In the study, published in the journal Neurobiology of Learning and Memory, researchers found running prevents stress from wreaking havoc on your brain—particularly on the part tasked with learning and memory.
Researchers conducted the experiment on mice. One group was encouraged to run on a wheel during a four-week period, averaging about three miles per day (pretty good for rodents). The other group of mice was sedentary. Half of each group was then introduced to stressful situations, like walking on a raised platform and swimming in cold water.
Researchers measured the mice's brains one hour after they induced stress to measure long-term potentiation, aka LTP—a process during which the connections between neurons are strengthened over time in the hippocampus. This is how memories are formed and recall occurs.
Over time, chronic stress weakens this connection between neurons. But the stressed mice that ran had significantly greater LTP than the ones that didn't stride in their wheels. What's more, exercise proved beneficial to memory regardless of stress levels. Stressed mice that exercised performed just as well as nonstressed mice who exercised on a maze-running experiment. Researchers theorize running reduces the impact stress has on the hippocampus.
"The ideal situation for improving learning and memory would be to experience no stress and to exercise," lead study author Jeff Edwards said in a press release. "Of course, we can't always control stress in our lives, but we can control how much we exercise. It's empowering to know that we can combat the negative impacts of stress on our brains just by getting out and running."