Building Muscle Boosts Memory

Individuals who completed strength training exercises improved their episodic memory when compared with those who did not exercise.

Strength training could be just as good for the mind as it is for the body, according to the results of a recent study.

Previous research has shown that aerobic exercise may improve episodic memory over time because it produces a physiological response similar to physical stressors. The current study, published in the November 2014 issue of Acta Psychologica, analyzed the effects of a single session of resistance exercise on emotional episodic memory just 48 hours after the activity.

For the study, a group of young adults viewed 90 photographs portraying negative or distressing scenes, such as mutilated bodies; positive images, such as children playing; or neutral images, such as a wall clock. The participants were then randomly assigned to either actively complete knee extension and flexion exercises or passively allow a machine to move their leg in the same motion. Physiological response to the exercise was measured by heart rate, blood pressure, and salivary amylase.

After 48 hours, the participants were shown the original images, as well as 90 new photos, and were then asked to identify whether they had seen the image before, whether it seemed familiar, or whether it was new.

The results indicated that those in the active exercise group accurately remembered more pictures than the passive control group. Individuals who exercised actively remembered approximately 60% of the photos, compared with 50% accuracy among the passive group.

Overall, participants were more likely to remember positive and negative images than neutral images, with no significant difference between negative and positive images. This effect was most prominent among those with the greatest physiological responses to the exercise, which impaired their memory of neutral images.

Among the active group, individuals with low physiological responses to the exercise displayed higher accuracy in recalling neutral images than those with high physiological responses. High and low responders in the active group had similar accuracy for negative and positive images.

“Our study indicates that people don’t have to dedicate large amounts of time to give their brain a boost,” said study author Lisa Weinberg in a press release.

The findings also indicated that older adults and those with conditions who cannot complete aerobic or strenuous exercise could still reap the memory benefits with moderate exercise.

“We can now try to determine its applicability to other types of memories and the optimal type and amount of resistance exercise in various populations,” said study author Minoru Shinohara, PhD, in the press release. “This includes older adults and individuals with memory impairment.”