Glucose Lactic acid + Energy
With a large build up of lactic acid it will, along with time, come away from the muscles. A fit person will not build up an oxygen debt so their muscles respire aerobically. (From schools GCSE booklet.)
During exercise the heart beats faster and this is due to the extra carbon dioxide that is produced by the muscles and this starts to build up in your bloodstream. The brain senses that this is happening and it sends nerve impulses to the heart making it beat faster. This is an automatic response.
The result is that the heart is beating faster and that more blood can be sent to the muscles. The arteries serving the muscles widen, whereas those serving less needful organs become narrower. The result is that extra blood is diverted to the structures that most need it.
I believe that this is true from my preliminary work I did an experiment which compared inhaled and exhaled air before and after exercise. This involved using limewater, which in the presences of carbon dioxide will turn cloudy. I found that after exercising for 1 minute turned the limewater cloudy in 7 seconds, whereas when I hadn’t exercised it took 22 seconds for the limewater to turn cloudy. This concludes that we breathe out more carbon dioxide when we exercise because we are using much more oxygen to help the muscles work so wee need to breathe out carbon dioxide. (From “Biology for Life” by M.B.V. Roberts).
Also from secondary sources I believe that this is true because from schools GCSE booklet and in “Biology For Life” it states that during exercise the heart beats faster due to the extra carbon dioxide that is produced by the muscles and starts to build up. Also people are breathing much faster and need to remove the extra carbon dioxide more quickly otherwise it will build up and poison our tissues.
Variables
The possible key factors to vary are:
- The type of exercise that is carried out,
- Length of exercise,
- The intensity of exercise,
- Age of the person,
- The Gender of the person,
- The surrounding temperature which the experiment is carried out,
- If the person has any medical problems i.e. asthma.
I have decided not to use some of the variables above here are a few possible reasons why.
- Gender of the person would only give two sets of results and a range would be better.
- The age of the person as this would give on set of results as everyone in the class is the same age and it’s not practical.
- Intensity also because it is very difficult to measure intensity and it’s not controllable.
Readings
- I am going to repeat the experiment three times as this will give accurate results as the first procedure my have done wrong i.e. Human error with readings of pulse, breathing rate etc.
- I will average my results, as this will also to give reliable and accurate results, as this will also help any mistakes.
- Also the person who will do the excise will be the same as people are fit and unfit and the results will not be accurate.
- After exercising the person should take a rest to slow breathing and heart rate down and also to cool down.
Apparatus
Here is a list of apparatus, which will be used in the experiment:
- Stopwatch
- Forehead thermometer
- Drink
Safety
- All stools should be underneath the desks if any form of exercise is to be carried out safely.
- Don’t exercise if you have any health problems.
- Keep a drink to stop dehydration.
- Do the experiment under supervision of a teacher in case of an emergency.
- The person will carry out the exercise in suitable footwear i.e. trainers so that this person will not injure their ankles.
Fair Test
I will make this experiment a fair test by:
- I will change the amount of time doing exercise; I will use the same person to do the experiment.
- I will use another person to take the pulse and use the same person to take the pulse each time.
- I will make sure that the person will start exercising on the same resting pulse rate.
- I will get the same person to take the time while I exercise.
Plan
1.) Collect all equipment needed for the experiment.
2.) Take all readings for heart and breathing rate and skin temperature and time with a stopwatch for a minute.
3.) Now begin the exercise for one minute. Record the pulse and breathing rate and the skin temperature. Now repeat twice and record your results.
4.) Now let the person rest to take pulse and breathing rate down.
5.) Begin to exercise for two minutes and then take all readings repeat twice.
6.) Repeat the procedure for three, four and five minutes making sure that you take three readings for each period of time. This will make sure that my results will be more reliable and more accurate.
7.) Always time the reading of pulse and breathing rate for one minute.
8.) Take the averages of the three readings for reliable results.
Results
Heart Rate Breathing rate Skin Temperature
Patterns
I took averages of my results as this would help with any mistakes, which may have happened during the experiment i.e. Human error. On my graphs I drew a line of best fir to show how my results followed any patterns and trends.
In general you can see looking from the graph that the heart rate increases. At the beginning the heart rate began rapidly but towards the end it seemed to slow down. The length of time is proportional to the heart rate. The graph shows that the heart rate didn’t increase a huge amount for the first minute but then increased very steeply for most of the rest of the exercise. However, during the final minute the heart rate doesn’t increase much at all. This happened because the supply of Oxygen to the muscles decreased, a lot of energy will be used up as the exercise took place, the body was unable to continue aerobic respiration and anaerobic respiration took place. This resulted in lactic acid being formed. Finally, the Carbon dioxide levels also rose which also contributed to the heart rate rising.
