Results

Cardiovascular, respiratory, energy and muscular systems work in integrated manner during the short-term exercise. During exercise, muscles start to work. It requires more amount of oxygen. Hence, respiratory system retort promptly, and get more oxygen into the lungs. It results in augmented breathing rate and tidal volume. It also results in the more oxygenated blood carrying by the heart. Heart starts to pump at the faster rate. It results in increase in the heart rate. It also results in the augmentation in stroke volume, cardiac output and blood pressure. During exercise, there is increase in the activation of musculoskeletal system. Both cardiovascular system and respiratory system support sustained movement during duration of exercise. Both these systems undergo physiological adaptations, which are helpful in improving efficiency and capacity of body. Both cardiovascular and respiratory system, responds to low rate of work. However, it is difficult for both these systems to respond to higher rate of work. Increase in the oxygen demand results in the increase in cardiac output; however, this increase in cardiac output becomes stagnant when it reaches its maximal capacity (Plowman & Smith, 2013; Ehrman et al., 2013).

Increase in the rate of work results in the increase in the skeletal muscle oxygen demand and oxygen uptake (VO₂). Increase in the oxygen demand during exercise results in all the cardiovascular parameters because all these cardiovascular parameters are interrelated. Cardiac output is the total volume of blood pumped by the left ventricle per minute. Cardiac output is the product of heart rate and stroke volume. Stroke volume is the volume of blood pumped per beat. Arterial-mixed venous oxygen is the difference between amount of oxygen in arterial and mixed venous blood. Individual’s maximum oxygen uptake is function of cardiac output and arterial-mixed venous oxygen difference. During exercise, cardiac output and heart rate increase to the full extent; however, there is approximately 50 % increase in maximal oxygen uptake. During exercise, there is increase in only systolic blood pressure; however, there is no increase in the diastolic blood pressure. Peak value of blood pressure reaches upto 200 to 240 mmHg (Plowman & Smith, 2013; Ehrman et al., 2013).

Pulse pressure is the difference between the systolic and diastolic blood pressure. During exercise, there is increase in pulse pressure due to increase in systolic blood pressure. In resting condition, resting pulse pressure is approximately 30 – 40 mmHg and during exercise it reaches upto 100 mmHg. There is immediate increase in the pulmonary ventilation during exercise and it is mediated through potentiation of respiratory centres in the brain through motor cortex and feedback from the muscles and joints proprioceptors in the moving extremities. In short duration exercise, pulmonary ventilation mostly increases due to augmentation in the tidal volume. There is increase in the ventilation from 10 litres per minute to 100 litres per minute during short duration exercise (Kinnear & Blakey, 2014).

Aim of this study is to assess effect of short-term exercise on the physiology of cardiovascular and respiratory system.

Discussion

Objectives of this study is to assess effect of short-term exercise on heart rate, respiratory rate, blood pressure, gas composition and gas volume.

It has been hypothesized that there is increase in the physiological parameters of cardiovascular and respiratory system during short-term exercise.

In case of heart rate, data of the participants those are having heart rate outside 60 to 100 beats per minute need to be excluded. Some of the participants exhibited heart rate less than 60 and more than 100. Data for such participants need to be excluded because normal heart rate is between 60 to 100 beats per minute. In case of respiratory rate, data of the participants those are having respiratory rate outside 12 to 20 breaths per minute need to be excluded. Some of the participants exhibited respiratory rate less than 12 and more than 20. Data for such participants need to be excluded because normal respiratory rate is between 12 to 20 breaths per minute. In case of blood pressure, data of the participants those are having systolic blood pressure outside 120 to 140 mmHg need to be excluded. Some of the participants exhibited systolic blood pressure less than 120 and more than 140. Data for such participants need to be excluded because normal systolic blood pressure is between 120 to 140 mmHg.

In figure 1, respiratory rate data is presented. Per minute data is given for respiratory rate. Data is given for the entire 15-minute duration of the exercise experiment. It helps in assessing, effect of exercise on change in breath rate for every minute. For the resting period, obtained data remain constant for the entire duration of 5 minutes in the range of 19.912 to 21.316 breath per minute with 20.895, 19.912, 20.0, 21.316 and 21.316 breath per minute at 1, 2, 3, 4 and 5 minutes respectively. During exercise, data is given for the duration of 6 to 10 minutes. It is evident that breath rate increased gradually from 6 minute to 10 minutes, except for 8 minute. During exercise, obtained breath rate is 27.053, 30.719, 30.298, 31.518 and 31.911 at 6, 7, 8, 9 and 10 minutes respectively.  Post exercise, obtained breath rate is 25.786, 24.429, 23.429, 22.107 and 23.0 at 11, 12, 13, 14 and 15 minutes respectively. It is evident, there is gradual decrease in the respiratory rate. 

