The BHF investigates recent headlines that claim catching up on sleep on Saturdays and Sundays could lower your risk of heart disease by a fifth. Lots of us enjoy a lie-in at the weekend, especially if our busy schedules have made it hard to get enough sleep during the week.

But could staying in bed for an extra few hours on a Saturday and Sunday really cut the chances of having a heart attack or stroke?

That’s what UK media outlets reported in August after early findings from a new study suggested that catching up on sleep missed during the week may lower the risk of heart and circulatory diseases by up to 20%.

The research, presented at the European Society of Cardiology Congress in London, examined data from over 90,000 British people in the UK Biobank study to see whether extra sleep at the weekends had any effect on their risk of having a stroke or developing coronary heart disease (which can lead to a heart attack), heart failure or atrial fibrillation.

The researchers from China put participants into groups depending on whether they had more or less sleep at the weekend than they did in the week. These groups included those who had:

• The most sleep: between one hour and 28 minutes to 16 hours more sleep at the weekend.
• The least sleep: between 26 minutes and 16 hours less sleep at the weekend.

They found that people who got the most extra sleep at the weekend were 19 per cent less likely to have a heart or circulatory disease over the 14-year study than those who got the least sleep.

The finding was even starker for those who were classified as ‘sleep deprived’, which were people who said they slept less than 7 hours a night during the week.

In this ‘sleep deprived’ group, people who had the most extra sleep at the weekend had a 20 per cent lower risk of heart disease than those who had the least sleep at the weekend.

The findings led the researchers to conclude that catching up on sleep at the weekends is linked to lower rates of heart disease, especially among those who are sleep deprived.

What do the researchers say?

In their summary, the researchers said they carried out the study because, despite many people sleeping in on their days off, there was a lack of research “examining whether compensatory weekend sleep has positive effects on heart health”.

Their new findings mirror previous research that found people who sleep less may have a higher risk of heart disease.

A review of 18 studies published in 2023 in the journal Biomedical Reports found that being sleep deprived (defined as having less than 5 or 6 hours of sleep a night in most of the studies) was linked to a 9 per cent higher risk of heart and circulatory diseases.

But previous research into the health effects of lie-ins on non-working days is mixed. Other studies have looked at the health effects of something called ‘social jetlag’ where a person’s natural body clock is out of sync with their sleep timings, because they do shift work and sleep for more hours on their days off than their work days.

A study published in 2015 in the Journal of Clinical Endocrinology and Metabolism of 447 healthy, working adults over 7 days found that those who slept over an hour later on their days off, compared to their working days, had a higher body mass index (BMI) and lower levels of ‘good’ cholesterol than those who slept less than an hour later.

However, the findings from this new, larger study may show that sleeping later during days off at the weekend to catch up on missed sleep in the week could outweigh the potential risks of a disrupted sleep schedule.

This suggests more research is needed on how sleep is linked to the risk of heart and circulatory diseases.

How good was the research?

The study has only been presented at the ESC Congress and is yet to be published in full in a medical journal. This means it has not been carefully checked by other researchers – a process called peer-review which is carried out by all respected journals.

Only the abstract (a short summary of the study) and a press release describing the study, were published on the ESC Congress website. This means we do not have all the information required to know how accurate the research is.

What we do know is that the data on the participants’ sleep was recorded with a device that measures movement called an accelerometer – meaning it should be accurate, rather than relying on participants to report their own sleeping habits. The study was also large, including more than 90,000 people.

But, while most of the media focused on ‘lie-ins’ we do not actually know how many people slept longer in the morning, caught up on sleep by napping over the weekend, or went to sleep earlier. 

And we do not know if participants worked Monday to Friday, with weekends off, or if some worked night shifts that meant they slept in the day rather than at night, which research has shown can affect the risk of heart disease.

For example, a study published in the European Heart Journal in 2021 of almost 300,000 people that also used data from the UK Biobank study found that those currently working permanent night shifts had a 12 per cent increased risk of atrial fibrillation than people who worked during the day, even after adjusting for other risk factors such as excess weight, high blood pressure and high cholesterol levels.

We do not know either if the researchers included, or excluded, people who already had heart and circulatory diseases, or were at risk of them, at the start of the study. The researchers also relied on participants’ own reports as to whether they got less than 7 hours of sleep a night in the week to find out how many were classed as ‘sleep deprived’.

Finally, being an observational study, it does not prove that extra sleep on the weekends directly lowers your risk of heart and circulatory disease, as other factors may be involved.

The BHF verdict

Commenting on the findings, Professor James Leiper, Associate Medical Director at British Heart Foundation, said: “Lots of us do not get enough sleep due to work or family commitments, and while a weekend lie-in is no replacement for a regular good night's rest, this large study suggests that it might help reduce risk of heart disease.” 

“We know that lack of sleep can affect our overall wellbeing, and this research is an important reminder of how important it is to try get at least 7 hours sleep every night."

“We look forward to future studies to better understand how sleep patterns can impact the heart and how we can adapt modern lifestyles to help improve our health.”

If you find it hard to get enough rest, sticking to a bedroom routine, getting outside during the day and practising relaxation techniques can help you sleep better throughout the week.

Content sourced from the British Heart Foundation (bhf.org.uk).