Exercising four hours after learning something may help you remember it better, reported a Dutch study in Current Biology, in which 72 people studied 90 picture-location associations over 40 minutes and then exercised immediately after (35 minutes of interval training), exercised 4 hours later, or did not exercise at all. Two days later, those in the delayed-exercise group remembered significantly more of the associations on a recall test than the immediate-exercise and no-exercise groups, with no differences between those groups.
Lab research has shown that exercise triggers the release of brain chemicals that may promote memory consolidation but, as the researchers speculated, immediate exercise did not provide a memory boost because “the neural context at this time was already optimal following initial learning and recall and could not be further improved through an additional influx of consolidation-promoting factors.”
The study did not, however, determine the optimal time window for the exercise (it’s possible that waiting a longer or shorter time before exercising would improve results as much or even more) and whether the effect varies depending on the type of memory task.
Also see How Exercise Boosts Your Brain.