Breathing rate definitely shows an increase as the graph indicates a rapid increase in the first few minutes. It the gradient is steeper and it roughly goes up twos and threes so time is inversely proportional to breathing rate. You can see for the first few minutes of exercise that the breathing rate didn’t increase by a huge amount but then increased very steeply for the rest of the exercise.
The skin temperature shows that there was an increase but the graph does not show steep increase. There are a few anomalous results, as the temperature didn’t increase quite sufficiently. The graph doesn’t show how accurate the results were.
From looking at my graphs also you can see that there was a greater increase in the heart rate than any of the other factors. This shows that during exercise that the heart works a lot harder in pumping the blood around the body keeping the muscles supplied with oxygen whilst removing the carbon dioxide. The gradient is a lot steeper for the heart rate graph showing that during the exercise the heart is under great pressure and strain so that the body can function properly and that it has to work the hardest during exercise. This shows the heart is working even harder during longer periods of exercise and much faster as the graph shows the steep gradient.
Conclusion
From my looking at my results I have found out that when a person exercises for a longer period of time their heart rate will increase and so will your breathing rate. Your skin temperature will also increase and as a result of exercising respiration will increase. From looking back on my predictions I can see that my predictions were correct that the breathing rate, heart rate and the skin temperature increased when a person exercises for a longer period of time.
Respiration will increase because you need more oxygen and glucose for respiration and your muscles are respiring too and you need the energy to keep exercising. The energy released from glucose in respiration is used to produce chemicals such as adenosine triphosphate (ATP). It is thought that there is a link between the breakdown of glucose and the contraction of muscles.
During exercise lactic acid builds up in your body. Lactic acid is a mild poison and it causes our muscles to ache. When the exercise is over we have to get rid of it. This is done by breaking it down into carbon dioxide and water. Oxygen is required to get rid of lactic acid is called the oxygen debt. If we incur an oxygen debt during exercise, we must repay it off immediately afterwards. Because the muscles can work for a short time without oxygen.
During long periods of exercise lactic acid builds up to begin with, but later is removed while the person is exercising.
Anaerobic respiration produces far less energy than aerobic respiration and it cannot go on indefinitely.
When the breathing rate increased this was because our muscles working harder so they need a larger supply of oxygen. Also extra carbon dioxide, which was produced, was removed more quickly, otherwise it might build up and poison our tissues.
It was the sense in the brain that detected there was too much carbon dioxide in the bloodstream which automatically causes us to breathe faster.
We do not just breathe faster-we also breathe more deeply. In this respect there is a difference between fit and unfit people: fit people tend to breathe more deeply when they take exercise; unfit people tend to breathe more quickly, keeping their breathing shallow. Looking at my graphs you can see that the person, which carried out the experiment, was reasonably feet as you can see the breathing rate only increased considerably and then they began to breathe at a constant rate. If the graph were to be carried on four a longer period of time my graph would show this.
The energy that is released for movement energy and the rest is used as heat energy this why your body temperature increases.
When you exercise your heart rate increases because the heart has to supply the blood faster and the oxygen, which is why your heart rate has increased. If the heart didn’t supply enough oxygen and didn’t beat faster the muscles are deprived and they therefore carry out anaerobic respiration.
During exercise your heart beats faster due to the extra carbon dioxide produced by the muscles and this starts to build up in your bloodstream. The brain senses this happening, and sends out nerve impulses to the heart making it beat faster. This is an automatic reflex.
The result of the heart beating faster is that more blood can be sent to the muscles. The arteries serving the muscles widen, whereas those serving less needful organs get narrower. The result is that extra blood is diverted to the structures that need it most.
Breathing increases as the oxygen is needed in respiration and for movement. The body has to get enough oxygen into the body faster and remove carbon dioxide. The oxygen is then pumped around the body where it is used.
The body temperature increases during exercise because of the result of the process metabolism, by which foodstuffs are converted into protein, carbohydrates, and fat, with the release of energy in the form of heat. Because active muscles metabolize food faster than muscles at rest, giving off more heat in the process, physical activity increases the body temperature. One form of physical activity, shivering, activates certain muscles to increase metabolism and thereby warms the body.
Once the body temperature reaches its maximum various regions of the body are controlled to cool down the temperature down. This is done in various ways.
The hairs on the arms are lowered by relaxing the erector muscles. As a result the hairs lie down flat and air is no longer trapped between them so more heat is lost easily from the body.
Also the blood vessels on the surface of the skin widen so that more blood flows through them, and heat is lost as t flows close to the surface.
