EXERCISE AND HEART RATE OBJECTIVE: To observe any changes to the heart rate (pulse rate) before, during and after exercise. MATERIALS & APPARATUS: Yourself; stop watch (or anything with a timer); someone to help you time BACKGROUND: Heart rate is a term used to describe the frequency of the cardiac cycle. Usually it is calculated as the number of contractions (beats) of the heart in one minute. As such heart rate is usually expressed as "beats per minute" (bpm). The average teenager’s heart rate varies between 70 to 100 bmp. The pulse is one way of measuring the heart rate. Heart rate measures how fast your heart is beating and is the number of heart beats per minute; the times per minute that the heart contracts. Average heart rate is the average of heart rates measured during an exercise period. Recovery time is how long it takes for the heart to return to its normal resting rate after physical activity. METHOD: Locate your pulse on either your wrist or your neck. Sit quietly for a few minutes until you are completely at rest. Have someone help you with timing and count the number of heart beats (your pulse) for 1 minute. Record this value. Wait 1 minute and then take your resting heart rate for another minute. Record this value. Do some form of VIGOROUS exercise for 2 minutes. Immediately measure your heart rate for 1 minute. Wait 1 minute and record your heart rate for another minute. Continue this until your heart rate returns to close your preexercise/resting rate, and you get 2 consecutive readings that are very close together. Record all these values. You will present your results in the form of a table showing minute against heart rate. You will also show your results with a line graph. You will then write a Discussion for this activity explaining your results. Use the question provided as a guide as to what your discussion should include. DISCUSSION QUESTIONS: (these questions are here to guide your discussion. I do not want just the answers to these questions but a discussion explaining your results using these questions as a guide. 1. Why is it important for the heart to pump blood around the body? 2. What does the body need for exercise? Through what process is this made? What is needed for this process? 3. How does your heart rate change with exercise? (use you actual data to show how your heart rate changed) 4. Why does this change take place? Why does your body respond to exercise in this way? 5. What was your recovery time? What factors could affect a person’s recovery rate? 6. Why does your heart rate take a while to return to its resting rate? Why is there a recovery time? 7. What is an oxygen debt? What is built up in them muscles when we need more energy and use more O2 than the body can supply? YOUR LAB REPORT: This report can be either hand written or typed up but your graph needs to be on graph paper. You will hand up your lab report in class on Thursday 14 th October. 1. TITLE 2. AIM/OBJECTIVE 3. MATERIALS & APPARATUS 4. METHOD (written in past tense and in simple steps) 5. RESULTS – table and line graph (see below for rules for tables and graphs); work out your average resting heart rate, your recovery time, by how much your heart rate changes after exercise 6. DISCUSSION – you should have at least a couple of paragraphs – use your actual data to relate your discussion to your activity 7. CONCLUSION – a simple sentence that links directly to your aim/objective that states what your activity showed. RULES FOR TABLES AND GRAPHS: 1. Each must have a suitable title written in capital letters and underlined 2. If drawing by hand, use pencil and rulers 3. Use the whole graph paper for drawing your graph 4. Use a suitable scale and write the scale that you used (e.g. 1cm represents 1 minute; 2cm represents 20 bmp) 5. Label each of your axes of your graph (time in minutes; heart/pulse rate in bmp) 6. Please use a ruler to connect your points