Exercise and the brain

(Picture from http://well.blogs.nytimes.com/2011/11/30/how-exercise-benefits-the-brain/?ref=health)

Many people believe that exercise increases brain function—especially memory. Several studies have focused on how exercise affects the brain. Recently, a study in Ireland tested a group of sedentary male college students (Reynolds). First the students watched a lineup of photos with faces and names of strangers and tried to recall all of the names they had just seen. Next, the groups were divided into two—one group rode a stationary bicycle at an intense pace and the other group sat quietly. Then, both groups took the memory test again. The results demonstrated that the exercised males performed significantly better on the test than they had on their first try, while the rested students did not improve their test scores (Reynolds).  

Importantly, blood samples were taken during the experiment which provided a biological explanation for the improvement in the memory test by the exercised subjects (Reynolds). Immediately after the exercise, the exercised students demonstrated higher levels of a protein known as brain-derived neurotrophic factor (BDNF). The men who remained seated throughout the experiment reported no change in the BDNF levels. BDNF is known to promote the health of nerve cells (Reynolds). Thus, the result of this study suggests that increases in BDNF provided by exercise may play a major role in improving memory and recall (Reynolds). Although, researchers have not fully understood which parts of the brain are affected.

Many other studies have used laboratory animals to tests the effects of exercise on the brain and it is well established that physical exercise can enhance hippocampal-dependent forms of learning and memory in these tested animals (Hopkins, Nitecki, & Bucci, 84). For examples, rodents have been studied demonstrating that wheel running or treadmill exercise improves spatial learning and contextual fear memory (Hopkins, Nitecki, & Bucci, 84). These effects were likely related to exercise-induced changes in hippocampal neural plasticity which includes increased neurogenesis, long-term potentiation, and enhanced expression of BDNF (Hopkins, Nitecki, & Bucci, 84).

Another comparable study was presented by Dr. Peter J. Clark on November 7, 2011, at Regis University—ShannonQ436 also blogged about his presentation. He studied mice that exercised on running wheels and demonstrated hippocampal neurogenesis in the inner layer of the dentate gyrus (Clark). His group of researchers tested these mice in cognitive tests and their results suggested that the exercise that stimulated the formation of new neurons in the hippocampus enhanced memory (Clark). 

Overall, a significant amount of research has reported that physical exercise induces specific changes in neural function and enhances learning and memory (Hopkins, Nitecki, & Bucci, 84). This is a very important area of research because the benefit of exercise on the brain is not fully understood. With the supporting studies, researchers suggest that exercise does increase memory and learning abilities. Thus, with finals quickly approaching—we should all take some study breaks and exercise!

Clark, P.J., Brzezinska, W.J., Puchalski, E.K., Krone, D.A., & Rhodes, J.S. (2009). Functional Analysis of Neurovascular Adaptations to Exercise in the Dentate Gyrus of Young Adult Mice Associated With Cognitive Gain. Hippocampus, 19(10), 937-950.

Hopkins, M.E., R. Nitecki, and D.J. Bucci. Physical exercise during adolescence versus adulthood: differential effects on object recognition memory and brain-derived neurotrophic factor levels. Neuroscience, 194: 84-94, 27 October 2011. Retrieved from http://www.sciencedirect.com.dml.regis.edu/science/article/pii/S0306452211009158.

Reynolds, Gretchen. How exercise benefits the brain. Well, November 30, 2011. Found at New York Times website. http://well.blogs.nytimes.com/2011/11/30/how-exercise-benefits-the-brain/?ref=health.