Tag Archives: neuroscience

Working Out the Body for the Mind

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In high school, I led an extremely active lifestyle. I ran cross-country, indoor and outdoor track, and had two training sessions daily, Monday through Friday. However, when I came to college, I wasn’t able to maintain as rigorous of a workout routine as I had before because of the increase of workload and scheduling differences. But now I feel as if the decrease in exercise in my life has affected other aspects such as mood, energy, and even school performance. In high school, I would wake up everyday at 6 am to go to school and have practice ranging anywhere from 2-4 hours, go to sleep at 11 or 12 and still get enough sleep and maintain a competitive GPA. Now I work out about 3 to 4 time a week for an hour or so, but I feel sluggish and tired throughout the day and it takes me a bit more effort to understand and comprehend my work. My eating and sleeping habits have only changed marginally since I came to college so I am really interested to find the answer to my question, “Does exercise have a positive affect on my academic performance?”

After I did some digging, I found an article on the New York Times back from 2012. Researchers in the department of psychology and neuroscience at Dartmouth College conducted an experimental study on 54 adults, ages 18 to 36, who were healthy but generally sedentary (meaning none of them exercise regularly). I believed that this was a good range for what I was personally looking for, but the only hesitation I had was that these participants were volunteers, which could lead to voluntary response bias. I know we did not go over this specific bias in class, but the idea is pretty much straight forward—those who volunteer to take part of something usually have prior believes or relations to the experiment, however, it mostly comes up in surveys and observational, so I did not worry myself too much about it.

The participants filled out a series of questionnaires about their health and mood, including how anxious they were both at that moment and in general. Previous studies have shown that exercise can increase levels of a protein called “brain-derived neurotropic factor (BDNF), which is thought to play a role in the positive effects of exercise on thinking. However, some people produce less BDNF by natural after exercise because of a variation in the gene that controls the production, so blood was draw from the participants for genetic testing to account for this.

The group also submitted a memory test that consisted of pictures of objects flashing across a computer screen in order to involve a different part of the brain that is normally focused on in studies of exercise and memories. This exercise involved the perirhinal cortex, a portion of the brain essential to remembering particular things and whether they happen to be new in your experience, rather than the hippocampus, the brain’s primary memory center. I really liked this distinction because I believe that is the part of the brain that is most used when learning new material in a classroom.

After all of the testing, the volunteers were randomly assigned to exercise or not over the time period of four weeks. Half began a supervised program of walking or jogging four times a week for at least 30 minutes, while the other half remained sedentary. The randomization at this point cleared up most of the doubts I was having before about the potential volunteer response bias.

At the end of the month, the participants were brought back for final mood and memory testing, but before hand, half of each group (those who exercised for the month and those who did not) walked or jogged.

As expected, many of the volunteers who’d been exercising for the past month significantly improved their scores on the memory and mood tests. But not all of them did. In general, those volunteers who had exercised for the past month and who worked out on the day of retesting performed the best on the memory exam. They also tended to report less anxiety than other volunteers. Those who had exercised during the preceding month but not on the day of testing generally did better on the memory test than those who had been sedentary, but did not perform nearly as well as those who had worked out that morning.

I found these results very motivating. It showed me that not just working out periodically, but consistent exercise correlates to both memory retention and anxiety regulation. Since there is a time factor of this experiment, reverse causation isn’t a viable problem that the results may face. This experiment in my opinion was conducted extremely well, and very thorough in its research. From these results, I feel like it is a sensible idea for other people should strongly consider implementing some sort of consistent exercise in their schedule because it has the positive outcomes seem to out weight any of the hassles of getting it done. I appreciate that there are some people who just don’t enjoy the process of exercise, so my advice to them would maybe just to try to be more aware of how active you are throughout the day. Rather than taking the bus, leave a couple of minutes earlier to walk to class.

 

http://well.blogs.nytimes.com/2012/05/30/how-exercise-can-jog-the-memory/?_r=1

http://www.ncbi.nlm.nih.gov/pubmed?term=22554780