Comparing VO2 Max Results with Astrand and YMCA Tests - Lab Report Example

Running Head: LABORATORY REPORT Dennis Vivian Emmanuel The Laboratory Report defines VO2 Maxand describes the physical and chemical changes involved in the process of attaining the defined. It also defines the representation of VO2 Max and how it is calculated. A comparison of VO2 Max Test with Astrand (LaB2) AND YMCA Test is explained. It also highlights the limitations of Sub-Maximal over Maximal Exercise testing. Comparison of EVC, EFV 1 /FVC in normal case, case of Obstructive pulmonary disease & Restrictive pulmonary diseases explained. Lastly it highlights the differences in the FVC. FEV1 or FEV 1 / EVC % ration between males and females. VO2 Max is defined as the Maximum capacity of a body to transport and utilize Oxygen while exercising or doing some excessive physical activity. It is also termed as Maximum Oxygen Consumption/uptake. Maximal Test is used to calculate the VO2 Max Achieved by a person (usually athletes). PHYSIOLOGY There are 3 main factors governing the Maximum Oxygen transport: 1. CARDIAC OUTPUT: It is calculated as = (Heart Rate) X (Stroke Volume) Heart Rate is defined as the number of heart contractions in 1minute and Stroke Volume is the amount of blood ejected by heart in each beat. Cardiac output in a resting individual of average size is about 5 liters/minute. In an untrained individual heart rate is about 72 beats per minute so stroke volume is about 70 milliliters. 2. OXYGEN CARRYING CAPACITY OF BLOOD: Hemoglobin present in our Red Blood Cells binds the Oxygen present in the blood and forms Oxyhemoglobin during pulmonary circulation. The blood is circulated to different parts of the body including skeletal muscles. 3. SKELETAL MUSCLE MASS: Of the three factors determining maximum oxygen consumption, the most important is the role of skeletal muscle. The larger the mass of exercising skeletal muscle , greater the potential for increasing whole body oxygen consumption. Example: A runner running on a treadmill at a given speed requires certain amount of oxygen. If he increases the speed, the amount of oxygen required would also increase. The runner keeps increasing the speed and hence the corresponding oxygen requirement also increases until a point is reached where he can't increase the speed. The volume of Oxygen used by muscles at that point is optimum which is defined as VO2 Max. EXPLAINING VO2 MAX TO A LAYMAN VO2 Max: - V= Volume, O2 =Oxygen & Max= Maximum VO2 Max is calculated in "ml/Kg/min" Example: If my client is 24Year old and his VO2 Max is 24 ml/Kg/m, As for a layman I will explain him that in 1 minute, 1 Kg of his body weight consume a maximum of 24 ml of oxygen to provide energy. COMPARING VO2 MAX RESULTS WITH ASTRAND AND YMCA TESTS GREIWE, J. S., L. A. KAMINSKY, M. H. WHALEY, and G. B. DWYER. Evaluation of the ACSM sub maximal ergo meter test for estimating VO2max. Med. Sci. Sports Exerc. Vol. 27, No. 9, pp. 1315-1320, 1995. The purpose of this investigation was to assess the reliability and validity of maximal oxygen uptake estimates (ESTmax) from the ACSM sub maximal cycle ergo meter test. Subjects included 15 men and 15 women aged 21-54 yr who performed two sub maximal tests and one maximal cycle ergo meter test to determine maximal oxygen uptake (VO2max). During the sub maximal tests, heart rates (HR) were recorded from a radio telemetry monitor. ESTmax was predicted for both sub maximal trials by extrapolating HR to an age-predicted maximal HR. Correlation coefficient and standard error of measure (SEmeas) for ESTmax between submaximal trials were r = 0.863 and SEmeas = 0.40 l. min-1, while a t-test revealed no significant difference between trials. Although trial means were not significantly different, large variation in individual cases was evident by the high SEmeas (0.40 l.min-1) and by a large SEmeas expressed as a percentage of the mean (13%). The mean of the two ESTmax significantly overestimated measured VO2max with percent error, total error, and mean error equal to 25.7%, 0.89 l. min-1, and 0.63 l.min-1, respectively. The standard error of estimate expressed as a percentage of the mean was equal to 16% and 15% for both ESTmax. In summary, the ACSM protocol failed to be reliable as represented by the large differences found between submaximal trials. Furthermore, the protocol significantly estimates VO2max and should not be used when an accurate assessment of VO2max is required. LIMITATIONS OF SUB MAXIMAL Vs MAXIMAL EXERCISE TEST Accuracy is high (about 95%) in Maximal tests as comapred to Sub Maximal. In a sub max test there are a number of assumptions: From (Kinesiology 337A, 1998) 1. A Linear relationship exists between heart rate, oxygen intake and workload. 2. There is a similar max heart rate for any person at a given age. 3. Mechanical efficiency is the same for everyone. EVC, FEV1/FVC RATIO Obstructive pulmonary diseases are abnormalities in airflow that are the result of disease of the inside (called the lumen) of the airway. Since it is hard to exhale with obstructive disorders, the flow rate is reduced as reflected by a reduced FEV1 and possibly a reduced FVC. The increase in FEV1 causes the FEV1/FVC ratio (normally 70-75%) to be less than 70%. In obstructive lung diseases the decrease in FEV1 is greater relatively to the decrease in FVC and that is why the FEV1/FVC ratio is low In Restrictive pulmonary disease. On the other hand, Restrictive pulmonary diseases are abnormalities of the lung tissue itself or the capacity of the lungs to expand. Fibrosis (i.e. scar tissue replacing normal lung tissue) and physical deformities are examples of restrictive disorders. Since it is hard to inhale with restrictive disorders, the air volume is reduced as reflected by a reduced FVC and possibly a reduced FEV1. The decrease in FVC is much greater than the decrease in FEV1 and this causes the FEV1/FVC ratio (normally 70-75%) to be greater than 80% FEV1 or FEV 1 / EVC % RATION IN MALE AND FEMALE One hundred and thirty-seven patients aged 15-50 years made 196 consecutive visits to the authors' ED over 6 months. The ratio of female: male patients was 19 and the ratio of the number of visits made by female vs. male patients was 26. Initial peak expiratory flow rate (PEFR) and forced expiratory volume in 1 s (FEV1) were recorded in 94% and 49% of the visits, respectively. There was no statistically significant difference between the male and female patients in heart rate, respiratory rate or percentage of patients admitted to hospital. The mean () initial FEV1 as a percentage of predicted was significantly higher in females compared to males (49% 20% vs. 33% 15%; P Read More