how is my breathing rate related to my...

How Is My Breathing Rate Relatedto My Pulse?

Have you ever raced after someone, trying to catch up? Whenyou finally caught up, you may have felt your heart pounding,and you were probably out of breath. In this investigation, youwill use what you’ve learned about the circulatory andrespiratory systems and the purpose of blood to understand theconnection between your breathing rate and how fast yourheart may be pounding.

Your group will be assigned to a physical activity and worktogether to collect data on your heart and breathing rates. Thetask will have these roles: the “timer,” the “runner/jumper” andthe “pulse keeper.” The “pulse keeper” should be the one whocan find the pulse the easiest on the other person’s wrist. Youshould practice taking these rates a few times before you begininvestigating.

Record your data at rest and after 1 minute of the activity. Thenmake a table to show your findings. Be sure to include titles forthe columns and rows. Next, use your data table to create adouble-line graph that shows both rates and what youdiscovered about the relationship between breathing rate andpulse. Your conclusions should tell whether your prediction wassupported by the data.

1 of 24How Is My Breathing Rate Related to My Pulse?

Copyright 2007, Exemplars, Inc. All rights reserved.

How Is My Breathing Rate Related to My Pulse?

Suggested Grade Span

6–8

Task

Have you ever raced after someone, trying to catch up? When you finally caught up, you mayhave felt your heart pounding, and you were probably out of breath. In this investigation, youwill use what you’ve learned about the circulatory and respiratory systems and the purpose ofblood to understand the connection between your breathing rate and how fast your heart maybe pounding.

Your group will be assigned to a physical activity and work together to collect data on your heartand breathing rates. The task will have these roles: the “timer,” the “runner/jumper” and the“pulse keeper.” The “pulse keeper” should be the one who can find the pulse the easiest on theother person’s wrist. You should practice taking these rates a few times before you begininvestigating.

Record your data at rest and after 1 minute of the activity. Then make a table to show yourfindings. Be sure to include titles for the columns and rows. Next, use your data table to createa double-line graph that shows both rates and what you discovered about the relationshipbetween breathing rate and pulse. Your conclusions should tell whether your prediction wassupported by the data.

Big Ideas and Unifying Concepts

Cause and effectChange and constancyForm and functionSystems

Life Science Concept

Structure and function

Science in Personal and Societal Perspectives Concept

Personal health



Mathematics Concepts

Data collection, organization and analysisGraphs, tables and representationsMeasurement

Time Required for the Task

Two or three 45-minute periods.

Context

My students had been studying the human body and its systems. We began with the circulatorysystem and investigated the heart and the purpose of blood. Students had also learned thatblood carries certain things that are required by cells, tissue and organs, such as nutrients,hormones, white blood cells and oxygen.

For this science investigation, I integrated a data-collection activity from our EverydayMathematics curriculum. This allowed students to apply their mathematics knowledge of datacollection and data display to our science unit on the human body.

What the Task Accomplishes

After studying the circulatory system, students understand that the blood transfers oxygen tocells for necessary functions. This investigation shows how the circulatory system is related tothe respiratory system. Students are able to apply their understanding of this relationship toactually investigating their own body systems. They are also asked to display their data in twodifferent representations.

How the Student Will Investigate

Students work in groups of two or three. We had a brief discussion about the task to get themthinking about the topic. Recording sheets provided some directions on how they wouldinvestigate the question. Each group had a stopwatch and was assigned to either a jump ropeor to the stairs. (Other possibilities might include running, doing jumping jacks or engaging inanother physical activity.)

Before beginning, students recorded their pulse rates while at rest. After they recorded theirpulse rates, they recorded their breathing rate for one minute. (The “timer” keeps track duringthe same time as the pulse is recorded.) Once students were in their groups, I asked the classto think about how well they were able to record their pulses. Could they record their breathingrate without thinking much about it? If so, then that person might want to be the “runner.”Another person, also good at recording, might want to be the "pulse keeper." The third personcould be the timer.



Then students went to their designated activity. One student completes the activity whileanother times it. Then the “timer” keeps the time for one minute, the “pulse keeper” records thepulse and the "runner/jumper" counts breaths. While students are performing the experiment, Imonitor the pulse and breathing rates that they are writing down. If the rates seem to be off(e.g., pulse rate of 25, breathing rate of 5), you might have them show you one of theirrecording sessions, or ask if you could see someone else’s pulse/breathing rate.

The students can then switch, so that the first student’s breathing rate returns to normal. Thesecond and third students can then complete the activity. Although the breathing rate and pulsemay not be recorded at exactly the same time, the results are similar and should not affect thegraphing piece of the task.

After recording results in their tables, students should try this experiment at least one more timeto ensure their results are accurate. They should then average their results. This might be agood place to break from the first class session.

