A waste product of respiration is carbon dioxide. This is left inside the cells after the chemical reaction of aerobic respiration has occurred. The carbon dioxide diffuses out of the cells and into the plasma of the blood. From there it will be pumped around the body by the heart until it enters the capillaries where it will diffuse into the capillaries. This is then released back into the air when we breathe out.
http://upload.wikimedia.org/wikipedia/commons/thumb/8/8b/Alveoli.svg/800px-Alveoli.svg.png
This graph shows how our bodies will require more oxygen during exercise. There is an increase in both heart rate and breathing rate throughtout the exercise and both reach there peak at 15 minutes, just before the excercise was stoped at 15 minutes. After the excercise was stop both heart rate and breathing rate beging to decline back to there originial, ‘resting’ rate and both have nearly reached this by 25 minutes.
Theres is an increase in breathing and heart rate becasue the oxygen that is in the red blood cells will be being constantly used up to create energry so oxygen will be constantly diffusing into the cell. This will deplete the ammount of oxygen in the blood so oxygen will also be constantly be diffusing from the alveoli into the blood.
The blood in the alveoli enters when we breathe out and that is why our breathing rat eincreases. Our heart rate increases to pump the blood around th ebody faster so that gas exchange can occur at an increasing rate.
This means that oxygen will constantly be diffusing into the respiring cells because it is constantly being used up. It is constantly being used up as our body requires more oxygen during the exercise.
We ensured the data collected in this experiment was valid by keeping it a fair test. To make the test fair we kept conditions throughout the repeated exercise the same such as temperature and no participant was allowed food or drink while participating in the experiment. We used a metronome and stop watch to ensure that ensure that everybody exercised for the same amount of time and at the same rate. We also took the results at the same times for each experiment; this allowed all but one variable to change and make our results to be as valid as possible. We also ensured the data was reliable.
To make the data the data reliable we repeated the test on different students and found the average. We also checked all the individual results to make sure they were concordant to eliminate any mistakes.
We could have made the data more valid by using a digital heart rate and breathing rate monitor which would have provided a continuous stream of data and eliminated any human errors, however the techniques we used in this experiment were adequate to provide us with valid results.
Exercise is known to have numerous benefits on the human body.
A person with a high level of fitness regulates their cardiovascular system more efficiently. This means they can increase the concentration of red blood cells in their blood which allows them to hold more oxygen at a single point meaning their heart rate can be reduced - their heart will be stronger and more efficient at pumping blood. A fit person can also increase the efficiency of gas exchange in the lungs so their breathing rate can also be reduced.
The secretion of the digestive juices is stimulated by exercise meaning that digestion becomes more efficient. Exercises also stimulate the intestinal movements, resulting in more effective elimination of wastes.
Regular exercise strengthens the muscles, promotes their development and increases their efficiency. Stronger muscles lend better support to the joints. The pores of the skin open up during exercise. The result is a healthier skin, because of more efficient disposal of impurities and dirt and the temperature of the body also rises during exercise. This promotes the burning up of the toxic substances in the body.
Adapted from http://www.healthguidance.org/entry/4349/1/Advantages-of-Exercise.html
Exercise also has physiological benefits as well as physical. Exercise is known to be a mood enhancer. Exercise stimulates the release of endorphins in the brain which are believed to relieve pain and reduce stress
“Exercise is good for the heart because it encourages new blood vessels to grow to supply muscle fibres and ultimately switches the muscles into aerobic metabolism. Unlike anaerobic metabolism that uses sugar for energy, aerobic metabolism breaks down fat for energy.”
Source: http://news.bbc.co.uk/2/hi/health/3992413.stm
“No matter how much attention you pay to your diet, you are at risk of a heart attack if you don't exercise. Lack of exercise is the single worst risk factor for heart disease for both men and women.”
http://www.netdoctor.co.uk/hearthealth/exercise.htm
When our bodies cannot obtain enough energy through aerobic respiration, our cells undergo the process of anaerobic respiration. This causes the production of lactic acid which is a harmful toxin that when excessive build up occurs, can cause cramps.
Glucose → Lactic Acid
An unfit person is more likely to require their cells to undergo the process of anaerobic respiration as well as aerobic respiration as the cardiovascular system is less efficient that a fit persons.
Their cardiovascular system being less efficient means that during exercise their respiring cells will not be able to produce as much oxygen in the same period of time as a Fit person because the unfit person cannot take in as much oxygen at one time and there heart is also weaker and less efficient at pumping blood around the body.
Source: http://hsc.csu.edu.au/pdhpe/core2/aerobic/4-2/resting_hr.gif
This graphs shows how an unfit person will have to increase their heart rate to a greater speed than a fit person while doing the same exercise to achieve the same production of energy.
This can cause possible detrimental health effects to unfit people. It is possible to have a heart attack from over exercise and it is possible to sustain injuries such as strains, sprains and torn ligaments if proper warm ups are not implemented. Running and jogging can cause damage to knees and ankles if a person is unfit and has a poor diet meaning there bones are lacking in strength.
Exercising for the incorrect reasons can also be damaging to mental and physical health. Exercising with the aim of becoming underweight can deteriorate mental and physical health along with the possible risk of injecting steroids to gain advantage.
If your somatotype is 'ectomorph' it is possible that prolonged periods of exercise will actually have a detrimental effect on your body if you do not eat a balanced diet and consume enough carbohydrates.
Also, exercise dehydrates you so it's important to make sure you stay hydrated and if you're asthmatic it can put extra strain on your lungs and trigger attacks.
In conclusion I would still strongly recommend exercise as I the benefits listed above far outweigh the negative side effects it can have. If exercise is undertaken responsibly it is unlikely that these side effects will occur. Proper warm up and cool down procedures should be more widely publicised to reduce the risk of sustaining injuries such as strains, sprains and torn ligaments.
