Cramming your exercise into the weekend not only brings physical benefits on a par with regular workouts, but is just as good for your brain, a study suggests.

Research has previously revealed that physical exercise is associated with better brain health and lower risk of dementia in older age.

Now a study of more than 10,000 people has found that both “weekend warriors” – people who exercised just once or twice a week – and those who undertook more regular physical activity showed reductions in the risk of mild dementia compared with inactive individuals.

“I think our study is more good news for busy people around the world,” said Dr Gary O’Donovan. “This is our latest weekend warrior study, and it’s now becoming increasingly clear that the benefits of exercising once or twice a week are much the same as exercising more often.”

The “weekend warrior” pattern of physical activity has become a popular topic of research. Among other work, a study led by Dr Shaan Khurshid of Massachusetts general hospital in Boston found those who fit a week’s worth of exercise into one or two days have a lower risk of developing more than 200 diseases compared with inactive people, with regular exercisers experiencing similar benefits.

Research suggests intermittent exercise could also bring benefits for the brain.

“This is the first longitudinal study shows that the weekend warrior physical activity pattern is also good for mental health,” O’Donovan said.

Writing in the British Journal of Sports Medicine, O’Donovan and colleagues report how they analysed data from the Mexico City Prospective Study, a research endeavour in which individuals aged 35 and older were surveyed for the first time between 1998 and 2004, and for a second time between 2015 and 2019.

The results from the first survey revealed that, out of 10,033 participants, 79.2% reported undertaking no sport or exercise, 7.2% were “weekend warriors” who reported exercising once or twice a week, and 13.6% exercised more regularly.

In the second survey, participants were screened for cognitive impairment and dementia. The results reveal 26% of those who reported no sport or exercise in the first survey met the criteria for mild dementia when the traditional threshold was used, compared with 14% of weekend warriors and 18.5% of the regularly active group.

A further analysis, taking into account factors such as age, sex, education, income, smoking, and body mass index, found the weekend warrior group had a 25% lower risk of mild dementia compared with the inactive group, while the regularly active group had an 11% lower risk.

The team estimated 13% of mild dementia cases would be eliminated if all middle-aged adults were to take part in sport or exercise at least once or twice a week.

While O’Donovan said it was not clear why the weekend warrior group had a lower risk of mild dementia than those who undertook more regular exercise, he said it could be down to the nature of the screening tool, stressing it was not a clinical diagnosis. The team noted the two active groups showed similar sized reductions in risk relative to the inactive group when a different threshold for the screening tool was used.

Khurshid, who was not involved in the study, welcomed the research noting that while it relied on self-reported exercise that can be subject to error, it supported the idea individuals should get their physical activity in a way that works for them.

“It adds to the growing body of evidence that concentrated physical activity is associated with beneficial health outcomes, and in this case, adds cognitive impairment to the list,” he said.

Indeed, Khurshid said previous work had emphasised it was the total volume of exercise, rather than the pattern, that mattered most for disease risk.

“So you need to exercise longer on those fewer sessions per week if you’re going to be a weekend warrior, so that you’re still getting the recommended activity volumes,” he said.