Standard Operating Procedure for Prediction of VO2max Using a Modified Astrand (1960) Protocol

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Standard Operating Procedure for Prediction of VO2max Using a Modified Astrand (1960) Protocol Effective date: 31.10.2016 Review due date: 30.08.

1 Standard Operating Procedure for Prediction of VO2max Using a Modified Astrand (1960) Protocol Effective date: Review due date: Original Author Name: Richard Metcalfe Position: Ph. D. Student Date: Reviewer Name: Ben Lee Position: Physiology Lab Technician Signature: Date: Approved by Name: Prof Keith Stokes Position: Deputy Head of Department Signature: Date: Amendment Chronology Version Effective Reason for amendment Reviewed/Amended by number date First issue Richard Metcalfe No amends Ben Lee Version: 2 Effective date:

2 Prediction of VO 2max Using a Modified Astrand (1960) Protocol The test is a modified version of that described by Astrand (1960). The data collected can be used in three different ways to give values for VO2max. This will allow you to compare the accuracy of different methods of prediction and actual measurement of VO2max. The protocol requires maximal effort and the participant will exercise at a constant treadmill speed but the gradient will be increased progressively during the test. This test will be performed using gas analysis for direct determination of VO2max and also to do a sub-maximal prediction of VO2max using a graphical extrapolation of sub-maximal VO2 and heart rate values to a predicted value. Pre-test information As with all of the predictive tests ensure that participants have adhered to the pre-testing guidelines regarding drinking and eating and that they have completed a generic consent form. You will have noticed that this form asks questions relating to the health of the participant. Check these questions carefully to ensure that the participant is feeling healthy prior to undertaking any test. Experimental protocol 1. Weigh the participant and record weight on the form. The participant should wear light clothing and appropriate training shoes. 2. Ask the participant to warm-up on the treadmill for 5 minutes at 5.6 km/h and with a 2.5% grade. 3. Select a treadmill speed, at which the participant is running comfortably but that with increasing gradient will be exhausted in 7-12 minutes. This should be a hard but comfortable running speed for the participant. 4. Fit the participant with the mouthpiece and nose clip and let them stand on the treadmill for a couple of minutes to collect some baseline expired air. Version: 2 Effective date:

3 5. Ensure that the participant is not standing on the treadmill belt (feet should be either side of the belt). Start the treadmill and follow the protocol given in Table I. 6. Tell the participant that he/she will be exercising continuously at increasing workloads until exhaustion. 7. When the participant starts to exercise and hands are free from the treadmill handrail start the clock. 8. Record the participants heart rate at the end of every work stage 9. Exhaustion is defined as the point where the participant can no longer continue to exercise at the defined workload. 10. At the end of the test allow the participant to walk at an easy pace on the treadmill for a couple of minutes or until they feel able to move from the treadmill. Confirmation of VO2max 1. After a further 5 minutes of rest increase the treadmill incline by 1% from the final workload. 2. Ask the participant to run at their last pace and the new load for as long as possible with the mouthpiece and nose clip attached. NOTE: If the participant feels light headed at any time during the test or feels that they wish to stop prior to exhaustion the tests should be terminated and they should lie down on a mat with the feet elevated for approximately 5 minutes. Version: 2 Effective date:

4 TABLE 1 Experimental protocol STAGE TIME (min) SPEED (km/h) GRADIENT (%) No speed is given, as this will be specific to each individual subject. Ensure that it is not too fast or too slow as this will result in either too short or too long test duration. Data analysis On completion of the test ensure that you have all the data recorded properly and collect the printout from the on-line gas analysis machine. You are going to use three methods to determine VO2max of the participant. Method 1 Maximal direct determination This method uses the results of the on-line gas analysis. You should study the data collected carefully to determine the direct determination of VO2max. The BASES criteria for a valid direct determination of Maximal oxygen uptake are: A change of less than 2 ml.kg -1 min -1 between the last minute of the test and the last minute of the previous workload. An RQ of more than 1.15 at the end of the test. A final heart rate of 5 beats of predicted max heart rate (220 - Age) Version: 2 Effective date:

5 In addition the confirmation test value should be less than or the same as that ascertained during the actual test. If it is greater, then it is presumed that the test was not maximal. Method 2 Sub-maximal extrapolation This method uses the same data from the on-line gas analysis. However instead of considering all the data you will only consider that of the first few workloads of the test. This is what you could do if for example you did not have ethical clearance to exercise maximally or your participant population was unable to exercise maximally. You should record the heart rate and VO2 data in the table provided for all stages where the end heart rate was less than 85% of the age predicted max (220 - age), at least three data points are required. Then on the graph paper provided you should plot heart rate against VO2 and extrapolate the line to age predicted max heart rate. This allows you to predict the participant s VO2max from a sub-maximal test. Method 3 Maximal prediction This method can be done without gas analysis so you do not need these results. Using the speed and gradient of the treadmill at exhaustion of the participant you should use the equations in Table 2 to predict the oxygen cost of the maximal exercise. Version: 2 Effective date:

6 TABLE 2 Equations for conversion of treadmill speed and gradient into oxygen cost of exercise (Method 3) Work through all of the equations and calculate the oxygen cost of exercise at the end of each workload during the protocol. 1) Convert speed in km h -1 to metres min km h -1 = metres min -1 2) Calculate the horizontal component (HC) of oxygen cost. HC = speed (metres min -1 ) x 0.2 3) Calculate the vertical component (VC) of oxygen cost. VC = (grade (%)/100) x speed (metres min -1 ) x 0.9 4) Calculate the oxygen cost of exercise (VO2) in ml kg -1 min -1 by adding the HC and VC and adding a correction factor for a resting component (REST = 1 MET = 3.5 ml kg - 1 min -1 ) VO2 = HC + VC + REST (American College of Sports Medicine s Guidelines for exercise testing and prescription. 6 th. edition 2000) References Astrand, I. (1960). Aerobic work capacity in men and women with special reference to age. Acta. Physiol. Scand. 49 (suppl. 169.) End of Document Version: 2 Effective date:

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