VO2max Lab: Examining the Impact of Fitness Level on Cardio-Respiratory Fitness, Summaries of Physiology

Download VO2max Lab: Examining the Impact of Fitness Level on Cardio-Respiratory Fitness and more Summaries Physiology in PDF only on Docsity!

N. Draper, C. Williams, H. Marshall,

Physiology of exercise

Running head: VO2MAX LAB 1 VO2max Lab University of Maryland College Park, Maryland

For the purposes of this study, a 20-year-old female athlete was chosen as a primary participant for experimentation. The subject was 5’3” and weighed 134lbs at the time of the experiment. The participant of this study was examined using the FITT criteria, as outlined in the protocol of the experiment. She self-reported that she exercised 20 hours per week at a high intensity, and also that she was a gymnast. Additionally, this study includes the examination and comparison of the primary participant and a sedentary participant, whose data was provided by the lab coordinator. Materials: This experiment required materials in order to properly measure the participants VO2max. We used a VO2max application through a Cosmed machine to record the individuals trial. A treadmill was required as the mode of exercise for the experiment. Also, respiratory equipment was required, which included a combitox mask, respiratory valve, turbine, mouthpiece, air volume meter in the form of a Tissot Tank and dry gas meter, and a sampling line. We also required a stadiometer, scale, stopwatches and a heart rate monitor. Measures: This experiment looks to measure the VO2max of the given participant. The independent variable in this trial is speed and incline of the treadmill, while the dependent variable is oxygen consumption, found through the measurement of VO2max. Procedures: The lab technician was responsible for several of the pre-test conditions and steps. Prior to the test, they sterilized and set up the mouthpiece. Additionally, they calibrated the Cosmed machine, treadmill, and metabolic cart. Further, they ensured that the test room’s temperature,

humidity, and barometric pressure were suitable for experimentation. This is important because unsuitable room conditions could cause an error in our results. Prior to the onset of the exercise stages, the participant was subject to a pre-test. The pre-test included the measurement and recording of their height, weight, and physical activity status (FITT). Additionally, adjustments were made to the headgear so that the mask was snug on their face and provided the most accurate reading of oxygen transmission. A brief warm-up of walking was done by the participant for approximately 4 seconds before stage 1 of the trial began. The Modified Bruce protocol was utilized in this test. The participant was to complete several 2-minute stages at a speed which increased by 1 mile per hour and 2% incline per interval. The goal was to have the subject reach their VO2max within 6 - 12 minutes of the onset of stage 1. Lab volunteers were responsible for recording the heart rate and rate of perceived exertion (RPE) during the last 15 seconds of each stage. Non-verbal cues were given by the participant to indicate their RPE during the trial, by pointing to a physical Borges scale. Also, a treadmill spotter was utilized during the test to ensure the participant’s safety during the trial. Considerations of the test included non-verbal communication with the participant as to not cause an error in the measurement of oxygen consumption being tracked by the respiratory equipment. Also, the subject was given time to adjust to their current conditions before their RPE was recorded. Contradictions for the test include the subject reporting RPE above 17 or their RER being greater than 1.15. The subject may also quit the test at any time for various reasons prior to the VO2max being reached. The test will be considered successfully completed if the individuals VO2max is reached within the pre-established parameters.

Results Based on the results of our experiment, it appears that there is a correlation between an individual’s FITT status and their overall cardio-respiratory fitness. For subject 1, who is a trained athlete, we see a significantly higher absolute and relative vo2max than subject 2, who is primarily sedentary as characterized in table 1. With this, we also see that the endurance capacity of each subject was different during the trial. Although we did not get a VO2max for subject 1 we can safely assume that it would be much greater than subject one by comparing the incremental changes of relative VO2max in tables 1 and 2. Additionally, we found that the endurance capacity of subject 1 was greater than that of subject 2. Discussion In agreeance with our results, similar studies have found that VO2max is a successful measure of cardio-respiratory fitness. As seen through our data, the participant who was healthy and trained, had a higher absolute and relative VO2max in comparison to the healthy yet sedentary participant. Marti and Howald found that athletes who were trained had higher VO2max values which remained true over a 15-year period which adjusted for decreased heart rate with age (1990). Furthermore, through our study, we were able to confirm that RER was well correlated to an individual’s fitness level. The findings of Ramos-Jiménez et al., also found that there were significant differences in trained and untrained individual’s RER, which means that RER can be used as an indicator of an individual’s fitness (2008). Factors that may contribute to an individual’s VO2max are their genetics, age, FITT status, gender, and body composition. In this study, it is assumed that majority of the factors that contributed to the difference in the participant’s VO2max values are their FITT status, as this is the most notable difference between the two subjects. One of the subjects was a highly trained athlete and we

believe that this was the primary cause of her increased VO2max in comparison to the sedentary participant. Based on our assertion that habitual physical activity positively affects cardio- respiratory fitness, our results would support this and are what we expected to see. With these individuals, we see that cardio-respiratory fitness is a determinate of the endurance an individual has. For example, in Table 1 the participant was able to continue the test for a longer period of time as their VO2max was not obtained as quickly as the participant shown in Table 2. Training is able to increase the individual’s VO2max, which makes it apparent that training is beneficial to increasing the body’s ability to increase oxygen consumption, especially at maximal levels. Based on all of the available data it appears that we were only able to achieve a true VO2max value for participant 2. This participant's data satisfied two of the criteria that we look for in a true VO2max test. This participants VO2 reached a plateau and failed to increase by 0.15 L/min with increased intensity, and their RPE was greater than 17. For participant 1, we were not able to obtain a value for their true VO2max, however, we were able to obtain a VO2peak. The difference between a VO2max and VO2peak is that a VO2max is the maximal oxygen consumption that an individual is capable of, whereas a VO2peak is the highest amount of oxygen consumption that an individual exhibited during a certain test or period. All tests will have a VO2peak, however, all tests may not successfully yield a VO2max if the necessary criteria are not meet during the test.