Memory may be boosted by exercise, study finds

Sticking to a regular exercise regime could be enough to ward off some of the decline in memory often associated with ageing, according to new research.

A team led by Sarah Aghjayan at the University of Pittsburgh pooled together the results of 1,279 previous studies on how aerobic activity could affect mental agility. They then used dedicated computer software to turn the data into records that could be directly compared.

The researchers were aware that the limits of past work meant a link between memory and exercise had never been properly established. However, they felt that by utilising an entire body of studies and focusing on episodic memory in particular, they would have a better chance of seeing the bigger picture.

Exercise and episodic memory

Episodic memory deals with events that happened to a person in the past and is known to be one of the first things to begin to decline with age, but it has also been previously linked to having the potential to be boosted with exercise.

In this new study, it was found that aerobic activity did indeed benefit memory, with early intervention showing the best results (i.e. 55 to 68 years, rather than older) and those who had not yet demonstrated any cognitive decline enjoying the greatest effects.

Importantly, participants who consistently exercised were most likely to achieve significant benefits to their mental agility.

Writing in the journal Communications Medicine, Dr Aghjayan said: "It seems like exercising about three times a week for at least four months is how much you need to reap the benefits in episodic memory."

She added that exercise is an accessible way for older adults to improve their health, but pointed out that it doesn't need to involve vigorous aerobics or taking up marathons.

"You just need a good pair of walking shoes and you can get out there and move your body," Dr Aghjayan concluded.

Past links to movement and better brain power

A number of previous studies have also looked into the mechanisms through which exercise could boost brain power, with one at Goethe University Frankfurt in 2017 suggesting it may be down to physical activity limiting the production of a metabolite called choline.

This is known to increase with the loss of nerve cells that typically accompany Alzheimer's disease, so greater levels of movement may be having a protective effect on brain cells. 

Meanwhile, another at the University of British Columbia in 2014 found regular aerobic exercise appeared to boost the size of the hippocampus region of the brain that deals with verbal memory and learning.

Although standard recommendations are for 150 minutes of moderate physical activity a week, older adults with more limited mobility may therefore benefit from even just a few minutes a day of walking or other pursuits that get the blood pumping and flowing through the cells in the brain.