Aerobic capacity test - Essay Example

Aerobic Capa Test Aerobic capa is an essential part of physical fitness because it reflects the overall capa of the cardiovascular and respiratory systems (Mitchell, Sproule, & Chapman, 1958; Taylor, Buskirk, & Henschel, 1955) and the ability to carry out extended demanding exercise (Astrand & Rodahl, 1986; Taylor et al, 1955). Aerobic capacity (VO2max) reflects the maximum rate that oxygen can be taken up and utilised by the body during exercise (Cureton and Plowman, n.d.). Maximal oxygen uptake is defined as the region in which oxygen consumption increases only a little with more increases in the intensity of the exercise. Maximal oxygen uptake is also known as maximal oxygen consumption, maximal aerobic power, aerobic capacity, or VO2 max. The maximal oxygen uptake (VO2 max) is a measure of a person's capacity to take in and utilise oxygen during exercise. A subject with a greater VO2 max value will be more likely to sustain high intensity exercise for a longer period. Theoretically, subjects with greater VO2 max values possess greater concentrations of hemoglobin in the blood, thus enabling them to utilise more oxygen during intense exercise (McArdle, Katch, & Katch, 2001; Mierke, 2003). However, there are several factors that may have an affect on maximal oxygen consumption (VO2 max). These factors include mode of exercise (i.e., treadmill exercise, cycle ergometry, arm crank, swimming, or bench stepping), heredity, gender, age, body size and composition, and state of training (McArdle, Katch, & Katch, 2001; Mierke, 2003). Measuring aerobic capacity in the laboratory Aerobic capacity is measured in the laboratory using a graded exercise test during which the rate of oxygen uptake is measured continually using sophisticated equipment. A graded exercise test is a test typically administered on a treadmill or cycle ergometer in which the intensity of exercise is increasingly increased. The rate of aerobic metabolism and oxygen uptake increases as intensity of exercise increases up to the point at which the aerobic capacity is reached. At this point, even though the exercise intensity can be increased, the oxygen uptake no longer increases proportionally, and there is a plateau in the relation of the rate of oxygen uptake to work rate (exercise intensity).The rate of oxygen uptake at the plateau is aerobic capacity (Cureton and Plowman, n.d.). The main disadvantage of this type of test is that is technically demanding, requiring costly equipment and highly-trained technicians.Furthermore, it is time consuming; a test requires about 30 minutes and only one subject can be tested at any given time. Thus, the direct measurement of aerobic capacity is not possible or practical for most field settings, such as schools where large numbers of people must be tested (Cureton and Plowman, n.d.). The Bruce Treadmill Test is one of the most popular laboratory treadmill test protocols used in obtaining VO2 max measurements. The test consists of seven 3-minute stages, in which most subjects are able to walk the first three stages. During each stage, a set percent treadmill grade and speed is obtained. During the test, the subjects' breathing and heart rates are monitored through the use of respiratory and metabolic/gas equipment along with heart rate monitors. Subjects' heart rates are recorded every minute while the rate of perceived exertion (RPE) is recorded every three minutes. Validity correlation coefficients of .90 and .91 have been reported between VO2 max and the 12 min run. A lower correlation has been reported between VO2 max and the 1.5 Mile Run (-.74). The test-retest reliability of maximal oxygen consumption tests is high (i.e., .95 - .99) (Mierke, 2003). The main advantage of this test is that it is a direct measurement of maximal oxygen consumption. However, there are quite a few disadvantages with this test including degree of difficulty, cost and sensitivity of equipment, and the need for highly-trained technician to manage the test. One advantage of this test is that this test is the most widely used and accurate measure of aerobic fitness. One disadvantage of this is the occasional malfunction of equipment. Without the respiratory/ventilation readings, subjects are forced to use an indirect indicator of maximal oxygen consumption (Adams, 2002; Mierke, 2003). The Astrand Rhyming Test predicts maximal oxygen consumption (VO2 max) based upon the steady-state heart rate of a person exercising at a submaximal power level for 6 minutes. The subject pedals a cycle ergometer at a specific cadence (50 rpm) against a prescribed resistance setting. This setting may be adjusted during the test to elicit a certain range of heartbeat values. During the test, heart rate is auscultated and timed every minute beginning at 1:30. The duration of time for 30 heartbeats is recorded. Validity coefficients o the