Respiration is the process that releases energy food. In this process Glucose from our food is oxidised to give, carbon dioxide, water and energy is released in form of ATP.
The overall equation for respiration is:
C6H12 + 6O2 6CO2 + 6H2O + ATP
Effects of exercise
As a person exercises, the longer the person exercises the dept of breathing increases as the exercise becomes harder or tiring. Our lungs respond to this by increasing the breathing rate (air inhalation). So, lungs could supply more oxygen from air, which is then transferred from the lungs through alveoli to the blood and then to the muscles via the circulatory system. During strenuous exercise, as the exercise get harder or more tiring, the demands for oxygen cannot be met alone by respiratory organs. During this time ‘anaerobic’ respiration takes place. This process builds of an oxygen deficit, during which lactic acid is produced. After the exercise, at rest the subject (person) will continue to breathe hard and the heart rate remains the same, until the body has paid back the oxygen debt to the muscles. The oxygen is used to convert the lactic acid back to glycogen.
The effect of exercise on breathing is measured by calculating the ventilation rate. This is the total volume of air moved into the lungs in one minute. The ventilation rate is calculated as follow:
Tidal volume * breathing rate
Tidal volume is the volume of air breathed in and then simultaneously breathed out during a single breath.
The aerobic fitness is a measurement of the uptake: transport and use of oxygen by the body. An indicator for this is Vo2 max, which is expressed in dm-3 min-1 or cm3 kg-1 of body mass. This is the maximum rate at which the body absorbs and make use oxygen. Aerobic fitness is measured by having the subject perform strenuous exercise for example, running on a treadmill and then gradually increase the intensity of the exercise, at the same time taking measurement of the subject oxygen uptake. As the intensity of the exercise increases the uptake of oxygen will also increase. The better a persons aerobic fitness is, the higher the intensity of the exercise at Vo2 max (Aerobic fitness and its significant – Internet site). This is saying that if a person has high Vo2 max, the more work this person can perform. This measurement of aerobic fitness is quite complex and needs to be carried out in a laboratory, as it will need relatively expensive equipment. The other way, which is easier to make measurement of aerobic fitness, is to take measurement of the subject heart rate. This is good a indicator, because oxygen is delivered by the circulatory system and each heart beat indicates a quantity of blood being pumped by the heart.
Heart rate is affected by age, gender and fitness level of a person. In young people heart rate is higher than older people. This is because young people can increase their heart rate and deliver large amounts of oxygen to the muscles, which is why they have better aerobic fitness than older people. Older people seem to have lower heart rate, which is a major cause of their reduced aerobic fitness. The other reason for this is that older people generally have less muscle mass and more body fats. This is not necessarily true; a person could improve his/hers aerobic fitness by regularly training their body. By regularly exercising improves the transport of oxygen efficiently within the body. This is because by exercising you train your heart to lower the heart rate- at lower heart rate the heart pumps more blood with every single heart beat. This and other physiological changes like reduction in body fats increase the oxygen transport capability. Thus, I will need to consider these facts in my investigation.
Effects of smoking on the cardiovascular systems
Carbon monoxide inhaled by smokers increases the CO level in the blood. Haemoglobin in the red blood cells helps transport oxygen from heart to rest of the body including working muscle. As CO has greater affinity for haemoglobin than does oxygen, this means that CO from smoking will readily bind with haemoglobin and prevent oxygen from binding to haemoglobin. Also, myoglobin in the muscles works same as the haemoglobin in the blood, thus less oxygen from blood gets to working muscle due CO occupying the haemoglobin and preventing oxygen molecules reaching the muscles. Research shows that smoking reduces maximal oxygen intake known as VO2 Max and causes premature muscles fatigue. Therefore, I find that smokers will have less aerobic fitness than non-smokers. Exercise triggers sympathetic nervous system to release epinephrine and increases heart beat as well as blood pressure. But, nicotine decreases responses to epinephrine.
