Sleeping an extra hour or two on the weekends can reduce the risk of high blood pressure, a study shows.
Scientists have largely asserted that people should keep regular bedtimes and wake-up times, maintaining a consistent sleep schedule across the week, including weekends.
But the new study questions that view, building on other recent research that suggests weekend lie-ins – and extra sleep more broadly – are good for the heart and overall health.
What does the latest study say?
The findings, presented on Sunday at the European Society of Cardiology’s annual congress in Munich, Germany, were based on a seven‑year study of ۴۰,۷۲۷ adults in South Korea. These were adults from the Korea National Health and Nutrition Examination Survey, studied from ۲۰۱۶ to ۲۰۲۳.
The researchers examined how many extra hours participants slept at weekends compared with weekdays.
The latest study found that catching up on sleep at the weekend after a long workweek lowers the prevalence of high blood pressure.
However, this was only the case when lie-ins were kept at a moderate length – about one to two hours of extra sleep with an optimal increase of about one hour and ۳۷ minutes.
In all, weekend catch-up sleep was associated with a ۶ percent decrease in the chances of high blood pressure. This decrease was larger for physically inactive people, who saw a ۶.۹ percent decrease in chances of hypertension. The study found that someone getting one hour and ۳۷ minutes of extra sleep at weekends could reduce their chances of hypertension by ۹ percent.
As of ۲۰۲۴, ۱.۴ billion adults aged ۳۰-۷۹ worldwide have hypertension, accounting for ۳۳ percent of the world population in this age range, according to the World Health Organization. High blood pressure is a major cause of premature death worldwide, the United Nations agency added.
The findings of this study have not yet been published in a peer-reviewed journal.
The author of the study, Nawon Lee from Korea University in Seoul, said in remarks reported by several news outlets on Monday that not sleeping enough places extra stress on the body, forcing the heart and blood vessels to work harder, which can increase blood pressure.
She added that people should not feel lazy or guilty for sleeping a little longer at the weekend if they have not been able to get enough sleep during the week. Sleeping in during the weekend could be the body’s way of recovering from that sleep loss.
However, she warned that when weekend catch-up sleep becomes excessive, the degree of sleep irregularity and circadian disruption may increase, which could offset that benefit.
Do other studies support similar claims?
In the ۲۰۲۴ European Society of Cardiology’s annual congress in London, researchers presented a study of more than ۹۰,۰۰۰ individuals.
The study found that people with the most weekend catch-up sleep had about a ۲۰ percent lower risk of developing heart disease than those with the least.
A large body of modern medical research supports a strong association between adequate sleep and better heart health.
What does the broader science say about sleep?
For decades, the medical consensus has been that too little sleep can harm cardiovascular health, that seven to nine hours a night is generally optimal for adults and regularly sleeping much more than that may sometimes point to an underlying health problem.
However, scientists have previously suggested that weekend lie-ins could be harmful by disrupting the body’s natural circadian rhythm, a built-in biological clock running on an approximately ۲۴-hour cycle that regulates sleep, hormone release and body temperature.
In ۲۰۱۹, researchers studied ۳۶ adults, dividing them into three groups. One group had their sleep restricted to five hours a night over nine nights, including weekends, another was restricted to five hours a night but was allowed to catch up unrestricted at weekends and one group was allowed nine hours of sleep over nine nights.
Both the groups with restricted sleep snacked more in the evening and saw a decline in metabolic health. The study found that the people who slept more at the weekend partly improved while they were actually sleeping more.
However, once they went back to short sleep, the benefits disappeared and overall metabolic health was still worse than in people who consistently slept more every night.
