Most cells in the body need oxygen to function correctly, when we exercise the cells need more energy and oxygen so that the muscles which help us to complete the exercise can move by muscle contraction. The energy which we need for muscle contraction comes from food molecules inside cells, this is a process which is known as respiration. The main respiratory substance is glucose and the energy released is used for the muscle contraction that we need to exercise. When we do anything are body is releasing energy to help us to fulfil what we are doing. Even the simplest actions need energy. When we start to exercise we use aerobic respiration, this takes place in the presence of oxygen, and most of the energy released in this process is released in the mitochondria. This respiration can be summarised as:
Glucose + Oxygen Water + Carbon + Energy
C6 H12 O6 +6O2 6H2O + 6CO2
The amount of energy released during aerobic respiration is roughly 38ATP.
During exercise some cells are not supplied with enough oxygen to meet their energy needs. At this point cells respire lactic acid aswell this can be summarised as:
Glucose Lactic acid
C6 H12 O6 CH3CHOHCOOH
The amount of energy released in anaerobic respiration is much smaller in comparison to aerobic respiration, roughly only 2ATP. Anaerobic respiration only releases a small amount of energy and produces lactic acid. (This is the burning like feel you have in your muscles when you do vigorous exercise and sometimes turns into cramp or stiffness.) Anaerobic respiration only takes place when there is not enough oxygen. Anaerobic respiration takes place in the cytoplasm of cells. Oxygen is needed to remove the lactic acid this is shown as: Oxygen
Lactic acid Water + Carbon Dioxide
O2
CH3CHOHCOOH H2O + CO2
This is commonly know as borrowing energy without paying oxygen. Hence oxygen must be repaid therefore the person will breathe deeply for a while after the exercise this is known as the recovery period.
Prediction
I predict that during exercising the heart rate will increase dramatically because the heart is working harder to pump the oxygenated blood around the body. So the oxygen can get to the cells so energy can be released during respiration for the muscle contraction we need to exercise. This also refers to the information about respiration in the introduction.
Variables and a fair test.
I will make the experiment a fair test by repeating the experiment 3 times to allow for any anomalous results. By repeating the experiment three times I can take the average of all the results and the results will be more precise. My controlled variable, the variable that I will keep the same would be the type of exercise that we would complete also the equipment that I would use, the lap top data logger etc. My independent variable
Apparatus List
A lap top computer with the correct software for the use of a data logger.
A data logger which can be programmed to record heart rate every 30 seconds.
A stepping machine set to level 2.
Method
- Find an empty space where you can set up an exercise machine and a lap top.
- Attach a data logger to the computer and pre-set it using the software so that it will record your heart rate every 30 seconds.
- Remove the data logger from the computer and attach it to yourself.
- Take your heart rate while you are resting.
- Now start to exercise on the stepping machine. Keeping the movements constant.
- Throughout the exercise period the data logger will be measuring your heart rate every 30 seconds.
- After you have completed 5 minutes of exercise stop exercising.
- The data logger will measure your heart rate every 30 seconds until it returns to it’s resting rate, the rate it was before you started to exercise.
Results
1st set of results
The spare rows are to be used to put heart rates in after you have finished exercising they should continue until your heart rate has returned to normal.
NOTE: You may need to add more rows.
2nd results
3rd results
Hopefully by gaining a full set of results we will be able to put together a graph or pie chart, like the examples below. Remember this is only an example and does not show any true results. Not to be used as evidence of true heart rates.
