A well-timed workout can boost your long-term memory, a new study suggests.
Researchers from the Netherlands and Scotland found doing aerobic exercise four hours after committing something to memory improves how well it sticks – but exercising immediately afterwards or not exercising at all makes no difference.
Earlier studies on animals show brain chemicals such as dopamine and noradrenaline, released during exercise, can help improve memory.
So Guillén Fernández from Radboud University in the Netherlands and colleagues decided to test the link between exercise and memory in humans.
Their subjects – 72 people split into three groups – each sat through a task to try to memorise 90 pictures in 40 minutes.
One group then exercised for 35 minutes immediately afterwards at high intensity, a second group exercised after four hours of sitting in a quiet room, and a third didn’t exercise at all.
Two days later each group were called back in to recall the pictures.
The delayed exercise group scoring significantly higher than the others, and well above the level that would be explained by chance.
So what’s going on?
Building long-term memory relies on making new communications between brain cells. This process, neuroplasticity, is modulated by chemicals such as dopamine and noradrenaline.
But if the chemicals aren’t released at the right time, our memories decay.
Fernández says four hours may not even be the optimal time to exercise following a memorisation exercise: “It might also be even better after two hours or one hour.”
As yet, it isn’t entirely clear why delayed exercise, rather than immediate exercise, improves long-term memory.
One theory is straight after learning, dopamine and noradrenaline levels are high in the brain. But after a few hours, they drop.
Intense exercise is like a booster to keep the memory consolidation process ticking along, and the researchers plan to explore this down the track.
For now, though, “the take-home message is there is a window of opportunity after learning that is a few hours long where these processes can be modulated”, Fernández says.
The findings were published in the journal Current Biology.