1. Measurement of Sedentary vs. Active College Students’ Exam Stress Levels
By Bailey Archer, mentored and funded by Dr. Stephen Luckey
Abstract:
A numberof investigationshave demonstratedthatphysical activity(suchasexercise) positively
impactsa person’s mental andphysical well-being.Moreover,studieshave suggestedthatphysical
activityreducesanindividual’sstressresponse.Investigatorshypothesizethatexercise itself isaphysical
stressorand,therefore,the bodyadaptstoexperiencingstressresultinginareducedresponse toother
stressors.Cortisol isthe primaryhormone releasedbythe bodyinresponse tostress.Althoughcortisol
may have short-termbenefits,chronicelevationof cortisol levelshasbeenlinkedtoanxiety,depression,
emotionchallenge,fear,andhelplessness.Cortisolcaneasilybe measuredinsalivawhichcanprovide
an indicationof the physiologicalstressanindividual isexperiencingduringthe time the sample istaken.
In thisstudy, salivarycortisol levelsinstudentswhoare eitherphysicallyactive (getatleast150 minutes
of moderate torigorousphysical exerciseperweek)orsedentary(little tonoexercise) were takenat
differenttime points.The time pointsincludedabaseline non-stresstime,immediatelypriortoa final
exam,andimmediatelyfollowingafinal exam. Itwashypothesizedthatphysical activity wouldloweran
individual’sresponsetostressand wouldtherefore decrease salivacortisol levelsduringstressful
situations. The dataobtainedprovedthe hypothesistobe correctbecause itdemonstratedthatthe
sedentarystudentshadasignificantlylargerpercentincrease incortisol levelsfromtheirbaseline levels
to justprior tothe examthanthe exercise studentsdemonstrated. Thisfindingbenefitstudentswho
wishto lowertheirstresslevelsaroundexams whichcouldleadtoimprovedacademicperformances.
Introduction:
A numberof investigationshave shownthatphysical exercisehasapositive impacton a
person’s mental andphysical well-being.Moreover,studieshave suggestedthatphysical activity
reducesanindividual’sstressresponse.Investigatorshypothesize thatexercise itself isaphysical
stressorand,therefore,the bodyadaptstoexperiencingstressresultinginareducedresponse toother
stressors2
.
Cortisol isa glucocorticoidreceptormade bythe adrenal cortex and isthe primaryhormone
releasedbythe bodyinresponse tostress. The effectsithasonthe body include,butare notlimitedto,
elevatedbloodpressure,elevatedbloodsugarlevels,andreductionof the body’simmune response.
Althoughcortisol mayhave short-termbenefits,chronicelevation of cortisol levelshasbeenlinkedto
anxiety,depression,emotionchallenge,fear,andhelplessness3
.Chronicincreasedcortisol levelshave
alsobeen showntodecrease memoryrecall4
.Cortisol caneasilybe measuredinsalivawhichcan
provide anindicationof the physiological stressanindividual isexperiencingduringthe time the sample
istaken,howeveritshouldbe notedthatbodilycortisol levelsfluctuate basedontime of day.Cortisol
levelsare generallyhighestbetween2-3hoursthat an individual normallywakesupandgradually
decrease throughoutthe restof the day.Peaksincortisol levelscanoccurdue to stressful situations,
eating,drinking,aswell asduringstrenuousphysical exercise1
.
Methods:

2. Due to the fact thatthe studycontainedhumansubjects,anIRBprotocol wasfirstwrittenand
approvedbefore anytestingwasperformed.Subjectswere thenrecruitedforeachgroup(sedentary
and exercise).Inordertobe consideredasedentaryindividual,participantsmustcomplete lessthan 150
minutesof exerciseperweek. The exerciseindividuals,onthe otherhand,mustcomplete more than
150 minutesof moderate torigorousexercise eachweekwhichisthe WorldHealthOrganization’s
minimumrecommendedamountof weeklyexerciseahealthy individual shouldperformeachweek.
Once the subjectswere recruited,theywererequiredtomaintaintheirstatusof beingsedentaryor
active and logthe exercise performedeachweek.Salivarycortisol levelswereobtainedusingsalivettes
at three differenttime periodsthroughoutthe course of the study.The initial cortisol samplewastaken
duringa non-stressfuldayatthe same time of dayas the individual wouldbe takingtheirfinal examin
the future because cortisol levelsre influencedbytime of day.The secondsample wastakenjustprior
to the individualtakingafinal exam,andthe thirdsample wastakenjustafterthe individual’sfinal exam
was completed.
The salivetteswere thenspundownandthe salivafromeachindividualwasrunintriplicate
usingan LDN Cortisol SalivaELISA. A standardcurve was thengeneratedfromthisELISand the cortisol
levelswere obtainedbycomparingthe wavelengthsobtained fromthe ELISA foreach sample tothis
standardcurve.The cortisol concentrationswerethenaveragedandthe percentincreasesand
decreasedwere calculatedforeachindividual ateachtime pointandcompared.
Data and Results:
Overall,21 studentswere includedinthe studywith5beingstudentathletes,10beingnon-
studentathlete exercisers,and6sedentaryindividuals.Several individualswere thrownoutdue to
beingonbirthcontrol or anxietymedication.Also,one individual wasincludedinthe exercisegroup
whois a studentathlete butwasinjuredatthe beginningof the studyandwas unable todo much
exercise throughoutthe course of the study. The individualwasincludedinthe exercise groupbecause
of the amountof rigorousexercise theirbodywasusedtogoingin to the study,eventhoughthatlevel
of exercise wasn’tcontinuedthroughoutthe time periodinwhichthe cortisol sampleswere taken.
The studentathlete groupdefinitelyhadthe highestaverage numberof minutesof exercise per
week(figure 1),howeverthe percentchangesincortisol levelswereextremelysimilartothose of the
non-studentathlete exercise groupmemberswhoexercisedasmalleramountof time perweek.The
sedentaryindividualshadsome exerciseperweek,butthe exerciseamountdidnotexceedthe amount
necessaryforthemto be consideredinthe exercise group.
The percentdifferences(figure 2) of cortisol levelsforeachgroupof individualsare shownin
figure 2. The crucial sectionof the graphto note are the firstsetof bars showingthe percentincreases
incortisol levelsfromthe baselinetojustpriorto the exam.The difference betweenthe twoaverage
percentincreaseswassignificant,withap-valueof .013. The other twosetsof comparisonsdonotshow
significantdata.
Table 1. Numberof subjectsineachgroup and the
rationof malestofemalesinthe individualgroups.

