Academia and sports haven't always been the most comfortable of bedfellows — but it turns out they might be more compatible than you think. A new Dutch study suggests a good way to reinforce what you've just learned is to hit the gym four hours later.
The findings show that physical exercise improves memory but only if it's done within a specific, postponed time window rather than immediately after learning. Guillén Fernández and his colleagues at the Donders Institute at Radboud University Medical Center in the Netherlands tested the effects on memory consolidation and long-term memory of a single session of physical exercise after learning.
Seventy-two study participants learned 90 picture-location associations throughout a period of approximately 40 minutes before being randomly assigned to one of three groups. The first group performed exercise immediately, the second worked out four hours later and the third were given no exercise at all. The sessions consisted of 35 minutes of interval training on an exercise bike at an intensity of up to 80% of participants' maximum heart rates. Forty-eight hours later, participants returned for a test to show how much they remembered. During testing the researchers scanned participants’ brains with magnetic resonance imaging (MRI).
The researchers found that those who exercised four hours after their learning session had, two days later, retained information better than those who exercised either immediately after learning or not at all. Brain scans also showed that exercise after a time delay was associated with more precise representations in the hippocampus — an area of the brain important for learning and memory — when an individual answered a question correctly.
The scientists say it's not exactly clear how or why delayed exercise has this effect on memory. However, previous studies of laboratory animals suggest that naturally occurring chemical compounds in the body known as catecholamines can improve memory consolidation, the researchers say. One known way to boost catecholamines is through physical exercise.
Fernández says they will now use similar experiments to study the timing and other details of exercise and its influence on learning and memory. According to the researchers, the study — reported in the journal Current Biology — is encouraging. "It shows that we can improve memory consolidation by doing sports after learning," says Fernández.
"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.