© 2011 Baylor College of Medicine Children’s Museum of Houston – PowerPlay Classroom Activities: Activity 3

Students will measure their heart rates after a variety of physical activities, and then compare their post-exercise heart rates to their resting rates. They also will compare their heart rates to those of the other students in their groups.

Two class periods of 45 – 60 minutes: one to collect data and a second to process, present and interpret measurements

TIME

1

MATERIALS PER CLASS OR GROUP OF STUDENTS • Stopwatchwithsecondhand,watcheswithsecondhand,orclassroomclock

• CDplayerorothermusicplayer• Onemusicselectionwithoutwordsthathasastrong,up-tempobeat

• Onemusicselectionwithoutwordsthatisslowandrelaxing

PER STUDENT • Accesstoaclockorwatchwithasecondhand(orone

stopwatchperteam)• Copiesof“YourPulseRate”and“HeartRateObserva-tions”studentsheets

• Optional:Labnotebook

Everyday,itseemswehearorreadabouttheimportanceofexerciseforhearthealth.Why?Whatistherelationshipamongtheheart,circulation,andexercise?TheChildren’sMuseumofHouston’sPowerPlayexhibitisdesignedtoteachyoungpeopleabouthearthealthandreinforcehealthybehaviors,asstudentsdiscovernewwaystobephysicallyactive.Whiletheyprogressthroughtheexhibit,studentswillbeabletotrackheartrate,measurestrength,andexamineperformancelevels.Thisactivitywillenablestudentstolearnhowtheirheartsrespondtophysicalactivity.ItshouldbecompletedbeforetheyvisittheMuseum. Evenwhenyouaresleeping,reading,orwatchingTV,yourbodyusesoxygenandnutrients,andproducescarbondioxideandotherwastes.Whenyougetupandstartmov-ingaround,yourbodydemandsmoreoxygenandproducesmorecarbondioxideaswaste.Thesedemandsincreaseevenfurtherifyoustartrunningordoinganotherstrenuousactivity.Thecirculatorysystemrespondsbyraisingtheheartrate(howoftenthepumpcontracts)andstrokevolume(theamountofbloodpumpedwitheachcontraction)toincrease

thecardiacoutput(thevolumeofbloodpumpedfromtheleftventricleperminute).Duringexercise,heartratecanrisedramatically,fromarestingrateof60–80beatsperminutetoamaximumrateofabout200forayoungadult. Apumpingheartmakesthesoundwecallthe“heart-beat.”The“lub-dub”ofaheartbeatisactuallythesoundofbloodbeingpushedagainsttheclosed,one-wayvalvesoftheheart.Onesetofvalves(tricuspidandbicuspid)closesastheventriclescon-tract.Thisgeneratesthe“lub”ofourheartbeat.Asecondsetofvalves(pulmonaryandaortic)closeswhenpressureintheventriclesislowerthanthepressureintheaortaandpulmonaryartery.Thisproducesthe“dub”ofourheartbeat. Astheheartbeats,itforcesbloodfromtheventriclesintothemus-cular,elasticwallsofthearteries,causingthemtoexpand.Eacharterywallthencontractsto“push”thebloodonward,furtherthroughthebody.Youcanfeelthose“pulses”ofblood,movingthroughthearteriesinrhythmwithyourheartbeat.Thenumberofpulsesperminute,usuallyreferredtoaspulserate,is

TEXAS ESSENTIAL KNOWLEDGE AND SKILLS (TEKS) OBJECTIVES

SCIENCE 3.2.A-F; 4.2.A-F; 5.2.A-F Studentusesscientificinquirymeth-odsduringlaboratoryandoutdoorinvestigations.

3.4.A-B; 4.4.A-B; 5.4.A-B Studentsknowhowtouseavarietyoftools,materials,equipment,andmodelstoconductscienceinquiry.

3.2.E; 4.2.E; 5.2.E Studentsdemonstratethatrepeatedinvestigationsmayincreasethereli-abilityofresults.

HEALTH 3.1.A; 4.1.F; 5.1.E Studentswillrecognizeandexplainwaystoenhanceandmaintainhealth.

4.2.B; 5.2.A Thestudentrecognizesthebasicstructuresandfunctionsofthehumanbodyandhowtheyrelatetopersonalhealththroughouttheirlifespanbydescribingthebasicfunctionsofthemajorbodysystemssuchasthecirculatorysystem.

measuredinbeatsperminute(BPM).Theaveragepulserateforachildrangesfrom60to120BPM.

ENGAGE 1. Askstudentsiftheyknow

howtomeasuretheirheartrate.Distributecopiesof“YourPulseRate”studentsheets.

