Why To Exercise Today: A Better Memory (But Timing Is Key)

If you’re cramming for a test, the answer to a better memory may be less time with the flashcards and more time at the gym, according to a new study published by researchers at the Radboud University Medical Center in the Netherlands. But there's a twist: for the best results, waiting four hours before exercising is key, the study found.

The reason for this likely hinges on the importance of naturally occurring chemical compounds and hormones like noradrenaline and dopamine in the “encoding of memory,” researchers report.

If these factors are not released during the memorization process, memories will often decay, and never become entrenched in long-term memory. Previous studies have found that exercise increases the release of these key agents, researchers say, which may provide an all-natural boost to our long-term memory creation process.

In the new study that involved 72 participants, researchers found that people who performed 35 minutes of aerobic exercise four hours after memorizing 90 picture-location associations were better able to recall those associations 48 hours later.

While these findings may encourage you to hit the gym right away, further study suggests that the precise timing of the exercise is just as important as the workout itself. The four-hour delay of exercise is crucial, according to the study.

"We found that performing exercise 4 hours, but not immediately, after encoding improved the retention of picture-location associations compared with the control group,” study authors Guillén Fernández and Eelco van Dongen wrote in the journal Current Biology. “Our results suggest that appropriately timed physical exercise can improve long-term memory and highlight the potential of exercise as an intervention."

“One has to probe this issue systematically to define the optimal exercise delay, intensity and duration," added Fernández in a followup-interview via email. "Regardless, one can say that a four hour delay with a moderate to intensive physical exercise improves memory.”

How can you fit the right type of memory-boosting exercise into your day? The participants in the study performed 35 minutes of interval training on a stationary bike. If indoor biking isn’t for you, these effects can easily be replicated on road bike or just by hitting the roads for a quick run.

According to Fernández, it is likely substantial aerobic exercise that determines the release of these chemical compounds, although more studies will be required to verify this.

Still, Fernández said in response to a question, that many of the participants in the study believed that this type of exercise was feasible in their daily routines. He said that for the best results, "we think one requires moderate to intense exercise."