Upper Body Versus Lower Body Exercises - Term Paper Example

Abstract Medical practitioners have had an interest in understanding the physiological differences between lower body exercises and upper body exercises. Understanding the physiological responses of these two distinct types of exercise is of paramount importance in the formulation of prudent exercise programs to patients. This particular study involved subjects undergoing a maximal cycling test and a hand crank test on a Monark Ergomedic 834E. Subjects were administered with similar exercise intensities in the two exercises and physiological data such as maximal oxygen consumption, maximal carbon dioxide release, minute ventilation and respiration exchange ratio were recorded as the exercises progressed. It was observed that lower body exercise results in greater maximal oxygen consumption as compared to an upper body exercise. Maximal heart rate was also higher during the lower body exercise than during the upper body exercise. Peak blood lactate levels were higher during the lower body exercise as compared to during the arm exercise. The rate of perceived exertion was lower during the arm exercise than during the lower body exercise. The difference in physiological responses is as a result of the difference in energy requirements for the two exercises. Lower body exercises have more energy requirements compared to upper body exercises largely due to the greater muscle mass involved in lower body exercises. Introduction Upper body versus lower body exercises have been known to cause different physiological responses. Medical practitioners, therefore, have a great interest in understanding this physiological difference so as to be able to address different medical needs with their patients. Different patients will be directed to different forms of exercise according to the desired results. Different physiological aspects will be measured which include Maximal oxygen uptake- this is the maximum oxygen consumption that a human body can achieve during incremental exercise. The human body takes up oxygen for use in aerobic respiration in the process of oxidation. Haemoglobin has a maximum capacity of oxygen that it can absorb, the maximal oxygen uptake. Maximal carbon dioxide release- this is the maximum level of carbon dioxide concentration in the body. Carbon dioxide is a by-product of aerobic respiration. Heart rate- this is basically the number of heart beats per unit time. The heart rate varies so as to maintain a stable environment in the human body such as blood pressure regulation and removal of toxins from the body. Peak blood lactate concentration- this is the maximum concentration of lactic acid in the blood during incremental exercise. The concentration of blood lactate reflects the balance between lactate production and clearance. Lactate is produced in the body during anaerobic respiration as a by-product in the process of glycolysis. Rate of perceived exertion- This is a measure of physical exercise intensity level. The rate of perceived exertion varies with different types of exercises and also with the amount of load involved in an exercise. McArdle W.D., Katch, F.I. and Katch, V. L. in their book Essentials of Exercise Physiology found out that during an upper body exercise, there is a relatively smaller muscle mass that is involved, which accounts for the relatively lower heart rate and pulmonary ventilation. The cardiovascular center in the brain receives reduced stimulation which keeps the maximal heart rate lower compared to a lower body exercise. An upper body exercise results to a higher oxygen uptake compared to a lower body exercise. This results from the higher energy requirements that occur so as to support the torso during an arm-exercise. Lower body exercise also produces a lesser physiological strain (pulse rate, cardiac output and pulmonary ventilation) compared to upper body exercise. Bronas, U.G. in his book, Comparison of the Effect of Upper Body Ergometer Aerobic Training Vs. Treadmill Training on Walking Distance in Patients with Claudication. Influence of Central Cardiorespiratory Improvement. A Randomized Controlled Study, found out that in an upper body exercise, the human body achieves about 70% of the maximal oxygen uptake that the human body achieves during a lower body exercise. This is largely attributed to lower maximal pulse rate and lower stroke volume. During the upper body exercise, there occurs an increased systolic blood pressure caused by the vasoconstriction of the large arteries in the lower limbs and also due to the isometric contractions of the muscles of the arm which is working. The individual therefore experiences a higher total peripheral resistance during upper body exercise which results in a higher oxygen requirement during this exercise. The proportion of cardiac output going to the lower body is larger during an upper body exercise than during a lower body exercise. Non-exercising