Table Of ContentImpact of Aerobic and Anaerobic Exercise on Short and Long Term Memory Retention
Jessica Hotter, Aaron Follansbee, Megha Patel, Zack Nigogosyan, Tal Zivan
Lab 601 Group 5, Physiology 435 Spring 2013
Objective: The aim of this study was to explore the relationship between memory retention and exercise. The hypothesis of this
study is that moderate aerobic and anaerobic exercise would improve memory retention.
Methods: Three different groups were analyzed: anaerobic, aerobic and control group. Measurements that were taken include: HR,
BP, oxygen saturation and ability to perform on a memory test. The individuals in the anaerobic group were asked to squeeze a hand
dynamometer with maximal exertion and sustain at least 50% of their maximum force until fatigued. Individuals in the aerobic
group ran up and down 4 flights of stairs five times. The control group did not complete any exercise; only baseline physiological
measurements were taken.
Results: There was no significant difference in short term and long term memory retention between groups. There were significant
decreases in memory retention within all groups, associated with normal memory loss.
Conclusion: This study can offer no significant evidence that there is a correlation between acute anaerobic or aerobic exercise and
memory retention.
Introduction anaerobic exercise on short and long term
memory retention compared to a non-
In a society that is constantly evolving
exercise control-group.
and increasingly dependent on
technology, people have transitioned to a
more sedentary lifestyle over time. Aware There are many benefits to regular
of this trend, scientists have begun to exercise, and among them many that
question the effects that this sedentary potentially increase memory retention.
lifestyle may have on the human brain Exercise has been shown to have many
and body. Thus, this study specifically beneficial effects in life such as:
targeted college students as well as improving mood, increasing alertness,
individuals with rigorous jobs to explore improving endurance, promoting better
a possible connection between exercising sleep and reducing stress (Mayo
and learning. This target area is an Foundation, 2011). Many times, students
insightful group to study because these skip the gym in order to make time for
individuals are consistently put under studying. Is this really benefiting them?
stressful environments that tend to What extent could aerobic and anaerobic
encourage sedentary lifestyles (e.g. class, exercise have on their memory
tests, homework, jobs). Previous research performance? There are a few widely
has found insignificant results in regards known facts about exercise that lead us to
to the relationship between aerobic believe that short-term and long-term
exercising and learning. Future research effects of healthy exercise can greatly
needs to explore the effects of anaerobic improve memory. By exploring the
exercise as well as to modify the methods relationship of exercise and memory
used to test aerobic exercise. More retention, this study can aid the student
specifically, this study intends to and working populations by helping them
elucidate the effects of aerobic and understand efficient time management
1
for studying, exercising, and work-related exercise and memory performance. Ellis
activities. Ultimately, this can lead to et al. (1987) completed a study where
reductions in stress, improved success, they found no difference in free recall
and a healthier-lifestyle. memory of the control group and test
subjects (Ellis, 1987). On the other hand,
Lambourne et al. (2010) examined
It has been shown that exercise promotes
numerous exercise and memory studies
healthy sleep patterns (Gebhart, 2011).
in their meta-analysis. The authors
Prior research has indicated that healthy
concluded that exercise significantly
sleep is needed to properly store
improved cognitive task performance.
memories (Kuriyama, 2008). During
The authors also concluded that post-
sleep, the human mind resynthesizes and
exercise arousal facilitated speeded
filters memories from the short-term
mental processes; in addition to memory
memory and reformats them for long-
storage and retrieval (Lambourne, 2010).
term memory storage if they are deemed
important for future use (Stickgold,
Within the literature, there are numerous
2008). Regular exercise has also been
methods researchers employed to explore
shown to boost physical endurance and
how aerobic exercises - such as cycling
increase mental alertness throughout the
and running - affect memory recall
day (Mayo Foundation, 2011). The
(Lambourne, 2010). However, there have
activation of the sympathetic nervous
not been many studies specifically looking
system during acute exercise changes
at anaerobic exercise and memory recall.
both hormonal and central processing
Seifert et al. (2011) found the blood
activity that increases alertness.
saturation of oxygen in the brain
Additionally, exercise has been shown to
increased during light anaerobic exercise
be psychologically rewarding and mood
(Seifert, 2011). The ability to store and
boosting (Gebhart, 2011). The physical
maintain memories may be facilitated by
stress during exercise causes release of
an increase in oxygen supply to the brain.
endorphins and dopamine, which act
The conclusions of Seifert et al. (2011)
upon the reward centers of the brain
evidence the importance of both
(Arias-Carrión, 2010). It may be possible
anaerobic and aerobic exercise in this
that memory performance is aided by the
study’s research on memory. Conversely,
healthy sleep, increased alertness, and the
the scientific community does not
reward association caused by exercise.
indicate the best methods to measure
memory recall. Previous research studies
As plausible as this relationship may
have used various methods to measure
seem, there has been much scientific
memory recall. However, the validity of
debate about the correlation between
these studies is up to debate, and only
2
decided upon further research measures indicate the amount of oxygen
(Lambourne, 2010; Tomporowski, 2003). that is reaching the brain.