Smoking and health
Cigarette smoking kills many thousands of people a year, making it the largest preventable cause of death in developed country (National Cancer Institute). Smoking increases the risk of coronary heart disease and heart attacks five times the normal risk. This occurs as a result of atherosclerosis in the lining of the coronary arteries that makes them to become narrow and restrict the flow of blood. This forces the heart to work extra hard to force blood through the coronary arteries and causes blood pressure to rise. Consequently less oxygen and nutrient are supplied to the heart muscle during vigorous exercise.
Cardiovascular diseases are cause of many factors like diet and smoking. Nicotine is one of the major factors that increase the blood pressure by constricting the arteries (Jones 2000 and A/S Biology). This rise in high blood pressure damages the lining of arteries. This damage promotes the development of fatty plaques and blood clot. Making it difficult for blood to flow through the arteries and eventually flow of blood will be completely reduced.
Smoking also increases the risk of emphysema and lung cancer due to build up of tar form cigarette smoke in the lungs. As the diseases emphysema progress the blood vessel in the lungs become more resistant to flow of blood, raising blood pressure in the pulmonary artery. Hence, this reduces the ability of blood to transport oxygen effectively to muscles for respiration to take place.
Method
To find how heart rate and blood pressure is affected by exercise in both smokers and non-smokers. I could use variety of equipment to carry out this investigation. Treadmill can be use to carry out the exercise or I could use a simpler equipment like stairs or a step, which is much cheaper than a treadmill and would give me the reading that I need to acquire. However, it would be better to use a treadmill, if you taking measurements of heart, lungs volume during exercise and including various other physiological reading are being taken as well. As I will need only heart rate and blood pressure it is best to use a lesser complex equipment. So I will use a step to carry out the exercise, because using a step you could carry out the experiment at home or at college. Also, that our college don’t have a treadmill, thus I will need to hire one or use an external source.
Equipment that I will be using
- Step
- Digital sphygmomanometer – to take reading of blood pressure
- Stop watch – to measure exercise time
Procedure
There will be 5 smokers and 5 non-smokers participating in this investigation. The reason for choosing ten subjects because, more subjects will give more data to obtain an average, from which I can make a valid conclusion. I will need to repeat each person experiment at least twice for better results.
The stepping movement is in four stages:
- Step up
- Put both feet on the step
- Step down
- Put both feet on the floor
Each cycle begin and ends with both feet on the floor.
- Each subject will perform steps-up for 8 minutes
- The pulse rate of the subjects will be taken at rest for 30 seconds, pulse rate again has to be taken just after the exercise for 30 seconds and finally again during the recovery time for another seconds. The pulse rate then will be doubled to attain for one minute.
- The blood pressure of the subjects has to be taken at rest, straight after the exercise and finally after the exercise during the recovery time.
Safety
Before continuing with the experiment (exercise), the subjects will need to warm up to get their muscle up and running, so they don’t suffer from muscle fatigue after the exercise. To do this, they will need to go up and down of stairs without resting, at least three to four times. Take their pulse reading for 15 seconds, if it is over 40, or they feel pain in their chest, they shouldn’t carry on with the test, because it is not safe. This, have to be done to make sure that they are not at risk.
Fair Test
All participants in this investigation have to be between the age of 16-18 yrs and all ten of them are boys. This is necessary because, age, gender affects the fitness level of individuals, for example a female participant will have lower fitness level when compared to a male participant.
It is important that the fitness level of participant is assessed before hand. This will be done, by giving them to fill in a survey. For their weight, height and the type of diet that they have etc.
The height of the step must be the same (25cm) for all the experiments carried out.
Factors to control
- All the participants will be tested on empty stomach (before they have any food)
- The intensity of the exercise must remain the same through out the investigation, because I’m not measuring the effect of strenuous exercise
- The length of exercise must be the same for all participants
- Same step must be used by all the participant
After obtaining the data I will compare blood pressure and heart rate (pulse rate) of smokers and non-smokers.
Reference
A/S OCR Biology
Advanced Biology, Jones and Jones
National Cancer Institution