. But before you give up to mindlessly scroll through TikTok, Dr Tallavajhula says to wait 10 to 15 minutes. If you’re still wide awake, get out of bed and sit in a chair and read or listen to something monotonous until drowsiness sets in again. Over time, your mind should make the association that the bed is only for sleep.
Dr Bailey has some encouraging advice: ‘Healthy sleeping patterns are what your body wants to do naturally, so once you are in a routine, you may find that it gets much easier over time.’
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Jocelyn Solis-Moreira, MS is the associate health & fitness for Men’s Health and has previously written for CNN, Scientific American, Popular Science, and National Geographic before joining the brand. When she’s not working, she’s doing circus arts or working towards the perfect pull-up.
Rachel is Runner’s World UK’s Senior Content Writer, covering all running-related topics from training advice and gear reviews to race reports and elite runner profiles. Formerly a Website Content Editor and Content Manager at London Marathon Events and The Running Channel respectively, Rachel is well-versed in the running scene and understands what it takes to put on some of the biggest running events in the world. A 2:50 marathoner, she would much rather run 26.2 miles than race a 5K and has currently completed 11 marathons, including five of the six Abbott World Marathon Majors in a sub-3 time. She now hopes to run the Tokyo Marathon to complete the set and become a Six Star Finisher.