Our skin gets covered with sweat and, which is secreted by the sweat glands. When the sweat evaporates, it cools the skin and the blood flowing through it. This also relates to what was stated in my prediction, as what I originally predicted was correct. (From “Biology for Life” by M.B.V. Roberts).
Evaluation
From the experiment I obtained good results and I found the experiment most enjoyable. The apparatus was simple and easy to use and gave me reliable results. There weren’t many problems only with measuring the pulse rate and breathing rate. There were many times when you couldn’t find a pulse fast enough allowing the heart to rest, which will have affected some of our results. Also the pulse mist beats, which were found hard when counting, as the heart seemed to be beating faster having too many beats. The measuring of the breathing rate was also difficult as breaths were mist and also how deeply you were breathing. The experiment was safe and the plan was followed and a safe procedure was carried out. The method was well planned and carried out correctly and only a few points were changed due to the surroundings where the experiment was carried out. We had to change the type of exercise from jogging on the spot to actual running of the corridor as we found that there would be a definite increase in the heart rate. We obtained 9 sets of results from this experiment showing the effect that exercise has on the body. Our results were accurate and I did only find a few anomalous results as shown by the graph for temperature. As you can see from the graph there were a few results, which did not fit into the line of best fit, but on the temperature graph there were a few eccentric anomalous results which was sue to the temperature not increasing proportionally and increasing at different periods of exercise. The results for the experiment we correct to the nearest whole number due to the fact that we did not have the sufficient equipment to measure the heart rate and breathing rate correct to one decimal place. All of my experiments were repeated three times and then the results were averaged to give more reliable results. This made sure that if there were any inaccuracies my results could be compared and then average to give more accurate results, this also stopped any anomalous results. The results were reliable and proved that my prediction was correct and this proves also that the experiment was carried out correctly.
The results were reliable although there were a few results, which did seem not be correct and there were a few errors. This could be due to human error counting the pulse rate wrong, counting the number of breaths wrong, and also using your thumb to measure the pulse, this would have meant you were counting your own pulse. Also the intensity of the exercise might not have been the same so the results didn’t fit the patterns. Also the skin temperature our body has cooling mechanisms when the temperature increases and cools the body down. The body does this by sweating and the temperature will decrease, this is why our results may have anomalous. Also the surrounding temperature of the room may have affected our body temperature if it was too hot or too cold. Skin temperature we found that the temperature didn’t increase that much only by one or two degrees which on the graph there isn’t much of an increase. The heart rate also as we found that the heart sometimes would beat slower and faster. In my opinion the results become less accurate the longer the length of exercise as this had a much faster pulse and breathing rate and it was very difficult for a person to count and this may have produced some inaccurate results. Also as I have already mentioned the skin temperature our body has cooling mechanisms when the temperature increases and cools the body down. The body does this by sweating and the temperature will decrease, this is why our results may have anomalous. Also the surrounding temperature of the room may have affected our body temperature if it was too hot or too cold. This meant that the temperature readings were incorrect, but these problems are all possibilities.
These problems could be overcome by using machinery, which could measure the heart rate accurately, and breathing rate could make further improvements to our results. Temperature probes could be used as they give more accurate temperature readings and this would have made great improvements. The temperature of the room could be kept constant by using a thermostat, as this would not affect the body temperature therefore more accurate results. The type of exercise could be changed to something simpler or a more intense exercise. Therefore this would stop any anomalous results and I could have more reliable and accurate results to draw conclusions from. If I were doing this experiment again I would have to look closely at the method of exercise I used. I think that exercising on a piece of equipment like a running machine would produce more accurate results because I would be able to guarantee that the exercise remained constant throughout this experiment.
Finally, an actual ‘pulse-meter’ might have helped the experiment to be more accurate. This is simply strapped round the chest of the exercise and it measures your current heart rate. I believe that this would produce a more accurate heart rate and destroyed any necessity to have the 30-second breaks during the exercise.
The conclusions I have made are true for variables tested in my experiment (breathing rate, heart rate and skin temperature). There is sufficient evidence to support a firm conclusion but further experiments would need to be carried out to prove that my conclusions were true. I cannot say for sure that as the heart rate increases it is proportional to the length of time, and that the breathing rate and skin temperature increase during exercise and after certain periods of time becomes constant as further experiments would need to be carried out. Further variables could be taking the experiment outdoors could this affect the heart rate or the body temperature. Doing the exercise for an even longer period of time could the heart rate level after so long or could it keep on increasing. If the body works for longer will aerobic respiration last or will the person carry anaerobic respiration and build up lactic acid. These are some the changes which could be done to improve the experiment.
I would also use accurate measuring equipment so that no errors occur and good, clear accurate results are obtained. The good results would present a clear idea of what effect exercise has on the body.
