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Direct measurement of Aerobic Power (VO2max)
Subjects details:
Sex: male
Age: 20 years old
Height: 180 cm
Weight: 78 kg
Subject described his level of activity as active (consent form).
Resting BP: 154/78
Resting HR: 72bpm
Pre-testing blood lactate: 1mmol/l
Testing protocol:
#You can find VO2 max test protocol visiting the link at the end of the page#
Warm-up phase: Stretching exercises and moderate jogging for 5 min period.
#At this point you must add the test protocol#
#Then add Tabular representation of the VO2 max test results (VO2 ml/min, VCO2 ml/min, RER, VO2 (ml.kg.min-1), and VE l/min against time)#
#Then add Graphical representation for the obtained VO2 values#
Evaluation whether the subject reached true VO2 max level with respect to the BASES criteria:
Identification whether the subject reached his true VO2 max level based on the five BASES criteria:
i) A plateau in the oxygen uptake/exercise intensity relationship. This has been defined as an increased in oxygen uptake of less than 2 ml.kg-1.min-1.
ii) A final respiratory exchange ratio of 1.15 or above.
iii) A final heart rate within 10 b.min-1 of the age-related maximum.
iv) Post exercise (5min) [Bla] of 8mmol.l-1 or more.
v) Subjective fatigue and volitional exhaustion.
During the last stages of the test, the oxygen uptake was less than 2 ml.kg-1.min-1. Additionally, final respiration exchange ratio was above 1.15. Subjects final RER value was at 1.23. Moreover, Final heart rate (HR) was within 10 b.min-1 of the age-related maximum. 220-subjects age = 200. Subjects final HR was at 198bpm, HR which lying within the desirable values. Furthermore, post exercise [Bla] was at 11.1mmo-1. Testing procedure was stopped after the end of the 16th min since subject felt physiological fatigue (RPE 20). Based on the tests result subject reached true VO2 max level. Despite the 5 BASES criteria, there is an additional indicator in order to determine true VO2 max value. No further increase in VO2 during the last stage of the test is needed in order to establish true VO2 max level. However, based on the table 1 there was no decline of VO2 during the last stage of the test.
Ethical issues concerned with maximal aerobic testing.
Maximal aerobic tests are usually last more than thirteen minutes but less than eight minutes. During the last stages of the tests, subjects required to perform exercise at their peak physiological values. That includes, peak cardiorespiratory and cardiopulmonary work output. Moreover, throughout the duration of the maximal aerobic performance, the test is getting harder since there is a continuously elevation of the percentage of blood lactate in the blood. The beginning of the test might be painless for the subject. However, the final stages of the test should gradually lead the subject to physiological exhaustion. Maximal aerobic testing involves a high degree of physical risk and discomfort and it is important that subjects should be aware of these factors. Additionally, subject should not be under any compulsion to participate and should be free to withdraw from the test at any stage without consequences. Before every experimental or testing procedure, sport scientists must provide their subject with a pre-test questionnaire (appendix 1). Moreover, for safety reasons, the testing procedures should be always carried out with a physician being readily available and aware of the procedures being used.
Indirect measurement of Aerobic Power (VO2 max) using cycle ergometer.
Average HR during the 5th and 6th min = 142 bpm
Work rate = 1,180 kgr/min
Based on the Astrand-Rhyming nomogram VO2 max = 4.2 L/min
#You can find the Astrand-Rhyming nomogram in exercise physiology books#
Compare and contrast of the direct and indirect methods used to measure aerobic power in term of validity and reliability, and comments on the endurance potential of the subject.
In sports fitness testing it is very important that the applying tests are both reliable and valid. Test reliability refers to consistency of measurement, the extent to which a test yields the same results for the same individual over time. Validity is whether the tests actually measure what they set out to. Tests can be reliable but not valid. The validity of a test is usually better if the test is specific to the sport being tested. In the specific case, both techniques were used to measure the subjects maximum aerobic power. Treadmill ergometer was used for the direct measure of aerobic power and cycle ergometer was used for the indirect prediction of aerobic power. Subjects major sport activity was football. Apart from the level of his technical characteristics, subjects performance is based on running ability. Running activity was more relative to his sport; therefore, in order to maximize the validity of the test, the subject must perform the test on a treadmill ergometer. Treadmill ergometer was used for the direct measure of aerobic power. As a result, for the specific subject, direct method to measure aerobic power was more valid than the indirect method.