lower limb muscles do produce blood lactate at a higher rate during an upper body exercise as compared to during a lower body exercise while keeping the workload constant. The use of a smaller muscle mass during an upper body exercise as compared to a lower body exercise while keeping work intensity same, explains the higher minute ventilation during an upper body exercise. A research done by Bhattacharya and McGlothlin found out that the rate of perceived exertion is correlated to the amount of muscle mass involved in an exercise. Also correlated to the muscle mass include pulse rate and oxygen consumption. An upper body exercise achieves higher heart rates than those of a lower body exercise. Arm exercises were observed to have the highest rate of perceived exertion in relation to pulse rate. Ventilation was observed to have increased more relative to heart rate for the arm exercise compared to the lower body exercise (with a regression coefficient of 30 %). The aim of this study is to compare the difference in physiological responses of an upper body exercise and a lower body exercise. The paper therefore aims at showing the difference in various physiological differences that occur during an incremental exercise involving the lower body and the upper body and then making explanations for the different physiological differences. Methods Four well-trained men were selected for this experiment. The four subjects were all sports science students with their training status ranging from recreationally active to highly trained. They were invited to Edith Cowan University (ECU) to undergo a VO2 Max cycling and hand crank test. They were recruited through ECU and all the four freely agreed to take part in this study. ECU ethics committee permitted the tests. The four subjects were also confirmed fit and healthy with no serious medical conditions to stop them from participating in the experiment to completion. The study comprised two experiments, a max cycling test using a bicycle ergometer and a hand crank test using a Monark 818E, Sweden. Table 1. Subject demographics for 4 sports science students. PARTICIPANT AGE (Years) WEIGHT (Kgs) HEIGHT (Inches) NT 22 75.7 71.3 DP 25 88.75 74 BC 22 100.2 40.6 TG 28 88.15 74.8 MEAN 24.25 88.2 65.175 Before commencing the test, resting measurements of all 4 sport science students were taken. Firstly the Polar a3 heart rate monitor (Polar a3, Finland) was attached to the subject. A resting heart rate measurement was then recorded after an adequate rest period. As well as this, a resting blood lactate measurement and resting ventilation rate was recorded. These were completed by using the blood lactate analyser (accutrend lactate, Germany) and pneumotach (mouthpiece) which was connected to the metabolic cart (MedGraphics, USA) recording ventilation rates. In each of the two tests, each subject commenced cycling at 70 RPM at 35W and increased by 35W (0.5 kilopond) every 30 seconds. The subjects were mounted with an ergometer, attached with a nose clip and mouthpiece, and begun the exercise while the metabolic cart started to record relevant information. Subjects completed as many workloads until they could no longer ride and maintain the 70RPM required of them. Data was collected and recorded for each subject at the end of each bout of exercise such as heart rate (HR), average steady state VO2, VCO2 and RER. At the completion of the test, the nose clip and mouthpiece were removed and rinsed by the instructors and the mouthpiece was then placed in a saline solution. After every 30 seconds of exercise, continually add 35W (0.5KP) of power until the subject reaches volitional exhaustion. Verbal encouragement must be maintained throughout the test. Heart rate, blood lactate and rate of perceived exertion scale (RPE scale, Borg) were all recorded after every 1 minute. Also various ventilatory parameters will be recorded every 30 seconds via the metabolic cart (MedGraphics, USA) and pneumotach. These parameters include, minute ventilation (VE), respiratory exchange ratio (RER), maximal oxygen consumption (VO2) and maximal carbon dioxide consumption (VCO2). Once the subject has reached volitional exhaustion or ceased the test, the subject was instructed to begin to recovering via slowly cycling on the cycle ergometer (Monark 818E, Sweden) and POST 1 minute exercise, a final blood lactate sample will be obtained. Results Table 2: the table shows the maximal oxygen uptake for the for subjects for the two exercises (mean, variance and standard deviation included) PARTICIPANT VO2PEAK(mL.kg.min)_CYCLE VO2PEAK(mL.kg.min)_CRANK NT 48.50 27.20 DP 43.00 33.10 BC 31.60 25.00 TG 47.00 30.00 MEAN 42.53 28.83 VAR 58.44 12.31 SD 7.64 3.51 MIN 31.60 25.00 MAX 48.50 33.10 The maximal oxygen uptakes (VO2) for all the subjects during the maximal cycle test were higher than those of the hand crank test. The mean maximal oxygen uptake for the four subjects during the cycling test was 42.53 mL.kg/min (with SD = 7.64) while the mean VO2 for the four subjects during the hand crank test was 28.83 mL.kg/min ( with SD = 3.51). The maximum and minimum VO2 during the cycling test were 48.50 mL.kg/min and 31.60 mL.kg/min respectively. The maximum and minimum VO2 during the hand crank test were 33.10 mL.kg/min and 25.00 mL.kg/min respectively. Table 3: the table shows the maximal heart rates for the four subjects during the two exercises (mean, variance and standard deviation included) PARTICIPANT HR(beats.min)_MAX_CYCLE HR(beats.min)_MAX_CRANK NT 180.00 176.00 DP 183.00 171.00 BC 199.00 189.00 TG 181.00 155.00 MEAN 185.75 172.75 VAR 79.58 197.58 SD 8.92 14.06 MIN 180.00 155.00 MAX 199.00 189.00 The maximal heart rates during the cycling test were higher than those of the hand crank test for all the four subjects. The mean maximal heart rate during the cycling exercise was 185.75 beats/ min (with SD = 8.92 beats/min) while during the hand crank test, the mean maximal heart rate was 172.75 beats/min (with SD = 14.06 beats/min). The greatest and least maximal heart rates during the cycling exercise were 199 beats/min and 180 beats/min respectively. The greatest and least maximal heart rates during the hand crank test were 189 beats/min and 155 beats/min respectively. Table 4: the table below shows the blood lactate levels for the four subjects before the commencement of the two exercises and also the peak blood lactate levels during the two exercises (including means, variances and standard deviations) PARTICIPANT BLA_PRE_CYCLE BLA_PEAK_CYCLE BLA_PRE_CRANK BLA_PEAK_CRANK NT 2.20 13.30 1.80 8.20 DP 1.80 13.40 2.20 11.70 BC 1.70 14.90 1.60 9.10 TG 2.00 12.20 1.20 7.00 MEAN 1.93 13.45 1.70 9.00 VAR 0.05 1.23 0.17 3.98 SD 0.22 1.11 0.42 1.99 MIN 1.70 12.20 1.20 7.00 MAX 2.20 14.90 2.20 11.70 The mean blood lactate concentration in the pre-exercise period during the cycling exercise was 1.93 (with SD = 0.22) while during the hand crank test it was 1.70 (with SD = 0.42). The mean peak blood lactate concentration during the cycling exercise was 13.45 (with SD = 1.11) while during the hand crank test it was 9.00 (with SD = 1.99). The greatest and the least individual blood lactate levels during the cycling exercise were 14.90 and 12.20 respectively. The greatest and the least individual blood lactate levels during the hand crank exercise were 11.70 and 7.00 respectively. Table 5: the table below shows the rate of perceived exertion by the four subjects before the start of the exercises and also during the two exercises (including means, variances and standard deviations) PARTICIPANT RPE_PRE_CYCLE RPE_PRE_CRANK RPE_POST_CYCLE RPE_POST_CRANK NT 6.00 6.00 20.00 17.00 DP 6.00 6.00 20.00 19.00 BC 6.00 6.00 16.00 17.00 TG 6.00 6.00 20.00 16.00 MEAN 6.00 6.00 19.00 17.25 VAR 0.00 0.00 4.00 1.58 SD 0.00 0.00 2.00 1.26 MIN 6.00 6.00 16.00 16.00 MAX 6.00 6.00 20.00 19.00 The RPE was 6.00 for all the four subjects before the start of the two exercises. The cycling exercise had a mean RPE of 19.00 (with SD=2) while the hand crank test had a mean RPE of 17.25 (with SD= 1.26). The cycling exercise had a maximum individual RPE of 20 and a minimum of 16. The maximum individual RPE during the hand crank exercise was 19 while the minimum was 16. Discussion The physiological changes that occur within the human body during a sub maximal exercise depend on various factors, which include the intensity and frequency of the exercise and also the environmental conditions under which the individual is exercising in (Jurimae et al, 2010). The extent to which these physiological changes occur depends on the type of exercise being taken, such as, whether it is an upper body exercise or a lower body exercise. During exercise, there occurs various cardiovascular, respiratory and ventilatory changes that are aimed at coping up with the increased oxygen and substrate requirements in the skeletal muscles. These changes also occur so as to meet the increased demand of metabolites and carbon dioxide removal from the skeletal muscle. An upper body exercise and a lower body exercise have different energy requirements, and hence different extents of these physiological changes (Jurimae et al, 2010). Before the start of the exercise (at the rest position), the human body is normally functioning at the basal metabolic rate, a metabolism rate just enough to support life. The energy requirements by the body are provided by adenosine triphosphate (ATP) and phosphocreatine. These two chemicals are mainly responsible for the supply of energy to the skeletal muscle before the human body can initiate any other extra metabolic processes. Therefore, the energy requirements before the start of a lower body exercise or an upper body exercise are relatively equal. As the intensity of the exercise increases, the human body has to adopt to extra energy requirements by the muscles. Various metabolic, cardiovascular and ventilatory changes occur as a result of this. Once