Attention gains persisted for a year

Participants in the exercise group did show greater improvements in attention at both six and 12 months. They also showed greater improvement in memory at six months, although that difference between groups was no longer evident at 12 months. The researchers found no significant differences in executive function.

"Attention is central to our everyday activities. It helps us follow conversations, absorb information and complete tasks without making errors, so the sustained improvements we saw in this trial are particularly encouraging," said Sheri Hartman, Ph.D., lead author of the study, professor at the UC San Diego Herbert Wertheim School of Public Health and Human Longevity Science and a member of Moores Cancer Center. "It is also encouraging that participants achieved this benefit with a modest, attainable increase in physical activity."

Slower aging in blood markers

The companion study followed a random subset of 124 participants who provided blood samples at the start of the study and at six- and 12-month follow-ups. The researchers used epigenetic clocks—tools that estimate a person's biological age from DNA methylation patterns, chemical modifications on DNA that change with age. Because these clocks measure biological markers rather than calendar years, a person's epigenetic age can differ substantially from their chronological age.

At the start of the study, participants in both groups had epigenetic ages averaging about 8.7 years older than their chronological ages. Over the 12 months, the health and wellness group showed nearly 10 months of epigenetic aging, while the exercise group showed only about one month.

The researchers also found that, across both groups, faster epigenetic aging tracked with less improvement in attention and worse self-reported cognition. This pattern suggests exercise may help buffer some of the cognitive effects associated with accelerated epigenetic aging.

"What is particularly striking about these findings is that the effects of exercise were measurable both at the molecular level and in cognitive performance," said Paula Desplats, professor of neurology at The Ohio State University, adjunct professor of neuroscience at UC San Diego School of Medicine and co-senior author of the companion study. "The changes we saw in markers of epigenetic aging suggest that even a relatively modest increase in physical activity may influence biological processes that help keep the brain healthy. This gives us an important clue about how exercise may help protect brain function after cancer treatment."

Questions about lasting benefits remain

The researchers caution that larger studies are needed to confirm the findings, to determine whether changes in epigenetic aging directly cause cognitive benefits, and to understand how exercise sustains improvements in attention and memory over time.

"Ultimately, we want to understand not just whether exercise helps, but who is most likely to benefit, how much activity is needed and what changes in the body might explain those benefits," Hartman said. "That knowledge could help us develop more targeted ways to support cognitive health after cancer treatment."