For this reason, the memory test in this
study was extensively modified during
Our hypothesis is as follows: Will an
pilot studies. The memory test is
aerobic or anaerobic exercise regimen –
described in the “Materials and Methods”
completed immediately before the time of
section.
learning new information – significantly
improve the ability to later recall the
As stated previously, the main focus of
information, compared to control? We
this study was to evaluate the effect
predict that moderate aerobic exercise as
anaerobic and aerobic exercise had on
well as anaerobic exercise will have a
short and long-term memory retention.
positive effect on memory retention. We
Anaerobic exercise was simulated using a
also predict that moderate aerobic
hand dynamometer and normal aerobic
exercise will show a greater positive
exercise was simulated by a stair-running
correlation with memory retention than
exercise. The grid memory test used in
moderate anaerobic exercise or the
this study was developed through pilot
absence of exercise.
testing to calculate memory retention on
Methods
a point-based system. A non-exercising
group was admitted the memory test as a
Five students attending the University of
control group.
Wisconsin Madison conducted research
for this experiment. Subjects who
participated in this experiment were
Blood pressure, heart rate and oxygen randomly selected from the student
saturation were the physiological population of Madison. Each subject filled
out an informed consent form and a
parameters measured to relate the
survey (Figure 1) about aspects of their
physiological effects of the exercise with
lifestyle that were relevant to the study.
the potential effects on memory
retention. The measurement of heart rate
was important for this study because it
Groups
was used to standardize the target heart
rate intensity of exercise for each subject.
Three groups were created in this
Blood pressure and heart rate were also experiment: a control group (Table 1), an
important for charting how the exercise aerobic exercise group (Table 2), and an
regimen affected the sympathetic nervous anaerobic exercise group (Table 3).
Tables 1, 2, and 3 of the “Tables and
system, and thus the central nervous
Figures” section visually detail the
system. Blood pressure and oxygen
methods of each group. All groups
saturation were important because these completed a memory test on the same day
3
of their intervention, as well as-one- Control group subjects did not participate
week-later. in physical exertion. The baseline blood
pressure, heart rate and oxygen
The aerobic exercise group was asked to saturation was recorded for each subject.
run up and down 4 flights of stairs, in five After this, the subject completed the
sets. Resting heart rate, blood pressure, memory test as explained-below.
and oxygen saturation were measured
while subjects were seated before the Subjects were asked to memorize a
exercise. (Tables 1, 2, and 3). Subjects memory grid after completing the
were then encouraged to run up and exercise regimen. The memory grid was a
down the stairs at the intensity that 5x5 grid of different color shapes and
would maintain their heart rate within symbols; drawn in different quadrants of
their optimal aerobic range. This aerobic the grid (Figure 1). Subjects were given
range was defined by the heart rate 45 seconds to look at the grid and try to
reserve determinant of the Karvonian memorize the location, color and
equation, explained in the “Analysis” orientation of all shapes on the grid. After
subsection. Upon reaching the top of the the 45 seconds, the subject was asked to
stairs - each of the five times - blood complete a survey for 5 minutes.
pressure, heart rate and oxygen Following the 5 minute survey, the
saturation were measured and recorded subject was given an empty 5x5 grid with
(Tables 1, 2, and 3). The subject’s heart 8 different colors to choose from. The
rate was compared to their optimal subject was given 1 minute to draw all the
aerobic range, and the intensity of their correct symbols with correct color and
next stair-running set was adjusted location among the grid. One to two
accordingly. These measurements were weeks later, subjects were given another
taken sitting down with the subjects’ arm empty grid. The subject was given 1
resting on a table to ensure an accurate minute to try and replicate the same grid
reading. After this, the subject completed they had seen using-the-same-methods-
the memory test; explained at the end of as-above.
the “Groups” subsection.