Pulse pressure in mmHg is calculated by subtracting diastolic blood pressure from systolic blood pressure. Pulse pressure was calculated in resting condition, during exercise and post exercise. Calculated pulse pressure is 38.523, 48.063 and 41.738 mmHg at resting, during exercise and post exercise respectively.   

Expired CO₂ (FeCO₂, as a %) was measured at rest and during exercise. Obtained FeCO₂ is 2.4156 and 3.399 at rest and during exercise respectively.  

Data for the respiratory rate, pulse pressure and expired CO₂ are presented in the form of chart graphs. This type data presentation is simple to understand. Graphical representation of the data present data in the form of visuals and not in the form words or numbers. Graphical data gives the substance of the obtained data rather than technical details behind the data. Graphical representation helps in memorizing effect about the obtained data. In this study, graphical representation of data is more relevant because it facilitates comparison of data between different time periods.

Obtained results indicated that there is increase in the physiological parameters of cardiovascular and respiratory systems during exercise. It indicates that obtained results met hypothesis which was formed at the beginning of the study. Obtained results indicate that there is gradual increase in the heart rate and respiratory rate with increase in the time and duration of the exercise. During this 5-minute exercise, there is no saturation in the obtained values of heart rate and respiratory rate. It indicates, both these physiological parameters don’t reach to its peak level. After the completion of exercise, there is gradual decrease in heart rate and respiratory rate. Earlier studies reported that there is increase in total blood pressure during exercise; however, diastolic blood pressure remains same during exercise (Durrani & Fatima, 2015; Carpio-Rivera et al., 2016). Results obtained in this study also indicated that there is increase in the systolic blood pressure; however diastolic blood pressure remains at the normal level. Blood gas composition changes during exercise with increase in the concentration CO₂ and decrease in the concentration of O₂. O₂ concentration decrease due to increased consumption to fulfil increased demand (Gill et al., 2014).

Central and peripheral chemo receptors are sensitive low levels of O₂ (hypoxia) and high levels of CO₂ (hypercapnia). From the current study and previous studies, it is evident that exercise results in increase in CO₂ levels and decrease in O₂ levels (Roman et al., 2016; Coffman et al., 2017). Air usually transfers from area of high pressure to lower pressure. During breathing, contraction and flattening of the diaphragm and the contraction of the external intercostal muscles results in inspiration. During expiration, inspiratory muscles relax which results in the elastic recoil of lungs. It produces pressure equilibrium prior to start of the next cycle. During ventilation, gaseous exchange occurs at alveoli. Due to more consumption of oxygen, partial pressure of O2 in the atmosphere is more in comparison to the bloodstream and partial pressure of CO2 in the bloodstream increases in comparison to atmosphere. As a result of lowered O2 levels, lungs try to compensate deficient O2 levels by breathing faster. Hence, there is increase in the breathing rate during exercise (Kinnear & Blakey, 2014; Ehrman et al., 2013).  

Oxygen-transport system comprising of heart, lungs, arteries and veins, is highly stressed in the long duration exercise like bike exercise. However, efficiency is more in bike exercise. Higher efficiency indicates that consumption of oxygen is at lower rate in comparison to other exercise. Human body comprising of two types muscle fibres like aerobic and anaerobic muscle fibres. There is difference in the consumption of O2 between the aerobic and anaerobic muscle fibres. Aerobic muscle fibres consume oxygen directly from the blood to produce mechanical energy. Anaerobic muscle fibres can operate without sufficient supply of oxygen. Resting muscles are with low blood supply and without sufficient oxygen supply (Patel et al., 2017). In bike exercise, pedal force needs to be increased for the longer duration without using anaerobic fibres. It is evident that there is increase in the maximum heart rate and respiratory rate during bike exercise due to use of aerobic muscle fibres. Since, oxygen consumption is with slower rate during bike exercise, even though maximum increase in the heart rate and respiratory rate do not produce exhaustion in the individual. In comparison to the walking and running, bike exercise requires more muscle force and muscle speed. Moreover, bike exercise requires more leg muscle extension and contraction as compared to running or walking (Porcari et al., 2015).  

