Theres lots of positive reasons to hit the gym, but did you know that lifting weights can improve your memory? A new study conducted by the Georgia Institute of Technology shows that intense workout of as little as 20 minutes can enhance episodic memory or long-term memory for previous events by about 10 percent in healthy, young adults.
Our study indicates that people dont have to dedicate large amounts of time to give their brain a boost, says Lisa Weinberg, project leader and Georgia Tech graduate.
The study published in the journal Acta Psychologica took a few new approaches in researching how exercise can improve memory. Participants lifted weights just once two days prior to testing and also studied events just before the exercise instead of just after. Although weight exercises were used for the study, resistance activities such as squats or knee bends would most likely produce the same results. The exercises did not require a person to be in good enough shape to run, bike or participate in prolonged aerobic exercise.
Extensive animal research in the past has suggested that the period after learning consolidation is when the arousal or stress caused by exercise is most likely to benefit memory.
The participants first looked at a series of 90 photos on a computer screen a combination of positive, negative and neutral images and were not asked to try to remember the photos. Next, they sat at a leg extension resistance exercise machine. Half of the participants extended and contracted each leg at their personal maximum effort 50 times. The control group just sat in a chair and allowed the experimenter to move their legs. Each participants blood pressure and heart rate were monitored and they also contributed saliva samples for the researchers to detect levels of neurotransmitter markers linked to stress.
Forty-eight hours later the participants returned to the lab and were shown 180 pictures a mixture of the first 90 photos and 90 new photos. While the control group recalled about 50 percent of the photos from the first session, those that exercised remembered about 60 percent. While all the participants remembered the positive and negative images better than the neutral ones, the pattern was greatest in the exercise participants with the highest physiological responses. This was expected though since existing research on memory indicates that people are more likely to remember emotional experiences especially after short-term stress.
This study found that exercise participants had increased saliva measures of alpha amylase, a marker of central norepinephrine. Existing research has linked memory enhancements to acute stress responses usually from psychological stressors such as public speaking. Other studies have tied specific hormonal and norepinephrine releases in rodent brains to better memory.
Now that the researchers know resistance exercise can enhance episodic memory in healthy, young adults, the researchers plan to expand the study in the future. The findings are encouraging because they are consistent with rodent literature that pinpoints exactly the parts of the brain that play a role in stress-induced memory benefits caused by exercise, said Audrey Duarte, associate professor in the School of Psychology. Even without doing expensive fMRI scans, our results give us an idea of what areas of the brain might be supporting these exercise-induced memory benefits.
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, added Minoru Shinohara, an associate professor in the School of Applied Physiology. This includes older adults and individuals with memory impairment.