2. Showstudentshowtomeasureheartrate(beatsperminute)byfeelingforthesurgeofbloodsurgethroughanartery.Haveeachstudentfindhisorherpulsebyplacingslightpressureonthewristwiththemiddleandringfin-gers.Tellstudentsnottousethethumb,becauseithasapulseofitsown(seeillustration,right).

3. Allowstudentstopracticetakingtheirpulseratesseveraltimeswhileyoucountoff15-secondintervals.Instructstudentstomultiplythe15-secondpulsecountbyfourtodeterminehowmanytimestheirheartsbeatinoneminute.

EXPLORE 1. Askstudentsiftheythinkheartratecanvary,orifit

alwaysisthesame.Ask,What kinds of situations might cause heart rate to change? [exercise,rest,standing,walkingupstairs,nervousness,excitement,etc.]

2. Distributethe“HeartRateObservations”sheets.3. Reviewtheactivitysheetwithstudents,stoppingperiodi-

callytoaskquestionsandmakesuretheyunderstandthecontent.

4. Askstudentstocompletethepredictionsectionforthefirstactivitylisted(i.e.,studentsshouldcheckwhethertheyexpecttheirheartratestoincrease,decreaseorstaythesamewhenthey“Listentosoft,slowmusic”).Explainthatpredictionsshouldbemadeinorder,andfor

onlyoneactivityatatime.(Theoutcomeofeachactivitymayinfluencestudents’predictionsforthenext.)

5. Havestudentssitquietlyforoneminute.Then,instructthemtocounttheirpulseswhileyoutimethemfor15seconds.Toestablishtheirresting,orbeginning,pulserates,studentsshouldmultiplybyfourthenumberofpulsestheycountedin15seconds.Havethemrecordtheirbeginningpulseratenumbersontheappropriatelinesoftheir“HeartRateObservations”sheets.

6. Havetheclasssitquietlyandlistentosoftmusicforoneminute.Then,haveallstudentsmeasureandrecordtheirpulseratesonceagain.Continuetoleadstudents,asaclass,throughthefirstthreeactivitiesonthesheet.Duringthedeepbreathingexercise,makeapointoftell-ingstudentswhentoinhaleandexhale,toensurethattheymaintainaveryslowpulserate.Instructstudentstocontinuethispatternofslowbreathingastheytaketheirpulses.

7. Havestudentscompletetheremainingactivitieslistedonthesheet,inorder.Eachstudentmayworkwithapartner,ifdesired.Remindstudentstorecordtheirpulseratepredictionsbeforeeachstep.Studentsshouldapplyanythingtheylearnedfrompreviousexperienceswhenmakingeachnewprediction.

8. Besurestudentshavesufficienttimetoregaintheirrest-ingpulseratesbeforebeginningeachnewactivity.Youmaywishtohavethemrecordhowlongittakestoreturntotheirrestingheartrates.(Pulserateswillrecovermorequicklyifstudentsareseated.)Somestudents’heartratesmayfallbelowtheirrestingratesbeforereturningtonormal.Thisiscommon.

9. Besensitivetostudentswhomayfeeluncomfortabledoingjumpingjacksorsit-upsinfrontoftheclass.

10.Instructstudentstocompletethewrittenquestionsbelowthetableontheactivitysheet.

EXPLAIN 1. Havestudentsformgroupsoffour.Eachgroupshould

combineitsdata,createapresentationofitscollectiveresults(graph,table,pictures,etc.),andpresentitsfind-ingstotheclass.

2. Ask,What have you learned about heart rate? Studentsshouldhaveobservedthatheartrateincreasesduringmorestrenuousphysicalactivities.

3. Ask,What happened to your breathing during activities that increased your heart rate? Studentsshouldhavenoticed

© 2011 Baylor College of Medicine Children’s Museum of Houston – PowerPlay Classroom Activities: Activity 3 2

Radial PulsePoint

1PulsesiterecommendedforthegeneralpublicbytheNationalHeart,Lung,andBloodInstitute,NationalInstitutesofHealth.

Illustration©Williams&Wilkins.Allrightsreserved.

The safest and most common site to check pulse is on the thumb-side of the wrist (radial pulse).1 Use the middle finger and ring finger together to apply slight pressure at the location

shown above.

thatbreathingrateandvolumeofairtakeninincreasedwhenthephysicalactivitybecamemoredemanding.

4. Helpstudentstounderstandtherelationshipbetweenthebody’sneedformoreoxygenduringexerciseandtheheart’sefforttodeliverthatoxygen(bypumpingbloodmorequickly).