Pulse Oximeter
The anaerobic exercise group used the
hand dynamometer for physical exertion. Heart Rate and oxygen saturation
Subjects were asked to squeeze the hand measurements were taken using an
dynamometer from the time of maximum electronic pulse oximeter. These
force exertion until volitional fatigue, measurements were obtained by placing
which was defined as half of the subject’s the device on the subject’s index finger.
maximum force output. Blood pressure, To ensure accurate measurements, the
heart rate and oxygen saturation were subject’s arm was rested on a table to
taken before squeezing, at the halfway prevent movement and other
point of volitional fatigue, and confounding-variables.
immediately following volitional fatigue.
After this, the subject completed the Blood Pressure
memory test; explained at the end of the
“Groups”-subsection. Blood pressure was measured manually.
To ensure accurate measurements, the
4
subject’s arm was rested on a table to points, where each of the 5 figures was
prevent movement and other worth 3 points. Each figure was scored 1
confounding variables. point for accuracy of shape, 1 point for
use of the right color, and 1 point for
Survey correct positioning of the figure within
the 25 (5x5) box grid. Figure replications
The 5-minute survey (Figure 1) was were either correct or incorrect in terms
administered following the 45 second of those 3 categories. For each figure,
exposure to the memory grid. The survey points in the range of an integer from 0 to
asked the subject their average: amount 3 were assigned. Based on memory test
of sleep, physical activity, food and liquid results, this study sought a relationship in
intake, stress level, and caffeine intake. memory retention between the aerobic
These aspects are potentially confounding exercise group, the anaerobic exercise
variables that may have influenced the group, and the control group.
results of this study. Also, the survey
provided information for future research T-Test and ANOVA analyses were
in the exercise and memory retention employed for each of the three groups. T-
field. Tests were used to compare short and
long term memory retention within
groups and between groups. ANOVA
Analysis analyses were used to compare the short
term and long term memory tests
During the intervention, both heart rate between all groups.
and oxygen saturation were monitored
with the pulse oximeter. More specifically, Results
the heart rate for the aerobic exercise
group was maintained within the aerobic The physiological measurements
range of the Karvonian heart rate reserve recorded during testing for the Control,
equation. The maximum any subject’s Aerobic, and Anaerobic groups are
heart rate was allowed to rise was presented in Tables 1, 2, and 3,
defined as 200 - the subject’s age (200 - respectively. The final survey information
age = maximum heart rate). The aerobic is presented in Table 4. Individual
range of a subject was defined as the 70- Memory Test scores for the Aerobic,
80% of the difference between the Anaerobic, and Control groups are
maximum heart rate and resting heart presented in Figures 5, 6, and 7,
rate This is mathematically written as: respectively.
[.7(maximum heart rate - resting heart
rate), .8(Maximum heart rate - resting Significant decreases in memory tests
heart-rate)] in this study. --------------------- scores from short to long term were seen
- - across all three groups (control,
anaerobic and aerobic). Figure 2 depicts a
Statistical analyses were completed for visual representation of the average
the data comparing all three groups. To decline in memory retention of the
analyze subject memory retention, a Memory Grid (Figure 1) over 1-2 weeks.
memory test scoring system was T-Test Analyses (Table 5) revealed the
developed that consisted of a total of 15 memory retention declined through the
5
period of 1-2 weeks from the original (control, anaerobic, aerobic) in the long
learning period of the memory grid until term (Figure 4). This analysis showed no
the short term memory test was significance with a p-value of 0.9305.
completed.
After comparing the short term and long
T-Test analyses were employed to relate term separately we did an ANOVA test
data within groups. In the control group, comparing the absolute differences
we see a p-value of 0.00507, which is less between the short term and long term in
than the alpha significance value of 0.05, the control, anaerobic and aerobic groups.
and thus evidently (Table 5). More This represents the decline in memory
specifically, this evidences a significant retention for each subject. This ANOVA
decrease in memory test scores from the analysis again demonstrated no
short term to the long-term tests. In the significant difference with a p-value of
anaerobic group, we see a significant p- 0.3587 (Figure 8).
value of 0.0119 (Table 5). This
demonstrates a significant decrease in ANOVA analysis was done comparing the
memory test scores from short term to absolute differences between the genders
long term memory tests. Finally, the in this study. This ANOVA analysis
aerobic group provides a p-value of demonstrated no significant difference
0.04242 (Table 5). This p-value indicates with a p-value of 0.1019 (Figure 9). This
a significant decrease from the short-term illustrates there is no differences between
memory test to the long-term memory males and females in short and long term
test. memory retention.
