I am a Novice Marathoner: Sources of Energy for the Big Race

Transcription

1 I am a Novice Marathoner: Sources of Energy for the Big Race Norliza Bt M.Yusof SM Sains Seri Puteri, Kuala Lumpur Mardiana Bt Yusof SM Sains Hulu Selangor Btg Kali, Selangor, Airin Bt Abu Bakar SM Sains Tuanku Munawir, Seremban Dr. Zaleha Abdullah Dr. Mahani Mokhtar Universiti Teknologi Malaysia For the teacher The lesson will bring students to a scenario of three novice runners preparing for a marathon. In a marathon, the production of energy during cellular respiration is important for muscles to contract. The concept, which the students will be learning is the expenditure of energy from cellular respiration and nutrition in daily lives activity. Energy is needed by a marathon runner to obtain energy supply from the body during the early time of the run. Students will be able to solve a problem on how to prevent hitting wall situation, which is depletion of glycogen source in the body during a marathon. The setting of this lesson can be done in a classroom or outside the classroom, to give students exposure in learning biology. They will be challenged to explain glycemic index (GI) and the use of energy during carbo-loading (for this lesson, students have to have prior knowledge on respiration and nutrition including assimilation). The objectives of the lesson are: a) To understand where does the human energy come from? b) To understand how the marathon runners get their energy for a long distance running. c) To understand which menus make a good meal before race for carbo-loading? d) To understand why food with high GI is not suitable to be eaten on the race day. The activities in this lesson include collaborative and active learning activities such as experimentation, drawing, discussions and brainstorming. There will be an animation of food digestion, absorption and assimilation. The students can watch another BLOSSOMS video, ATP: Fuel of Life to gain prior knowledge about ATP. Segment 1 Students are encouraged to find information on where does human energy come from and how do the runners get their energy during marathon. Students must have basic idea of 3 major food classes: carbohydrate, protein and lipid and teacher will ask the question: Where does human energy come from? 1

2 Activity 1 Students have to be divided into groups of three or four students in each group. They have to answer the following questions: a) Give 10 examples of food normally consumed by the students throughout the day. b) Classify the food into their classes.eg carbohydrate, protein and lipid. c) Discuss what you know about digestion and report back to the class? Segment 2 In Segment 2, explanation about where human energy comes from will be provided and an animation is used to explain basic idea on processes of digestion, absorption and assimilation of food to finally being converted to energy. Activity 2 Using the same group from the previous activity, students have to discuss about how the food that they eat moves around the body after it leaves the small intestine. Segment 3 Segment 3 shows the animation about how food is being absorbed and assimilated. After Segment 3, students must be able to explain glycogen stored in the muscle is used as energy supply. Students must be able to explain choice of suitable meal from given menu before race for carbo-loading. Activity 3 In the same group, students have to develop their own diagrams or flow chart about what they understand about the process from eating protein, carbohydrates and lipids in order to get energy for the marathon. Answering these questions would help them to develop their own diagrams/ flow chart: a) What are the products after carbohydrate, protein and lipid are digested? b) Where are the products being absorbed along the digestive tract? c) What will happen to the products after being absorbed? d) How many reasons can you list why carbohydrates would provide faster energy than proteins or fat? Segment 4 In Segment 4, students will be explained about the source of energy for long distance running which is glycogen and how glycogen is synthesized and supplied when marathon runners are in need of quick energy. Activity 4 Students have to discuss about the kind of diet that a marathoner should take on the days before running. This is a group activity and students have to report their answers in class. 2

3 Segment 5 Segment 5 tells students about carbo-loading and why carbo-loading is important for marathon runners. It also explains the form of energy storage in the body which is in the form of ATP. To learn more about cellular respiration and ATP, we suggest you to watch a Blossoms video on ATP entitled Fuel of Life to gain prior knowledge on cellular respiration and ATP. Activity 5 After figuring out the importance of carbo-loading, students have to identify the menus that make a good meal before race for carbo-loading. They will be given 7 menus to choose from. Segment 6 Segment 6 explained why specific diet/menu is associated with carbo-loading thus affect a runner s preparation for marathon. Students will also be learning about the glycemic index or GI; a value associated with a particular type of carbohydrate that indicates the food's effect on a person's blood glucose level. Activity 6 Based on a given graph, students have to analyze the graph of blood glucose levels against time to find out the relationship between the Glycemic Index and the rate of carbohydrate increasing glucose in the blood. Figure 1: Graph of Blood Glucose Change vs Time Students have to answer the following questions: a) Will you be able to choose food with a high Glycemic Index? b) Why is food with a high Glycemic Index not suitable to be eaten on the race day? 3

