It is a common belief that stress negatively effects memory. This article suggests that not only does stress negatively effect memory, but exercise may actually assist memory both while stressed and while not stressed. A relatively new study has found that exercise has counteracted the negative effects of stress in mice.
Memories are coded and stored in the hippocampus allowing them to be recalled at later times. However, memories are very complex things that are stored in many different locations and across many brain cells. The stronger the connection between brain cells, the better and more permanent the memory is. Negative parts of our lives such as lack of sleep, alcohol use, and stress lessen the amount of communication between brain cells and weaken the memory.
However, exercise has been shown to improve both memory and learning abilities. Few to no studies before this one have looked at both the effects of stress and exercise on memory.
The study was run at Brigham Young University in Utah. The participants in the study were healthy male mice with the hopes to later look at the same effects on healthy female mice. The mice were divided into groups, one group continuing their normal lives, another group began to voluntarily run on their wheels running up to three miles a day!!! After the animals were around for about a month, some of the mice living their normal lives were put through three days of stressful activities. Some of the active mice were also put through three days of stressful activities. The three days of stressful activities were supposed to simulate chronic stress such as humans deal with commonly. The mice were then supposed to learn a maze with a treat in one of the corners. The researchers then looked at the synapses of the mice. They were able to stimulate isolated cells and see what type of and how many messages jumped between synapses.
The three days of stress weakened the synapses in the stressed out regular mice versus the control mice. The unstressed runners had the strongest synapses with the most activity suggesting that they were the most likely to learn and remember new things. Most importantly, the mice that were stressed and exercised has synapses that looked very similar to the mice from the normal unstressed control group. These mice synapses were not as strong as the exercising mice with no stress but much stronger than the animals that had not exercised and been stressed. The mice that exercised learned what corner the treat was in much faster and more consistently than the mice that had been stressed.
It is not completely known why or how exercise positively effects the strength of synapses but it is thought to be more activity in the proteins in the brain changing the synapses and allowing more buffering of the negative stress effects. It is also not known if different kinds of exercise would have the same effects. There is always a possibility that the same results would not be shown in humans.
Personally, I have had experience with this while training my service dog, Rotary. When he is active and has exercised he is much more likely to listen and learn new commands rather than if he has had a lazy day and not exercised. Again, I am not sure if the effects are the same on humans and it could be a coincidence with Rotary, but I believe exercise helps our bodies in many more ways than just one!
P.S. Not sure why the image is sideways and wont let me rotate it but you get the point 🙂