At college exercise can either be at the front of your mind or the last thing you want to worry about. It’s understandable for those who don’t have time to exercise as often as they want to- classes, homework, and studying come first. But what if exercising actually helped your grades improve? I set out to find out, as I am not the person you see running to the gym every day.
My null hypothesis would be: Exercising often during the week does not affect grades at all. My alternative hypothesis would be: Exercising often during week affects grades positively.
I began my quest by checking out a few studies. What did they say?
The first study I looked at was done by Saginaw Valley State University, in which they looked at the grades and exercise habits of 266 students. They found that those who regularly exercised had higher GPA’s than those who didn’t. They, were, however a little skeptical on whether or not exercise was actually a cause of the effect of GPA. Was the exercise actually helping, or were those that did well in school just more likely to go to the gym more or keep a strict exercise regime? To combat that idea, they controlled variables such as grade point average, gender, how often people studied and even if they participated in college sports. With the controls, the conclusion still came out that those who exercised everyday had a .4 better GPA than the people who didn’t exercise.
When I looked at other studies, the results were also the same. In a study that looked at 259 3rd through 5th graders, a positive correlation was found between exercise and good grades. In a brand new study, it was found that university students that exercised for at least 20 minutes for most of the week had average grades that were 10% higher than those who didn’t exercise. Another study at Purdue also saw that out of the 1,820 students that went to the gym, those who went to the gym the most had the highest average GPA.
Curious to how exercise could possibly help improve grades, I looked at the benefits of exercise. Exercise helps increase oxygen flow to the brain (lack of oxygen lowers concentration), increase the amount of neurotransmitters, and believe it or not, can actually grow brain cells in the hippocampus, which is responsible for memory. Human studies are showing that cardio multiple times a week can lead to the production of up to 30% more cells in the hippocampus, leading to better memory (and therefore, better grades!).
This information almost had me convinced that exercise could in fact improve grades, and that this positive correlation was not due to a confounding variable such as work ethic, which was earlier discussed. But when I looked a little deeper, I found a study that showed that students that studied more than 3 hours a day were almost 4 times more likely to be involved in vigorous exercise than those who studied less than an hour a day. Also, students with GPA’s higher than 3.5 were 3 times more likely to participate in vigorous exercise than those who had under a 3.0 GPA.
So which is true? We know that the more exercise a person does, the more likely they are to have better grades, but why? Does exercise itself lead to better grades, or are they just connected through the great work ethic of individuals?
The only way to find out is to do an experiment, instead of a correlational study like those referenced above. An appropriate experiment would be to take students with a plethora of different GPAs that reported that they DO NOT currently work out and separate them in half. Half would be required to exercise at least 4 times out of the week for at least 20 minutes (and monitored to make sure that they do!). The other half would be the control group, and would continue on with their daily lives not working out (and they are not allowed to start working out). We would then compare each group’s new GPA with their previous GPA. If the experimental group had a higher improvement in GPA than those in the control group, it would evident that the physical benefits of exercise actually help increase your grades.
While we can’t actually do this experiment, we were still able to refute the null hypothesis and be fairly confident about the positive correlation of exercise and grades. So if you’re not exercising, I would go ahead and give it a try!