4 Segment 7 In Segment 7, students must be able to explain how the consumption of energy bars during running to overcome hitting wall condition. Students need to have prior knowledge on calorie and they have to explain the information listed on Table A and Table B. Due to health and safety caution, you can encourage the students to make their own energy bar at home to make the lesson interesting. Note: Teacher can carry out this activity for enhancement: Conduct an experiment to determine energy value of Nasi Lemak or Roti Canai. - Nasi lemak and roti canai can be replaced with suitable local dishes. - Suggested set up of apparatus and materials in this video is very basic and can be replaced according to availability of scientific Table A: Table B: Dried bananas 100 g 390 3,9 1,8 80,5 Dried briar fruit 100 g 110 3,4 0,0 21,5 Dried fruit caloric table Dried dates Product 100 Quantity g 277 Energy (kcal) 2,0 Protein (g) 0,4 Fat (g) 74,0 Sugar(g) Almonds Dried figs 100 g ,0 3,6 52,0 1,2 20,5 78,0 Cashews Dried peach 100 g ,2 3,0 53,6 0,4 12,6 57,7 Cedar Dried pears nuts 100 g ,0 2,3 61,0 0,6 12,0 62,6 Coco Hazelnuts 100 g ,4 14,4 33,5 63,0 29,5 14,9 Dried Hazelnuts apples 100 g ,1 16,1 2,1 66,9 62,3 9,9 Dried Mustard apricots pits 100 g ,4 25,8 1,2 30,8 72,2 23,4 Dried Peanuts apricots with stone 100 g ,0 25,7 0,0 46,1 53,0 19,2 4

5 Pecans 100 g ,5 48,5 25,0 Poppy seeds 100 g ,1 42,9 24,7 Prunes 100 g 267 3,5 1,2 68,9 Pumpkin seeds 100 g ,5 45,8 18,0 Raisins 100 g 277 2,3 0,5 71,2 Roast chestnuts 100 g 182 3,2 2,2 33,8 Sesame seeds 100 g ,4 48,7 12,2 Sunflower seeds 100 g ,4 43,7 24,6 Walnuts 100 g ,0 60,3 18,0 Activity 7: From the given Table A and Table B, students have to mix and match ingredients of their recommended energy bar for marathoners. Choose from the three categories Cereal, Dried fruit, Nuts and extras. They will have to follow instructions given by the teacher and design their own energy bar for marathoner. They will also have to explain on the relevance of the ingredients used in their energy bar. 5

6 If the activities require longer time, this video can be divided into several lessons. For example, Segment 1 to Activity 4 covers in the first class lesson; and then, segment 4 to segment 7 in the next class lesson. Note: For teachers who would like to carry out an enhancement, below is a suggestion. Samples (adult age 21 years to 35 years old) are selected few days before the experiment. They are required to fast for hours before conducting this experiment 1. In this video, there are four groups of samples. 2. Each group is given: 100ml glucose solution, 50g roti canai, 50 g nasi lemak, glucometer, alcohol swab and stopwatch. 3. The students must eat 50g Roti Canai. Start the stopwatch. 4. Determine level of glucose in the blood in 30 minutes interval using glucometer. The experiment is conducted for2 hours. (Note: Refer to Note A, on how to use the glucometer). 5. Tabulated the data and plot a graph of blood glucose level against time. 6. Repeat the experiment the next day using 100ml glucose solution and 50 g nasi lemak. How to use a glucometer? 1. Test the glucometer before using it. 2. Most glucometers include a way to test to make sure they are reading correctly. This could be in the form of a premade test strip or a liquid you place on a test strip. 6

7 These are inserted into the machine and the reading should be within acceptable limits. 3. Wash your hands thoroughly, including the area from which you are going to draw blood. 4. Most diabetic glucometers instruct you to prick your finger for a sample, but some of the newer blood glucose meters let you use an area on your arm. Determine which of these areas is acceptable for your meter. 5. Place alcohol on a cotton ball. 6. Place a test strip into the slot provided on the glucometer. 7. Swab the area you are going to use to draw your sample from with the cotton ball. 8. Alcohol evaporates rapidly so there's no need to dry the area. That will just recontaminate it. 9. Wait for the readout on the diabetic glucometer to tell you to put the drop of blood on the strip. 10. The readout may actually say "place sample on strip," or it may give you a symbol, such as an icon that looks like a droplet of liquid. 11. Use the lancet provided with the diabetic glucose meter and prick the area for the sample. 12. Lace a drop of blood on the test strip. 13. The newer strips offer a "wicking" action that will draw the blood up into the test strip. Older meters and strips require you to actually drop blood onto the strip. 14. Most diabetic glucose meters require no more than a drop of blood to test. 15. Wait for results. 7

8 16. The meter will begin a countdown in seconds once the sample hits the strip and the meter detects it. For newer meters it will be 5 seconds, older meters could be 10 to 30 seconds. The meter will sound a tone, or beep, when it has a reading for you. 17. Read and record your results. 8