Cardiovascular and respiratory physiology alters due to multiple factors. Age and metabolic disorders are also responsible for the alteration in the cardiovascular and respiratory physiology. Hence, experiment should have designed in such way that there could be separate collection of data for participants with varied age groups. From the collected data, it difficult to gather information related to effect of metabolic disorders on the cardio-pulmonary physiology during exercise. In participants with metabolic disorder, it is difficult to assess, whether changes in cardio-pulmonary parameters are due to exercise or metabolic disorder (Fresiello et al., 2016). In this experiment, additional parameters like body temperature and electrolyte levels could have evaluated because changes in these parameters alters cardio-pulmonary physiology.

Resource requirements for this study depends on the objective of the experiment and resources available for experiment. Objectives of the experiment should not be decided, if relevant resources are not available. Reference data relevant to the respective resources instrument need to be collected. Reference data is helpful in validating use of resource instrument. It is essential to use validated instrument to obtain robust data. Moreover, there should be availability of experienced and skilled persons to operate selected resource instruments. Blood pressure and heart rate measurement instruments require skilled person to operate it; otherwise, there is possibility of inaccurate measurement of blood pressure and heart rate. References in this report need to included from the peer reviewed journals with good impact factors. References need to be included from the published research conducted at the recognised organisations and institutes.

I learned that, in a group setting every member of the group should be aware of all the aspects of the experiment. However, different tasks of the experiment need to be carried by specific person. Relevant competency needs to be identified to assign specific task to the relevant person. There should be effective communication and coordination among all the members of the team. Someone with good experience need to take leadership role during conducting experiment in the group setting. 

References:

Carpio-Rivera, E., Moncada-Jiménez, J., Salazar-Rojas, W., & Solera-Herrera, A. (2016). Acute Effects of Exercise on Blood Pressure: A Meta-Analytic Investigation. Arquivos Brasileiros de Cardiologia, 106(5), pp. 422–433.

Coffman, K.E., Carlson, A.R., Miller, A.D., Johnson, B.D., & Taylor, B.J. (2017). The effect of aging and cardiorespiratory fitness on the lung diffusing capacity response to exercise in healthy humans. Journal of Applied Physiology, 122(6), pp. 1425-1434.

Durrani, A. M., & Fatima, W. (2015). Effect of Physical Activity on Blood Pressure Distribution among School Children. Advances in Public Health, 379314, pp. 1-4. https://doi.org/10.1155/2015/379314.

Ehrman, J. K., Gordon, P. M., Visich, P. S., & Keteyian, S. J. (2013). Clinical Exercise Physiology. Human Kinetics.

Fresiello, L., Meyns, B., Di Molfetta, A., & Ferrari G. (2016). A Model of the Cardiorespiratory Response to Aerobic Exercise in Healthy and Heart Failure Conditions. Frontiers in Physiology, 7(189), doi: 10.3389/fphys.2016.00189.

Gill, M., Natoli, M.J., Vacchiano, C., MacLeod, D.B., Ikeda, K., et al. (2014). Effects of elevated oxygen and carbon dioxide partial pressures on respiratory function and cognitive performance. Journal of Applied Physiology, 117(4), pp. 406-12.

Kinnear, W., & Blakey, J. (2014). A Practical Guide to the Interpretation of Cardio-Pulmonary Exercise Tests. OUP Oxford.

Patel, H., Alkhawam, H., Madanieh, R., Shah, N., Kosmas, C.E., & Vittorio, T.J. (2017). Aerobic vs anaerobic exercise training effects on the cardiovascular system. World Journal of Cardiology, 9(2), pp. 134-138.

Plowman, S. A., & Smith, D. L. (2013). Exercise Physiology for Health Fitness and Performance. Lippincott Williams & Wilkins.

Porcari, J., Bryant, C., & Comana, F. (2015). Exercise Physiology. F.A. Davis.

Roman, M.A., Rossiter, H.B., & Casaburi, R. (2016). Exercise, ageing and the lung. European Respiratory Journal, 48(5), pp. 1471-1486.