T-Test analyses were employed to relate Discussion
data between groups (Table 5). In these
analyses we compared short term Some research has shown that intense
anaerobic to short term aerobic anaerobic exercise leads to increased
(p=0.3697), long term anaerobic to long memory retention, specifically the
term aerobic (0.9036), short term learning of new vocabulary, when
anaerobic to short term control (0.6584), compared to an aerobic exercise group
long term anaerobic to long term control and a control sedentary group (Winter,
(p=0.7820), short term aerobic to short 2007). This differed from our results
term control (p=0.1833), and long term because we didn’t offer evidence of a
aerobic to long term control (p=0.6620). statistical difference in memory retention
Within theses six group pairings we found between our control and anaerobic
no significant difference (Table 5). groups. Winter’s aerobic exercise group
experienced a decrease in memory
ANOVA analyses were completed to retention, while our results had a
compare data between groups. An ANOVA statistically insignificant decrease in
test was completed between the three memory retention compared to our
groups (control, anaerobic, aerobic) in the control. Although Winter et. al (2007)
short term (Figure 3). This analysis showed a decrease in memory retention
showed no significance with a p-value of with aerobic exercise, a majority of the
0.6574. Another ANOVA test was studies referenced in this study
completed between the three groups supported that there was a positive
6
correlation between an acute session of
aerobic exercise and memory retention Our results may be skewed because our
(Brisswalter, 2002; Pontifex, 2011; long term variable for all groups has an
Martins, 2013; Coles, 2008). One study unequal amount of one-week and two-
showed evidence that aerobic activity has week post memory tests caused by
beneficial effects on memory by missed time due to the fire in our lab
increasing the size of the hippocampus building, and our spring break. Thus,
and thus increasing serum levels of BDNF these differences in testing conditions
(brain derived neurotrophic factors). confound our results, limiting our ability
BDNF is a protein vitally linked to to correlate the low scores with the
learning and memory (Erickson 2010). amount of exercise in the group.
However, our own research study did not
show similar results. Another confounding variable was the
differing amounts of sleep subjects had, as
referenced by our survey. Compared to
Our results demonstrate that our control our control group that slept an average of
group performed with the highest eight hours, both exercise groups slept an
memory test scores, both in the short and average of seven hours. This variable
long term, as compared to the two could have been vital, as studies have
exercise groups. Upon analyzing these shown a positive correlation between
results, there are some issues to address sleep and improved memory performance
regarding the accuracy of our findings. (Kuriyama).
Our small sample size of ten people per
group is not large enough to yield Additionally our surveys demonstrated
significant results. With more people to an imbalance in gender distribution of
test, we would be able to obtain a normal our groups. Even though our sample was
bell curve, which would increase the randomized, each of the two exercise
significance of our test. We were groups had one female participant. This is
incapable of testing more subjects due to due to the fact that we only had ten
the limitations of equipment, limited time subjects per group. The control group
in the lab, and a missed lab day due to a was the only one with a relatively
fire in the Medical Sciences Center balanced distribution of six females and
building. four males. Despite the differences in
gender we see no significant differences
Our aerobic exercise group required a in results between males and females in
relatively time-consuming test, further memory retention both short and long
limiting the number of subjects we could term (Figure 9). In the future, a larger
experiment. Among these subjects, two of sample size can correct for the gender
the aerobic stair-running participants did disparity.
not meet the heart rate reserve
requirements as set by our initial Although we did have a five minute
definitions. Resultantly, any data related survey between the exercise and memory
to memory performance for these test, the subjects of the exercise groups
individuals cannot truly and accurately be may have been distracted by the exercise
linked to aerobic exercise, as it falls short or out of breath. This may have affected
of our definition. their focus for the immediate task of
7
committing the shapes, colors and References
positions of the figures to memory, and
thus affecting results. 1. Arias-Carrion O. et al (2010). Dopaminergic reward
system: a short integrative review. International
Archives of Medicine. 3:24.
