You’ve just gotten back from an hour long workout at the gym and feel great. Your muscles are a little sore, and you are tired out but energized at the same time, and your mood has brightened up a few notches.
The findings, from a study at the Radboud University Medical Center in the Netherlands, show that physical exercise after learning boosts memory and memory traces. But the results, the researchers say, apply only if the exercise is done in a specific time window and not immediately after learning.
“It shows that we can improve memory consolidation by doing sports after learning,"
says Guillén Fernández of Radboud University Medical Center’s Donders Institute. Fernández, along with Eelco van Dongen and their colleagues, tested the effects of a single session of physical exercise after learning on memory consolidation and long-term memory.
Seventy-two study participants were involved. They learned 90 picture-location associations over a period of approximately 40 minutes before being randomly assigned to one of three groups.
One group performed exercise immediately, the second performed exercise four hours later, and the third did not perform any exercise.
35 minutes of interval training on an exercise bike at an intensity of up to 80 percent of participants' maximum heart rates.
Forty-eight hours later, participants returned for a test to show how much they remembered while their brains were imaged via magnetic resonance imaging (MRI).
Two days later, those who exercised four hours after their learning session retained the information better than those who exercised either immediately or not at all. The brain images also showed that exercise after a time delay was associated with more precise representations in the hippocampus, an area important to learning and memory, when an individual answered a question correctly.
“Our results suggest that appropriately timed physical exercise can improve long-term memory and highlight the potential of exercise as an intervention in educational and clinical settings,” the researchers conclude.
As yet it is unclear exactly how or why delayed exercise would have such an effect on memory. But earlier studies of laboratory animals suggest that neurotransmitters, including dopamine and norepinephrine, can improve memory consolidation, the researchers say.
And it just so happens that one way to boost those neurotransmitters is through physical exercise.
Eelco V. van Dongen, et al Physical Exercise Performed Four Hours after Learning Improves Memory Retention and Increases Hippocampal Pattern Similarity during Retrieval Current Biology; DOI: http://dx.doi.org/10.1016/j.cub.2016.04.071