Crosswords have long been heralded for their role in keeping ageing minds agile, but a mounting body of evidence suggests that CrossFit sessions may be an even better option.

New research published in the journal Plos One finds that older adults who regularly engage in moderate to vigorous physical activity have more variable brain activity at rest than those who don’t. This variability is associated with better cognitive performance, the researchers say.

The study comprised 100 adults between the ages of 60 and 80, with accelerometers used to objectively measure their physical activity over a week. The researchers used functional MRI to observe how blood oxygen levels changed in the brain over time, reflecting each participant’s brain activity at rest.

The researchers also evaluated the microscopic integrity of each person’s white-matter fibres, which carry nerve impulses and interconnect the brain. They found that, on average, older adults who were more active had better white-matter structure than their less-active peers.

“Our study, when viewed in the context of previous studies that have examined behavioural variability in cognitive tasks, suggests that more-fit older adults are more flexible, both cognitively and in terms of brain function, than their less-fit peers,” said Art Kramer – director of the Beckman Institute for Advanced Science and Technology – who led the study with University of Illinois postdoctoral researcher Agnieszka Burzynska.

The findings serve to further underline the importance of exercise in relation to ageing. They come just a month after researchers at the University of Kansas Medical Center (KUMC) found that raising fitness levels in later life can boost brain function. The research indicated that the intensity of the exercise appeared to matter more than the duration, backing up previous findings.