x
If you're trying to learn lines for your upcoming community theater production, you might be wise to take a break and hit the gym.
Previous research has shown that months of aerobic exercise, as well as single bouts, can improve memory. And a study published in 2014 found that just one short bout of strength training - in this case, leg lifts on a machine - can help you remember things.
The study enrolled 46 college students whose average age was about 20. However, says lead author and Georgia Tech grad student Lisa Weinberg, "we would predict a similar benefit in older adults. Other studies have looked at exercise effects in older adults and have found benefits."
The volunteers were shown a series of 90 photos on a computer screen but weren't asked to memorize them. A third of the images were positive (kids on a waterslide), a third were negative (mutilated bodies) and a third were neutral (a wall clock).
The volunteers then sat at a leg-extension resistance exercise machine. Half of them extended and contracted each leg 50 times, while the other half just sat there and let the machine and a researcher move their legs. While the volunteers sat on the machine, researchers monitored their heart rate and blood pressure and took saliva samples to check for levels of chemicals related to stress. Based on animal research, the scientists suspected that the physical stress of exercise would enhance memory.
The students returned to the lab 48 hours later and were shown 180 photos - the 90 they'd seen previously mixed in with 90 new ones. The volunteers who'd exercised remembered about 60 percent of the original 90 photos, while those who let the machine and a researcher move their legs remembered 50 percent.
People in both groups remembered the positive and negative photos better than the neutral ones. "We think this is because the hormones released [when exercising] affect areas of the brain involved in emotional memory," Weinberg says.
Even without a fancy machine or an extremely fit body, exercise can help you retain information, Weinberg says. But "exercising before learning new information," she cautions, "may not have the same effect."
Researchers aren't sure how exercise affects the brain's ability to learn and remember, but they have some ideas. "We argue that a single episode of exercise is similar to an experience like having to give a public speech, which most of us find stressful," says Audrey Duarte, an associate professor in Georgia Tech's School of Psychology and director of the lab where the work was done.
Although long-term stress can be bad for your health, she says, short periods of stress have been shown to improve memory retention through the release of stress hormones such as cortisol and epinephrine. "Physical exercise can trigger the release of these same hormones and, we think, improve memory," Duarte says.
Similar studies have shown that aerobic exercise, such as running and cycling, is helpful in boosting memory, but vigorous activities aren't for everyone. In this study, the level of resistance on the machine was set according to what each participant could handle.
"We wanted to use resistance exercise," Duarte says, "because we think that more people with a variety of physical abilities should be able to do this rather than, say, run.