Both techniques were used to predict maximum aerobic power. The results from each method (direct, indirect) might be similar but the parameters, which were based on; in order to predict VO2 max values were differ. According to the direct method, the prediction of true VO2 max was based on the five BASES criteria. Conversely, according to the indirect method, the prediction of true VO2 max was based on HR, since the HR/ VO2 relationship is generally linear throughout progressive exercise (HR and O2 consumption-linear relationship to power between 50-90% HR max). Sports scientists main objective is to obtain the same similar results on two separate trials and this is important as they are often looking for small changes in scores. These small changes in scores are getting gradually more important as the level of athletic performance is getting higher. For that reason, sports scientists must recognize and identify when the changes in scores are due to improvement/worsening of athletic performance and when are due to test reliability. Direct measurement of aerobic power was more reliable since the estimation of the true VO2 max value was based on the 5 BASES criteria. On the other hand, indirect method was less reliable since the prediction of the true VO2 max value was based only on one physiological parameter. Which was the HR. To sum up, since the tests were performed on a well-trained footballer, direct method was more valid and reliable than the indirect method.
Based on the majority textbook data, a normal, healthy young adults VO2 max values ranging from a low of about 30 ml.kg.min-1 for an untrained person, up to 95 ml.kg.min-1 or more for a high well trained person. The reasons for this very wide range in values includes gender, body composition, muscle mass, level of maturity, inheritance and state of training. For a 20 years old male, the average VO2 max values are about 36 ml.kg.min-1 to 44 ml.kg.min-1. VO2 max value for the subject, who performed the test, was 55.6 ml.kg.min-1. His aerobic power was above the average values, indicating that the subject was fit. However, his maximum aerobic power was not high enough to indicate that the subject was high well-trained person.
SINGLE & MULTIPLE WINGATE TESTS
#You can find single and multiple Wingate test protocol visiting the link at the end of the page#
#At this point you must add the test protocol, and then the test's results both tabulaler and graphical#
Discussion of the results
The Wingate anaerobic test was developed at the Wingate institute in Israel in the 1970s. Since then, the Wingate test has been used more than any other test to assess anaerobic performance. Originally designed as a leg performance test, however it has also been adapted to test the anaerobic performance of the arms. The laboratory measurements of anaerobic power and capacity is more relevant to the athletes who required maximum power output over a sort period of time ranging from approximately a few seconds to few min. Based on the existing experimental procedures there are two types of Wingate testing; the single Wingate test and the multiple Wingate test.
Single Wingate test is more suitable for athletes that are required to perform just one supramaximal effort. For example, speed runners and speed cyclists. A single Wingate test performed on a modified Monark ergometer. The saddle adjusted so that the subjects leg is nearly straight with the ball of the foot on the down pedal. The subject asked to pedal as fast as possible for 30 secs. The resistance load was set at 6 kg. During the test, subject received vocal encouragement to ensure a supramaximal effort. At the end of the test, variables such as peak power, average (mean) power and fatigue index, are assessed. Peak Power (PP) defined as the highest mechanical power output. It is usually obtained within the first 5 secs of the test. It represents the explosive characteristics of the athletes muscle power. Mean Power (MP) represents the average local muscle endurance throughout the test. The subjects higher peak power was 884 W and it was achieved at 2.6 sec. Additionally, average power value was at 576 W. Peak and average power values during Wingate testing are related with the athletes ability to achieve a high rate of ATP production through the ATP-PC system and anaerobic glycolysis. Fatigue index (19.42W/s), defined as the difference between higher power output and the lowest 5-s power output divided by peak power. Additionally, testing output includes values for the subjects total work (17.29Kj) and min power (353W). Min power output is usually occurs at the end of the test (29.9secs).
On the other hand, multiple Wingate test is more suitable for athletes who participate in multiple sprint sports. For example, football players and basketball players. The multiple Wingate test performed on a modified Monark ergometer. The saddle again adjusted so that the subjects leg is nearly straight with the ball of the foot on the down pedal. The test involved periods of maximal work interspersed with recovery periods. At the end of the test, variables such as peak power, average (mean) power and fatigue index, are assessed. The subjects higher peak power was 904 W and it was achieved during the first stage of the test at 4.3 sec. Additionally, during the first stage, the subject achieved average power (774W), minimum power (904W) and total work (0.48J/kg). The aim of the experiment is to exam the athletes anaerobic power to sustain the values that he/she obtained at the first stage of the test throughout the multiple experimental stages. During the multiple testing stages there was a decline on the Av power, Max power, Min power and total work values. Greater variation on the values between the first and the last stage of the test, represent low anaerobic power. Conversely, minor variation on the obtained values between the first and the last stage of test represent high anaerobic power. Fatigue index value is an additional indicator for high or low anaerobic power. Huge increase of the fatigue index values represents low anaerobic power and vice versa. At the first stage of the test the subjects fatigue index value was 0.0W/s, at the second stage was 18.18W/sec and at the final stage it was almost doubled (35.57W/s) indicating great physical exhaustion. Accurate and valid execution of the multiple Wingate is very difficult. For that reason extensive experiences and closely coordination between the experimenter and the participants is needed.
