All adults can prevent declines in episodic memory with regular exercise.

Researchers led by psychologists at the University of Pittsburgh investigated more than 1,279 studies, eventually narrowing them down to just 36 that met specific criteria which were then analysed.

The search was limited to particular groups and age brackets, as well as a specific kind of rigorous experimental setup.

They focused specifically on episodic memory, which is supported by a part of the brain that’s known to benefit from exercise.

Episodic memory deals with events that happened to a person in the past – and is one of the first to decline with age.

The results suggested that exercising around three times a week for at least four months reaps benefits.

Lead author Sarah Aghjayan said: “When we combined and merged all this data, it allowed us to examine almost 3,000 participants.

“Each individual study is very important: They all contribute to the science in a meaningful way.

“We found there were greater improvements in memory among those age 55 to 68 years, compared to those who are 69 to 85 years old — so intervening earlier is better."

"We also found the greatest effects of exercise in those who hadn’t yet experienced any cognitive decline, and in studies where participants exercised consistently several times a week."

The study – titled Aerobic exercise improves episodic memory in late adulthood: a systematic review and meta-analysis – was published in the journal ​​Communications Medicine. To access the study, ​​click here.