3. Group # of participants Male to Female Ratio
Athletes 5 2:3
Exercise 10 3:7
Sedentary 6 6 female
Figure 1. demonstratesthe average numberof exerciseinminutesperformedeachweekbyeachgroup
of participants.Standarderrorbarsincluded.
0
100
200
300
400
500
600
700
800
900
1000
Student Athletes Non-Student
Athelete
Exercise
Sedentary
AverageExercise(Minutes)
Average Exercise (minutes) For Each Group

4. Figure 2. The graph showsaverage cortisol concentrationsof all participantsineachgroupwith
standarderror bars. Pvalues:A to B: P=.013, A to C: P>.05, B to C: P>.05.
Discussion:
The data obtainedinthisstudyprovedthe hypothesisthatstudentswhodonotexercise will
have higherpercentincreasesincortisol levelsthanthose studentswhodoexercisetobe correct. The
resultsshowedasignificantdifference inpercentcortisolincreasesfrombaselinetopre-examtime
betweenthe twotestgroupsindicatingthatexercise doesimpactthe body’sstresscortisol responsesin
a positive manner.Thismeansthatstudentswhoexerciseregularlywill have smallerpercentincreases
intheirbodilycortisol levelsgoingintoexamswhichispotentiallyveryimportantbecauseif increased
cortisol levelsaroundexamtime decreasememoryrecall,highercortisol levelswill likelyinhibitthe
student’sabilitytorecall informationneededforthe examandthustheywill notdoas well onthe
exam.
Althoughthe studyyieldedsignificantresultsprovingthe hypothesistobe correct,the data
wasn’texactlyasextreme aswas hoped,meaningthatthe difference betweenexercisersandsedentary
studentswasn’taslarge as it wasinitiallypredictedtobe.There were several crucial limitationstothis
study.Firstof all, the sample size obtainedwasrathersmall,especiallythe numberof sedentary
individualsobtained. Also,ahuge issue wasnot findingenoughindividualsfromthe same class which
meantthat not everyone tookthe same final examandthereforenoteveryonewasintroducedtothe
same amountof stressinthat the OCHEM final examwasprobablyalittle more stressinducingthanthe
philosophyUCORfinal exam. Finally,amajorconcernwiththisstudy wasthat the exercise grouptended
to have lowerstressresponsesoverall,howeveracouple of individuals still hadfairlylarge increasesin
cortisol levels(largerthansome of the sedentarystudents’response increases). A possibleexplanation
0%
100%
200%
300%
400%
500%
600%
Non-Stress to Pre-
Exam
Non-Stress to Post-
Exam
Pre-Exam to Post-
Exam
PercentDifferenceinCortsol
Level
Percent Differences of Cortisol Concentration
Exercise vs. Sedentary
Exercise

5. for thiscouldbe that thiscortisol increase seemslike alot,butmaybe it‘sinfact small comparedto
whatthe increase wouldbe if theyweren’texercisingregularly.
Since there were some clearlimitationstothe study, itwouldbe greatto continue the study
witha much largersample size,all of whom are sedentarytobeginwith.Initial baseline non-stress
samplescouldbe takenandthen the subjectscouldall be introduced tothe same stressorandpre and
poststressorsamples couldbe obtainedlikebefore.Then,these same individualscouldbe put ona
regularworkoutroutine for6 monthsand thenintroducedto a slightly differentstressorinducinga
similarstresslevel andcortisol samplescouldbe takenduringthisstressoraswell.The percent
increasesforeachindividualcouldthenbe analyzed tosee if there were decreasesinthe amount of
stressresponse theyshowedfromwhentheywere sedentarytowhentheywere exercising.
References:
1. Cortisol SalivaELISA." Immunoassaysandservices.LDN.
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ISSN:14034948.
3. Rimmele,Ulrike,et.Al (2007). TrainedMen Show LowerCortisol,HeartRate,and Psychological
ResponsestoPsychosocial StressComparedwithUntrainedMen. Psychoneuralendocrinology,
32, 628-635.
4. Wolf,O.T.; Convit,Antonio;McHugh,P.F.; Kandil,E.;Thorn,E. L.; De Santi,S.; McEwen,B. S.; de
Leon, M. J. Cortisol differentiallyaffectsmemoryinyoungandelderlymen.Behavioral
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7044.115.5.1002Wolf, O. T.; Convit,Antonio;McHugh,P.F.;Kandil,E.;Thorn, E. L.; De Santi,S.;
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