During the second class, students can create graphs (with titles and keys). The most difficultpart of this that I found was the scale of “beats per minute.” Have the students look at all of theirinformation to determine the scale of the graph. By using a full piece of graph paper, divided byincrements of five, we found our information could fit. You may prefer to have students do twoseparate graphs, although then the relationship between the two lines may not be as obvious.

Interdisciplinary Links and Extensions

ScienceAfter completing this experiment, I found other examples of similar tasks. One variation was touse two separate graphs for pulse rate and breathing rate. Another was to time at morefrequent intervals, from rest to two minutes at 30-second intervals. The experiments did notimplicitly relate the two counts together but instead were done to show how one could monitorboth pulse and breathing rate.

Movement/MusicStudents could select different types/tempos of music and predict how moving to each wouldaffect heart and breathing rates. Most baroque music is very relaxing to listen to. It is oftenincluded in stress management programs because it can produce a heart rate of approximately60 beats/minute in the listener. Students could explore the effects of listening to different musictempos and compare them with or rank them related to “at rest” rates. Students could alsocollect heart-rate and breathing-rate data during a practice session for different sports ormovement activities.

MathematicsStudents can construct line graphs of data for different physical activities for the purpose ofcomparing and ranking. Students could determine and discuss differences in the “averagerates” for the class in terms of using the mean, median or mode.



HealthStudents can compare their investigation findings to research related to regular exercise,developing cardiovascular endurance and physical fitness.

Teaching Tips and Guiding Questions

Have all students measure their pulses at rest (in a classroom setting). Finding the pulse rateon the wrist is a bit harder but safer than using the neck. (If students press on both sides of theirneck at the same time, they could pass out.) Take some time to teach students how to find theirpulses. Explain to them to press lightly with the fingertips (not with their thumbs) on the outerside of the wrist. They can try counting for a full minute and then try a count for 15 seconds,multiplying it by 4, to verify.

Write the class results on the board. Notice that most resting pulse rates can range from75–100 beats per minute. Athletes tend to have slightly lower rates, due to conditioning. Somestudents will have a difficult time finding and recording their pulses but may see from the resultsof their peers that a pulse rate of 20, for example, is impossible! You may suggest that thosestudents either try it again or choose to be the timer in the experiment.

Calculate and write the average pulse rate of the class on the board so that students can referto it when recording their own data (not to use that information as their data, but to check theirsfor accuracy).

While students are working on their hypotheses, elicit information about what they know aboutboth the circulatory and the respiratory systems.

Ask:

• What does each system do for your body?• How does that relate to exercise? to fitness training?• What causes you to have a pulse?• What connection does the blood have to breathing and the heart?• How can you determine who will be the “pulse keeper” and “time keeper”?• What titles should be on your table? (You may need to review with the class what a table

should look like or refer to a previous experiment in which they made a table with the class.)• Using your data, can you explain whether or not your hypothesis was correct?• Look at your graph. What specific information can you find to back up your conclusion?• What proof do you have that can help you to now answer the question, “Is my breathing

rate related to my pulse?”• What would happen if you stopped exercising? (This may help them think about a rule to

connect breathing rate to pulse.) Encourage students again to think of the function of boththe respiratory and circulatory systems.



Concepts to be Assessed

(Unifying concepts/big ideas and science concepts to be assessed using the ScienceExemplars Rubric under the criterion: Science Concepts and Related Content)

Life Science – Structure and Function: Students use the terms pulse rate, breathing rate,respiratory system and circulatory system appropriately. Students identify characteristics oforganisms and understand that living systems demonstrate the complementary nature ofstructure and function.

Science in Personal and Societal Perspectives – Personal Health: Students develop anawareness that personal exercise, especially developing cardiovascular endurance, is thefoundation of physical fitness.

Scientific Method: Students describe cause-effect relationships with some justification, usingdata and prior knowledge. Students determine the patterns and/or which kinds of change arehappening by making a graph or table of measurements (change and constancy). Studentsobserve and explain reactions when variables are controlled (cause and effect).

Mathematics: Students use tables and graphs to show how values of one variable are related(pulse and breathing rate) to values of another. Students use numerical data and precisemeasurements.

Skills to be Developed

(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)

Scientific Method: Observing, predicting/hypothesizing, collecting/recording data, manipulatingtools, drawing conclusions, communicating findings and challenging misconceptions.

Other Science Standards and Concepts Addressed

Scientific Method: Students describe, predict, investigate and explain phenomena.

Scientific Theory: Students look for evidence that explains why things happen and modifyexplanations when new observations are made.

Life Science – Structure and Function: Students understand that the human organism hassystems for respiration, circulation, digestion, etc., which interact with one another. Studentsunderstand that living systems demonstrate the complementary nature of structure andfunction, including cells, tissues, organs systems, whole organisms and ecosystems.