the exercise is initiated, the body experiences an increased breathing rate meant to increase the rate of oxygen uptake by the body cells. This increased oxygen uptake leads to an increased aerobic respiration rate and metabolism which supplies the extra energy needed during exercise (Eldridge, 1985). The rampant increase in minute ventilation on the onset of the exercise is as a result of signals sent to the respiratory control centre in the brain from the mechanoreceptors in the skeletal muscle ( Baar, 2002). At sub maximal exercise intensities, ventilation increases linearly with increase in work rate. Tidal volume and respiratory rate are responsible for the increase in pulmonary ventilation. As exercise continues, there occurs an increased level of carbon dioxide in the blood as a result of the increased breakdown of glucose into energy, water and carbon dioxide. The increase in oxygen uptake by the cells and carbon dioxide concentrations in the blood causes the heart rate and blood pressure to increase (Marshall & Desai, 2010) . This so happens to facilitate faster delivery of oxygen from the lungs to the tissues and carbon dioxide from the tissues to the lungs (Baar, 2002). The rate of oxygen uptake increases up to a certain point after which it does not increase any further, the maximal oxygen uptake ( Grimby & Saltin,1966 ). This is so because hemoglobin can only absorb and transport a certain maximum amount of oxygen at any given time ( Shephered, 1964). A lower body exercise results to a higher maximal oxygen uptake than that of an upper body exercise. This is largely attributed to the higher maximal pulse rate and higher stroke volume. A lower body exercise leads to a maximal oxygen uptake that is about 40 % higher than the one that would be achieved during an upper body exercise (Marshall & Desai, 2010). But the body still needs more energy to support the exercise energy requirements, so after the body attains the maximal oxygen uptake, it switches to anaerobic respiration. Anaerobic respiration is a form of cellular respiration that involves the use of an external electron acceptor other than oxygen to break down glucose into energy, lactic acid and ATP (Mead & Agostini, 1964). The accumulation of lactic acid during the anaerobic phase of respiration is responsible for the recorded increase in blood lactate concentration. A lower body exercise leads to a higher peak blood lactate levels that an upper body exercise during an incremental exercise. This is because during a lower body exercise, larger muscle groups are involved (which include quadriceps, hamstrings, hip adductors, gastrocnemius) as compared to the lesser muscle groups involved in an arm exercise (which include biceps and triceps) ( Faria & Faria, 1998). The larger muscle groups consume more energy even in the anaerobic phase of the incremental exercise which means that they will also produce more lactate during anaerobic respiration. The accumulation of lactate in the lower body muscles will need to be cleared, which triggers the heart rate to increase so as to pump blood at a higher pressure towards these body regions ( Faria & Faria, 1998). A lower body exercise also has a higher rate of perceived exertion attributable to the larger muscle mass involved as compared to an upper body exercise. Lower body exercises therefore have higher energy requirements compared to upper body exercises, which explains the difference in the magnitude of the physiological responses. References Shepherd, R.H.(1964). Effects Of Pulmonary Diffusing capacity on exercise tolerance. J.Appl. Physiol.19, 284-286. Mead, J., Agostoni, E. (1964). Dynamics of breathing. In Handbook of Physiology, vol 1 (3), 411-427. Grimby, G., Saltin, B. (1966). Physiological Analysis of Well Trained middle-aged and old athletes. Acta. Med. Scand., 179, 513-526. Baar, K. et al. (December 2002). Adaptations of skeletal muscle to exercise: rapid increase in the transcriptional coactivator PGC-1, 16 (14), 1879-1886. Eldridge, F.L., et al. (March 1985). Stimulation by central command of locomotion, respiration and circulation during exercise, 59 (3), 313-337. Bhattacharya, A., McGlothlin, J.D. (2012). Occupational Ergonomics: Theory and Applications, Second Edition. Boca Raton: CRC Press. McArdle, W.D. et al. (2006). Essentials of Exercise Physiology. New York: Lippincott Williams & Wilkins. Faria, E.W., Faria, I.E. (May 1998). Cardiorespiratory responses to exercises of equal relative intensity distributed between the upper and lower body. Journal of Sports Sciences, 16 (4), 309-315. Marshall, P.W., Desai, I. (June 2010). Electromyographic analysis of upper body, lower body, and abdominal muscles during advanced Swiss ball exercises. J Strength Cond Res , 24 (6), 1537-1545. Jurimae, T. et al. (July 2010). Relationship between rowing ergometer performance and physiological responses to upper and lower body exercises in rowers. J Sci Med Sport, 13 (4), 434-437. Read More