Physical activity has a significant effect on brain health, and it can not only rejuvenate your brain but also prevent or delay cognitive decline that comes with ageing, according to a new study on 15 May.

A team from the University of Queensland in Australia focussed on the expression of genes in individual cells in the brains of experimental models.

The results, published in the journal Aging Cell, showed that exercise has a significant impact on gene expression in microglia -- the immune cells of the central nervous system that support brain function.

Importantly, the team found that exercise reverts the gene expression patterns of aged microglia to those seen in a young experimental model.

"We were both surprised and excited about the extent to which physical activity rejuvenates and transforms the composition of immune cells within the brain, in particular the way in which it was able to reverse the negative impacts of ageing," said Jana Vukovic, from the University of Queensland.

Vukovic noted that the study stresses the importance of "tailored exercise programmes".

"Our findings should help different industries to design interventions for elderly individuals who are looking to maintain or improve both their physical and mental capabilities," she said.

Further, the study showed that running on a wheel "prevented and/or reduced the presence of T cells in the hippocampus" in the experimental model during ageing.

T-cells are immune cells known to increase with age. They found that microglia cells are required for the stimulatory effects of exercise to help form new neurons in the brain’s hippocampus -- a region involved in memory, learning, and emotion.

The study can help design interventions for older adults to maintain or improve both physical and mental health.