To sum up, assessment of anaerobic performance through Wingate testing can provide the coach with valuable information about the athlete's fitness status as well as allowing them to monitor progress throughout the training sessions. The tests scores can reliable determine peak anaerobic power, anaerobic fatigue, and total anaerobic capacity. However, there are some parameters, which need further scientific investigation. For example, since power is the product of Torque (in Nm) and velocity, scoring in the Wingate test depends on the braking torque (in Nm) selected for each test. If the torque is low, the subject can pedal fast. If the torque is higher, the pedaling rate becomes slower. For every subject there is an optimal braking torque that yields the highest possible power, therefore further investigation is needed in order to obtain more accurate braking torque, based on the athletes types and needs.
FIELD TEST
1-mile walk test
Field tests are an alternative method to evaluate cardiorespiratory fitness. One-mile walk test is a different method to estimate aerobic power. According to the tests protocol, subject is required to walk as fast as possible for one mile on a flat measured track, and Heart Rate is measured at the end of the last lap. The following equation was used to estimate VO2 max (ml. Kg-1.min-1):
VO2 max = 132.853 0.0769 (wt) 0.3877 (age) + 6.315 (sex) 3.2649 (time) 0.1565 (HR)
Where (wt) is body weight in pounds, (age) is in yeas, (sex) equals 0 for female and 1 for male, (time) is in minutes and hundredths of minutes, and (HR) is in beats per minute.
Test validity is the extent to which a test measures what it purports to measure. The validity of a test is usually better if the test is specific to the activity being tested. Knowing that the subjects main exercise activity was daily walking, walk test will increase the validity of the tests results. Additionally field test will be closer to the environmental conditions that the subject is daily walk. However, the validity of the equation is limited since it was used to predict VO2 max on one population of men and women, aged 30-39, and was then validated on another comparable population. Nevertheless, despite the complexity of the experimental equation, this test appears to fill a void in field tests available to estimate maximal aerobic power since it uses a common activity (walking) and requires the simple measurement of heart rate.
Subjects details:
Gender: Female
Age: 38
RHR: 60 bpm
Weight: 70kgr (187.54 pounds)
Results:
Time: 15min
HR: 123 bpm
Based on the equation: VO2 max = 132.853 0.0769 (187.54) 0.3877 (38) + 6.315 (0) 3.2649 (15) 0.1565 (123)
VO2 max = 35.5 ml. Kg-1.min-1
Advantages and disadvantages of field-testing
To start with, field-testing is an additional scientific method to assess present and future athletic performance. Such tests are no less scientific than, and may by just as strongly controlled as, the more traditional laboratory tests. Similar to laboratory tests, field tests have advantages and disadvantages.
Advantages:
i) Athletes or general participants are closer to the real competitive or training conditions
ii) Reduction of the participants stress, since they perform the test in a familiar environment (e.g. track)
iii) Results more valid because of their specificity.
iv) Simple experimental protocols
v) Easy to conducted
Disadvantages:
i) Control of environmental conditions (e.g. humidity, temperature)
ii) Data collection systems are not accurate as those used in field tests
iii) Greater variation of the athlete performance
iv) Results less reliable
Despite the advantages and disadvantages of field tests, the results gained from a field-testing should be considered equally to those obtained from a laboratory test. However, the complexity of some sports makes the field-testing the only way to assess athletic performance. For that reason, field-testing is the only solution for sports that scientist is unable to effectively simulate in a laboratory settings.
References
Adams, G. M., 1998. Exercise physiology Laboratory manual. 3rd ed. Boston, USA: WCB McGraw-Hill.
BASES., Physiological testing guidelines. 3rd ed. Leeds: BASES.
Hopkins, W.G., et al (1999). Design and analysis of research on sport performance enhancement. Medicine and science in sport and exercise, 31 (3), pp. 472-485.
Kline, G.M., et al (1987). Estimation of VO2 max from one-mile track walk, gender, age, and body weight. Medicine and science in sport and exercise, 19 (3) pp. 253-259.
MacDougall, J. D., Wenger, H. A. & Green, H. J., 1991. Physiological testing of the high-performance athlete. 2nd ed. Champaign, 1II. Human kinetics.
Vandewall, H., et al (1987) standard anaerobic exercise tests. Sport medicine, 4 pp. 268-289
Yule, E., Kaminisky, L. A., Sedlock, D. A., King, B. A., & Whaley, M. H. (1996). Inter-laboratory reliability of VO2max and submaximal measurements. Medicine and Science in Exercise and Sports, 28(5), Supplement abstract 87.
University of Portsmouth, Department of sport and exercise science [no date]. Available online from: http://www.sci.port.ac.uk/~sportwww/index.html [accessed: 10,13,14 December 2001]
Sport coach home page [no date]. Available online from: http://www.brianmac.demon.co.uk/ [assessed: 12,13,15 December 2001] 
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