Effect of Physical Exercise on Sleep and Memory

Effect of Physical Exercise on Sleep and Memory

Memory is the ability to recall and remember information that has been learned and stored. Memory can be classified as short or long term. There are many factors that influence a person's memory skills, from psychological to environmental. These factors can have a direct or indirect influence on memory. For undergraduate college students, it is important to have sufficient memory skills to perform at expected levels. As undergraduate students, we wanted to see what factors influence memory skills to better improve it.

Sleep and Memory

Sleep is an important factor in improving memory. Sleep is an activity that is a natural part of life during which a person's body rests emotionally and physically. Evidence has shown that sleep has a positive, direct effect on memory; the more sleep a person has, the better their memory skills will be. In a study by Schlaug and his colleagues (2005), they came to the conclusion that certain areas of the brain that are involved in memory are more active after a period of sleep.

Mograss, Guillem and Godbout (2008) ran a study to test the relationship between sleep and short and long term memory. They had participants follow a strict sleeping schedule and gave them various memory tests; some of the memory tests were given the same day as the data presented and some were given a few days after to test short and long term memory. They came to the conclusion that more quality sleep improves memory. In an additional study done by Dolan and his team (2009), they used the Epworth Sleepiness Scale to assess how sleep affects people's lives on a daily basis. They gave each participant a questionnaire that they completed three times a day to see how sleepy they felt and how it was affecting their daily lives. Their results represented that the sleepier that people were, the worse they performed on daily tasks. These two studies indicate that memory is improved by periods of sleep.

Physical Activity and Memory

Another factor that improves memory is physical activity. Physical activity is any movement of the body that uses energy. This can be a variety of activities such as running, playing sports or taking walks. Evidence indicates that physical activity has a positive has a positive effect on memory; the more physically active a person is, the greater their memory skills will be.

Bugg and Clegg (2006) ran a study to see how physical activity affected memory at various times of the day. They gathered a group of physically active people and a group of non-active people and presented them with several memory tests at different times of the day. Their results indicated that those participants who were physically active had a higher, more constant memory capability at all times of the day, while those who were non-active scored significantly lower and their scores declined as the day went on. This study indicates that being physically active does have a positive effect on memory.

Physical Activity, Sleep and Memory

Previous research indicated that physical activity affects memory and sleep. Evidence suggested that the more physically active an individual is the better sleep quality they will have. Ultimately, since sleep quality will be improved by physical activity, it ultimately improves memory. Brand and his team (2009) examined how physical activity affects different psychological functions, including sleep. In order to see how physical activity affects these psychological functions, his team focused on athletes and non-athletes. After studying 434 adolescents, they came to the conclusion that exercise is positively related to sleep and other psychological functions. Another study by Newson and Kemps (2008) examined the relationship between fitness, sleep and cognitive performances. They surveyed 96 young adults, half of who were physically active and half who were not, with 17 assessments to see what kind of a relationship existed between the three variables. Their results represented that there was a positive correlation between physical activity and sleep and also between sleep and cognitive performances. Lopez (2008) was another researcher whose work we found that focused on all three constructs in a previous study. She developed a study that focused on the existence of a relationship between sleepiness, memory and physical activity through a series of questionnaires. She came to the conclusion that were in fact correlations between all three constructs; there was a positive correlation between physical activity and memory and a negative correlation between sleepiness and memory. These studies concluded that physical activity and sleep improve memory

Current Study

The present study was designed to examine the effects that the two constructs, sleep and physical activity, have on short-term memory. Previous studies indicated that sleep and physical activity improve memory and we wanted to see how this affects to the undergraduate population.

In the present study, we chose to build off of Lopez's research and further explore the relationships between the three constructs: memory, sleep and physical activity. Our hypothesis is composed of one indirect and two direct relationships. Sleep (construct 1) has a positive direct effect on memory (construct 2). Sleep is directly affected by physical exercise (construct 3) in a positive manner. Memory is then indirectly affected by physical exercise because of its positive influence on sleep, which positively affects memory. To test the hypothesis, we measured sleep with the Epworth Sleepiness Scale, physical activity with the Physical Activity Rating Questionnaire and an open-ended question and memory with how well a participant was able to memorize and complete a list of analogies.

Methods

Participants

The participants in our study included 22 male and 27 female volunteer undergraduate students from Dominican University. The selection process for this study involved recruiting students around campus that were either in introductory psychology classes or available around campus. Extra credit was offered to those participants whose teachers granted them the opportunity to receive extra credit from participating in our study. All of the participants who participated in our study were ages 18 to 29, and were mainly sophomores. The participants in our study were Hispanic, African American, Caucasian, or selected other; however the samples were mainly Caucasians and Hispanics. All participants were treated in accordance with the ethical guidelines of the Institutional Review Board (IRB) here at Dominican University.