Researchers say exercising 4 hours after learning may improve memory recall.
Study co-author Guillén Fernández, of the Donders Institute at the Radboud University Medical Center in the Netherlands, and colleagues found that adults who exercised 4 hours after completing a learning task had better memory recall 2 days later.
However, exercising immediately after the learning task or not at all appeared to have no effect on memory retention.
The researchers recently published their findings in the journal Current Biology.
For the study, the team enrolled 72 individuals to complete a 40-minute task in which they were required to view 90 pictures and learn the associated locations.
The participants were then allocated to one of three groups: one group exercised immediately after the learning task, one group exercised 4 hours after the learning task, and one group did not exercise at all.
Both exercise groups completed 35 minutes of interval training using an ergometer.
Memory retention improved for delayed exercise group
All participants underwent a memory recall test 2 days later, which assessed how much information they retained from the learning task.
They also underwent functional magnetic resonance imaging (fMRI), which measured brain activity during memory recall.
Compared with participants who exercised immediately after the learning task or not at all, those who exercised 4 hours after were found to have better memory recall after 2 days.
Furthermore, the researchers found that when participants who exercised 4 hours after the learning task correctly recalled information, they had more precise representations of correct answers in the hippocampus - the brain region important for learning and memory.
Commenting on the possible implications of their findings, the authors say:
"[...] our results provide initial evidence that properly timed physical exercise can alter mnemonic processes at delayed retrieval and improve memory retention over a period of at least 48 hours.
The economic, healthy, and practical nature of exercise makes it ideal for interventions in educational and clinical settings. Our experiment thus serves as a proof-of-principle study that could inspire future applications of exercise to boost long-term memory in various populations."
While the authors are unable to explain exactly why delayed exercise appears to boost long-term memory, they point to animal studies that have shown exercise can increase levels of catecholamines, which are chemical compounds that can improve memory consolidation.
In future research, the team plans to investigate the underlying mechanisms by which delayed physical activity affects learning and memory.