Here’s your new study routine: Hit the books. Wait a little while. Then, hit the gym.
New research suggests that physical exercise can help people retain information if it happens at the right time -- namely, a few hours after you learn the info, when new memories are getting stabilized in your brain.
The study's authors, who include researchers from Scotland's University of Edinburgh and the Netherlands' Radboud University, divided 72 people into groups and then had them all complete a memory task. Immediately afterward, one group of participants were asked to exercise on spinning bikes for half an hour. Another group were asked to wait four hours and then exercise. A third group weren't asked to exercise at all.
Two days later, the participants returned to the lab for a follow-up memory test. The people who'd waited four hours and then exercised performed about 10 percent better on this new test than people in the other groups.
The boost in memory was modest, but the findings offer initial evidence that properly timed physical exercise can improve memory retention, the researchers say. The exact time window for optimal results is not yet known. Although the study tested the effects of exercising after a four-hour delay, it's possible that waiting two hours or six hours to exercise could have a better (or worse) effect on memory.
Newly learned information creates memory traces in the brain, which can either decay or get consolidated into long-term memory. Recent studies have shown that physical exercise causes a sharp increase in the release of certain neurotransmitters, like dopamine and noradrenaline, that are likely crucial to the consolidation of memories. The researchers speculate this may be the reason why exercising helped the people in their study to retain information.
"These proteins help stabilizing new memory traces, which would otherwise be lost," Dr. Guillen Fernandez, a professor of cognitive neuroscience at the Radboud University Medical Center, told The Huffington Post in an email. "Physical exercise is at the start of this sequence, because it is accompanied by the release of dopamine and norepinephrine."
Fernandez said that high-intensity exercise is "likely necessary" to produce the memory-improving effects, and that "further studies are necessary to define the optimal delay in humans." In other words, it's possible that four hours is not the ideal amount of time to wait. Future research may help us zero in on a more precise answer.
The research appeared Thursday at the journal Current Biology.