Science in Personal and Societal Perspectives – Personal Health: Students understand thatregular exercise is important to maintenance and improvement of health and that personalexercise, especially developing cardiovascular endurance, is the foundation of physical fitness.

Scientific Tools: Students use computers to organize, analyze and interpret data.

Mathematics: Students use numerical data and precise measurements in describing events,answering questions, providing evidence for scientific explanations and challengingmisconceptions.

Suggested Materials

I had the following materials available for this activity: jump ropes, stopwatches, a space forphysical activity, graph paper and rulers. Students also had recording sheets.

I also suggest access to computers so that students can enter their data and create anelectronic graphic representation for the data displays.

Possible Solutions

The student should include a hypothesis, which states whether or not breathing rate is relatedto pulse. There should be some evidence of prior knowledge (of either the circulatory orrespiratory system). The data table includes columns and rows, labels and a title. Data forbreathing rate and pulse rate are for at least three time frames. The data are accuratelytranslated from the table and plotted on a graph (with title and accurate scale and labels for theaxes of the graph). There should be a key on the graph to distinguish the two lines.

Conclusions accurately compare the breathing rate to the pulse rate and cite evidence from thedata collected to support or refute the hypothesis.

The student gives a reasonable explanation of how s/he effectively used breathing rate, pulseand a stopwatch to measure these rates.

Note: I usually score this type of assignment (one having many different parts to it) with pointsgiven for each section. This approach is called analytic scoring rather than holistic scoring. I dothis because many students can have, for example, a solid hypothesis and then a weakconclusions section, or an incomplete data table. Then I look to see where the strengths lie andtry to weight the parts with the most important information a little more. This gives me the finalholistic performance levels: Novice, Apprentice, Practitioner and Expert.

Task-Specific Assessment Notes

NoviceThe student’s hypothesis is only a one-word answer, “yes.” It does not state any prediction orreasoning about breathing rate or pulse rate rising or falling. There is no evidence of knowledge



of the circulatory or respiratory systems. Data table and data collection are incomplete. Onlytwo time frames are recorded. The rates appear to be inaccurate, being that the pulse rate atrest is recorded as = 80 and after one minute of exercise, it is only = 30. Some columns androws have titles. Titles and labels are missing from the graph, although a key is included. Thescale and intervals on the graph are inconsistent. Data are plotted incorrectly on the graph.Conclusions do not show evidence of reasoning or conceptual understanding. Neither thecirculatory system nor the respiratory system is explained in the conclusion. There is onlylimited evidence of understanding the relationship between breathing rate and pulse.

ApprenticeThe student’s hypothesis states whether or not breathing rate is related to pulse. The data tableincludes a title and labels for the columns and rows but does not have data in chronologicalorder (from at rest to three minutes). The table includes data for breathing rate and pulse ratefor a minimum of three time frames. Data appear to be accurate and complete. A title and axeslabels are not included for the graph. No key is included. The intervals for each axis of thegraph are consistent, but the data are not shown correctly on the graph. Conclusions accuratelycompare the breathing rate to the pulse rate. This student’s solution is lacking in detail, in thatno specific examples from the data are used to support the conclusions. The student’sexplanation attempts to show reasoning but is not supported by data collected. The explanationdoes not show a cause-effect relationship and is not consistent with the available data.

PractitionerThe student’s hypothesis states whether or not breathing rate is related to pulse and includessome prior knowledge of the circulatory and the respiratory systems. The data table includescolumns and rows, labels and a title. The table includes data for breathing rate and pulse ratefor at least three time frames, recorded chronologically. Although a title is not included, labelsfor the axes of the graph are accurate (including measurement). The scale for each axis isappropriate for the data collected and is shown correctly on the graph. The data are accuratelytranslated from the table and plotted on the graph. A key is included on the graph to distinguishthe two lines. Conclusions accurately compare the breathing rate to the pulse rate. The studentclearly cites evidence from the data collected to support or refute the hypothesis. The studentgives a reasonable explanation based on available data.

ExpertThe student’s hypothesis (which states whether or not breathing rate is related to pulse) relatesthe respiratory system to the circulatory system. Examples show evidence of applying priorknowledge. The data table includes columns and rows, labels and a title. The table includesdata for breathing rate and pulse rate for three time frames, recorded chronologically. Dataappear to be accurate. A title and labels for the axes of the graph are included and accurate(including measurement). The scale for each axis is appropriate for the data collected and isshown correctly on the graph. The data are accurately translated from the table and plotted onthe graph. A key is included on the graph to distinguish the two lines. There is clear evidence ofscientific reasoning in the conclusion. Conclusions are supported by data. There is evidence ofextended thinking, such as what might happen when the person rests three to five minutes. Thedata trend is correctly identified from the graph and used to support reasoning.



Novice



Apprentice



Practitioner



Expert



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