The addition of a BDNF serum level
measurement would allow for greater 2. Blumenthal, James A. “Long-term Effects of Exercise on
Psychological Functioning in Older Men and Women”.
insight on how memory was affected by a Journal of Gerontology. Oxford Journals, October 16, 1990.
short period of exercise. Due to safety http://geronj.oxfordjournals.org/content/46/6/P352.short#
cited-by. April 9, 2013.
restrictions, our lab was unable to take
such measurements. Other labs outside 3. Brisswalter, J. “Effects of Acute Physical Exercise
of Physiology 435 could replicate our Characteristics on Cognitive Performance”. Journal of
Sports Medicine 2002;32(9):555-66. Pubmed.
methods with the addition of this
http://www.ncbi.nlm.nih.gov/pubmed/12096929. April 9,
physiological measurement to gain a 2013
better understanding and more
4. Coles K & Tomporowski P (2008). Effects of acute
comprehensive results. exercise on executive processing, short-term and long-
term memory, Journal of Sports Sciences, Volume 26,
Issue 3, Pages 333-344, DOI:
Our results are inconclusive with regards 10.1080/02640410701591417
to the effect of exercise on memory
5. Erickson K et. al (2010). Exercise training increase size
retention. Future research must include
of hippocampus and improves memory, Proceedings of
as many subjects as possible to obtain the National Academy of Sciences of the United States of
America, Volume 108, Issue 7, Pages 3017-3022.
normality and significance. Also,
DOI:10.1073/pnas.1015950108
variables must be controlled so that any
results found could be linked to exercise 6. Fritz K. et al (2012). The Effect of Moderate Aerobic
Exercise on Memory Retention and Recall. Journal of
instead of the natural process of Advanced Student Science.
forgetting information.
7. Gebhart C, Erlacher D, Schredl M (2011). Moderate
Exercise Plus Sleep Eudcation Improves Self-Reported
Conclusion Sleep Quality, Daytime Mood, and Vitality in Adults with
Chronic Sleep Complaints: A Waiting List-Controlled
Trial. Hindawi.2011.
We found no significant differences in
memory retention between the exercise 8. Kuriyama K et. al (2008). Sleep accelerates the
improvement in working memory performance, The
groups compared to the control group. Journal of Neuroscience, Volume 28, Issue 40, Pages
There was a statistically significant 10146-1015, DOI: 10.1523/JNEUROSCI.2039-08.2008
decrease within all groups between the
9. Lambourne K & Tomporowski P (2010). The effect of
short term and long term memory
exercise-induced arousal on cognitive task performance:
retention test scores. This shows that a meta-regression analysis, Brain Research, Volume
1341, Pages 12-24, DOI: 10.1016/j.brainres.2010.03.091
there was a decrease in memory retention
over time, but the decrease in retention
did not differ significantly between all 10. Martins A et. al (2013). Moderate intensity exercise
facilitates working memory, Psychology of Sport and
groups. Based on our study, we cannot Exercise, Volume 14, Issue 3, Pages 323-328, ISSN 1469-
conclude that there is a correlation 0292, 10.1016/j.psychsport.2012.11.010.
between acute anaerobic or aerobic
11. Mayo Foundation for Medical Education and Research.
exercise and memory retention. “Exercise: 7 benefits of regular physical activity.”
MayoClinic.com. Accessed 3 February 2013.
www.mayoclinic.com/health/exercise. Updated 23 July
2011.
12. Pontifex MB et. al (2009). The effect of acute aerobic and
resistance exercise on working memory, Medicine &
8
Science in Sports & Exercise, Volume 41, issue 4, Pages
927-934; DOI: 10.1249/MSS.0b013e3181907d69.
13. Seifert, Thomas, et al (2011). "Sympathetic Influence on
Cerebral Blood Flow and Metabolism during Exercise in
Humans." Progress in neurobiology 95.3 : 406-26.
14. Stickgold R, Ellenbogen JM(2008). Sleep On It: How
Snoozing Makes You Smarter. Scientific American Mind.
15. Tomporowski, P (2003). Effects of acute bouts of
exercise on cognition. Acta Psychologica112:3. 297-324.
16. Winter B et. al (2007). High impact running improves
learning, Neurobiology of Learning and Memory, Volume
87, Issue 4, Pages 597-609, ISSN 1074-7427,
10.1016/j.nlm.2006.11.003.
Tables and Figures:
Tables Subsection
Table 1: Data collected on subjects in control group.
Subject physiological measures at baseline.
Sub =Subject
BP = blood pressure (mmHg);
O2 SAT = oxygen saturation percent;
HR = heart rate (beats/min);
ST = short term memory test score;
LT = long term memory test score
AVG = average value
9
10
Description:group ran up and down 4 flights of stairs five times. The control exercise was simulated by a stair-running 5x5 grid of different color shapes and.