Astrand Rhyming Test ranged from .34 to .94 with the average being .64. The test-retest reliability coefficients were acceptable for older men (r = .835) and college women (r = .87) (Mierke, 2003). The main advantage of lab tests such as this is the ability to control the surroundings of the testing environment (i.e., temperature and motivation) as well as the more precise and accurate measurements obtained. Another advantage of this test is the short duration of only 6 minutes. Some disadvantages of this test include the use of expensive equipment that often malfunctions. One major limitation of this test included the reverse procedure of counting 30 heartbeats and recording the time. Obtaining heart rates is very difficult during this test since rates were taken as the subject continued to exercise. The heartbeats were often mistaken for movements of the head and neck or the heart rate was so rapid it was difficult to count (Adams, 2002; Mierke, 2003). The YMCA Bike Test is similar to the Astrand Rhyming Test in predicting maximal oxygen consumption (VO2 max) based upon the steady-state heart rate during exercise. The YMCA Bike Test lasts for 12 minutes. Heart rate is measured in how many beats per 15 seconds and multiplied by 4. The initial resistance load is .5 kp and may increase based on heart rate measurements at the end of the third minute. Subsequently, the resistance load is then increased every three minutes (i.e., load settings based on a chart) until the end of the test. VO2 max may be determined from the estimated workload at maximal heart rate (i.e., determined graphically from two points on linear scale of heart rate vs. workload produced) (Mierke, 2003). Taking heart rates between 110 and 150 b/min proves the most linear and accurate. The main advantage of this test is that it is easy to administer. The heart rate measurements of this test are also easy to obtain from the heart rate monitor worn by the subject. One disadvantage of the YMCA Bike Test is the duration of test time, 12 minutes (Mierke, 2003). Field tests for aerobic capacity Three most common field tests for determining aerobic capacity are: the PACER (Progressive Aerobic Cardiovascular Endurance Run), the one-mile run, and a walk test (for adolescents 13 years of age or older). Two of these tests estimate aerobic capacity from running performance and participant characteristics such as age, gender, body weight and the ratio of weight to height, and the third estimates aerobic capacity from heart rate response to a one-mile walk and selected subject characteristics (Cureton and Plowman, n.d.). The PACER is a multistage test adapted from the 20-meter shuttle run test published by Leger and Lambert (1982) and revised in 1988 (Leger et al.). It involves running back and forth across a 20-meter course in time to music played from a tape or CD. Beeps on the sound track indicate when a person should reach the ends of the course. The test begins at a slow pace, and each minute the pace increases. A participant continues running until the pace can no longer be maintained (Cureton and Plowman, n.d.). This test is like a graded exercise test on the treadmill in which the treadmill speed is increased at regular intervals. The longer a person continues, the higher the rate of estimated oxygen uptake. VO2max is predicted from the highest speed attained on the test and age using a regression equation of Leger et al. (1988) developed on a large sample of children 8 to 19 years of age. The main advantage of PACER is that it is more fun than the run test and is more accurate than other field test. It is highly recommended for children, adolescents and young adults (Cureton and Plowman, n.d.). In the one-mile run test, the objective is to run a mile as fast as possible. Because the rate of oxygen uptake is related in part to the pace sustained, it is possible to estimate the highest rate of oxygen uptake possible from the average pace sustained. Aerobic capacity is predicted from mile time, age, gender and body mass index using an equation developed on a large sample of children and adolescents (Cureton and Plowman, n.d.). One of the main disadvantages of this field test is that the accuracy of the aerobic capacity is affected by the age, gender and body fatness of the participant. In the one-mile walk test, the objective is to walk one mile as fast as possible. The heart rate is determined immediately after the walk. By knowing body weight and the walk speed, the primary determinants of the oxygen uptake during walking, and the heart rate at the end of the walk, indicative of the percentage of the aerobic capacity being used, it is possible to estimate the aerobic capacity (Cureton and Plowman, n.d.). Aerobic capacity is estimated from age, gender, weight, mile walk time and heart rate at the end of the walk which has been shown to be accurate for high school students (McSwegin, Plowman, Wolff, & Guttenburg, 1998). The main advantage of this test is that it does not require a maximum effort as is required in the two running tests (Cureton and Plowman, n.d.). Moreover, the 1.5 Mile Run is a field test allows test administration to many subjects at once with minimal equipment and ease of administration. One disadvantage of using this test is that it is not a direct measure of maximal oxygen consumption, merely an estimate of one's fitness level. Another disadvantage of using this test lies in the inability to control surroundings. The testing area may have conditions such as wind or cool temperatures that may not be controlled (Adams, 2002). This test is applicable to all ages if deemed physically fit, but especially suited for college age or 13 to 17 year olds (Mierke, 2003). The Rockport Walk Test reported a validity of .93. The reliability of this test may be affected by a learning effect from the first to the third trial. Like the 1.5 Mile Run, this test has the advantage of simultaneous test administration to many subjects at one time with minimal equipment and ease of administration. This test is applicable to all ages if deemed physically fit and may be especially suitable for middle to older age adults, as walking is less stressful on the joints. Disadvantages of using this test include inability to control surroundings and the fact that this test is not a direct measure of maximal oxygen consumption, merely an estimate of one's fitness level (Adams, 2002; Mierke, 2003). Recommendations Field test are more reliable than laboratory test. The reliability of the three field tests of aerobic capacity is, for the most part, high. Furthermore, consistently high reliability coefficients have been reported for the PACER and mile walk test. High coefficients also have been reported for children over 9 years of age for distance runs such as the one-mile run. However, reliability of distance runs in younger children is lower, probably because of variation in motivation and pacing. Four studies have reported that the reliability of the PACER test in youth is high. Reliability coefficients were above .84 with no significant mean differences between two tests (Cureton and Plowman,n.d.). Future research on aerobic capacity With the advent of genetic engineering, future research on aerobic capacity will be based on advance genetic knowledge. Furthermore, the advancement in microchip technology also would improve the accuracy and portability of present day testing equipments. "The reality of having a genetic determinant of our existence is that there are some people who are born with less ability to take up oxygen and transfer energy than others," says Steven Britton, professor of physical medicine and rehabilitation at the University of Michigan, in the release. "These people may have to work harder and will never reach the level of a professional athlete, but almost everyone can improve their aerobic capacity and health status with regular exercise (Warner, 2005)." The most important finding of recent research was that low exercise capacity is closely associated with higher levels of various risk factors for heart disease and diabetes, such as higher elevated fasting sugar, triglycerides, higher insulin levels, and abdominal fat (Warner, 2005). Reference List Adams, G.(2002). Exercise Physiology: Laboratory Manual. (4th ed.). Fullerton: McGraw Hill. Astrand, P.O., & Rodahl, K. (1986). Textbook of work physiology. New York: McGrawHill. Cureton, Kirk J. & Sharon A. Plowman, (n.d.). Aerobic Capacity Assessments [online]. Available from: [Dec. 29, 2005]. Leger, L.A., & Lambert, J. (1982). A maximal multistage 20m shuttle run test to predict VO2max. European Journal of Applied Physiology and Occupational Physiology, 49, 1-12. Leger, L.A., Mercier, D., Gadoury, C., & Lambert, J. (1988). The multistage 20 metre shuttle run test for aerobic fitness. Journal of Sports Sciences, 6, 93-101. McArdle, W., Katch, F., Katch, V.(2001). Exercise Physiology. (5th ed.). Baltimore: Lipincott Williams & Wilkins. McSwegin, P.J., Plowman, S.A., Wolff, G.M., & Guttenberg, G.L. (1998). Measurement in Physical Education and Exercise Science, 2, 47-63. Mierke, Ken., (2003). Aerobic Capacity Training: Maxing the VO, Available from: [Dec. 29, 2005]. Mitchell, J.H., Sproule, B.J., & Chapman, C.B. (1958). The physiological meaning of the maximal oxygen intake test. Journal of Clinical Investigation, 37, 538-547. Taylor, H.L., Buskirk, E., & Henschel, A. (1955). Maximal oxygen uptake as an objective measure of cardiorespiratory performance. Journal of Applied Physiology, 8, 73-80. Taylor, H.L., Buskirk, E., & Henschel, A. (1955). Maximal oxygen uptake as an objective measure of cardiorespiratory performance. Journal of Applied Physiology, 8, 73-80. Warner, Jennifer, (2005). Aerobic Exercise Capacity May Be Genetic, Available [Dec. 29, 2005]. Read More