ELABORATE 1. Askstudents,Why would an athlete have a slower rest-

ing heart rate than a non-athlete? Discussthenormalrestingheartrateforanaverageadult(72BPM),com-paredtothefollowingaveragerestingheartratesinbeatsperminute.

a. Weightlifter 65BPM b. FootballPlayer 55BPM c. Swimmer 40BPM d. MarathonRunner 40BPM

2. Ask,Why would a slower heartbeat during rest indicate a healthier heart? Explainthatregularexercisestrengthenstheheart,andthatawell-conditionedheartcanpumpthesameamountofbloodwithfewerbeats.Cardiovascularexercise(suchasswimmingandrunning)alsoincreasesthesizeofcardiacmusclecellsandtheheartchambers,whichactuallycausesthehearttogrowlarger.Therefore,evenwithalowernumberofbeatsperminute,ahealthy,

fitheartpumpsmorebloodthanaheartthatisnotac-customedtoexercise.

3. Toachievethebesthealth,wemustmakeexercisealife-style,notatemporaryfitness“kick.”Studieshavefoundthatnon-activityforaslittleasthreeweekscanreduceheartmusclesizeandstrokevolume(amountofbloodpumpedfromtheleftventricleineachcontraction).

EVALUATE Toconcludetheactivity,havestudentswriteajournalentrydescribingwhattheylearnedabouttheconnectionsbetweenactivityintensityandheartrate.Studentsshouldcompletethefollowingstatements,andmaywanttodrawpicturestoaccompanytheirwords.

Idiscovered...Ilearned...Ineverknew...Iwassurprised...Ienjoyed…

FundedbyaScienceEducationPartnershipAward(SEPA)R25RR022697,fromtheNationalCenterforResearchResources,acomponentoftheNationalInstitutesofHealth.

Theactivitiesdescribedhereinareintendedforschool-agechildrenunderdirectsupervisionofadults.Theauthors,BaylorCollegeofMedicine,theChildren’sMuseumofHoustonandfunderscannotberesponsibleforanyaccidentsorinjuriesthatmayresultfromconductoftheactivities,fromnotspecificallyfollowingdirections,orfromignoringcautionscontainedinthetext.

© 2011 Baylor College of Medicine Children’s Museum of Houston – PowerPlay Classroom Activities: Activity 3 3

FormoreinformationaboutPowerPlayandadditionalclassroomactivitiesonothertopics,pleasevisitwww.bioedonline.org.

http://www.bcm.edu http://www.cmhouston.org http://www.ncrrsepa.org

© 2011 Baylor College of Medicine Children’s Museum of Houston – PowerPlay Classroom Activities: Activity 3 4

Radial Pulse Point

Youcanmeasureyourheartratebytakingyourpulse.Eachpulseyoufeelinyourwristrepresentsoneheartbeat.

Tofeelyourpulse,lightlypressyourringandmiddlefingersagainsttheinsideofyourwrist(seeillustration,right).Donotuseyourthumb,becauseithasapulseofitsown.Whatdoyouthinkhappenstoyourheartrateafterdifferentkindsofphysicalactivity?You’reabouttofindout,asyouobservetheresponseofyourpulseratetoavarietyofactivities.

1. Sitquietlyforoneminute.Then,measureyourrestingheartratebycountingyourpulsefor15seconds.

2. Multiplythenumberofpulsebeatsbyfourtocalculatethenumberofbeatsperminute.

beats in 15 seconds x 4 = (Beats Per Minute)

© 2011 Baylor College of Medicine Children’s Museum of Houston – PowerPlay Classroom Activities: Activity 3 5

Before starting each activity listedinthetablebelow,predicthowthatactivitywillaffectyourpulseratebycheckingtheappropriatebox.Then,carryouteachactivityforoneminute.Stopandimmediatelytakeyourpulsefor15seconds(multiplybyfourtoobtainthenumberofbeatsperminute).Besuretodotheactivitiesinorder,andtomakeonlyonepredictionatatime.

Before starting each new activity, sitquietlyuntilyourheartrateisclosetoyourrestingrate.Calculatethedifferencebetweenyourrestingpulserateandyourheartrateaftereachactivity.Recordthedifferenceintheappropriatecolumn.

1. Howdothedifferentactivitiesaffectyourheartrate?

2. Howdoyourpredictionscomparetoyouractualdata?

3. Whatdidyoudiscover?Werethereanysurprises?Howwillyoupresentyourfindingstotheclass?

PULSE RATE IMMEDIATELY AFTER

ACTIVITY

DIFFERENCE BETWEEN RESTING PULSE RATE AND RATE AFTER ACTIVITY

(BEATS PER MINUTE)

PREDICTED EFFECT OF ACTIVITY ON PULSE RATE

(CHECK ONE BOX)

SameDecreaseIncrease

1. Listen to soft, slow music

2. Listen to fast music

3. Breath deeply

4. Walk briskly around the room

5. Do jumping jacks

6. Do sit-ups

7.*

SameDecreaseIncrease (Beats Per Minute)(Conducted for 1 Minute)

TYPE OF ACTIVITY

*Record activity of your choice.