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Oro-Nasal Mask Versus Two-Way Non-Rebreathing Valves for Maximal Aerobic Capacity Testing in AstronautsAstronauts complete maximal aerobic capacity (VO2pk) testing as part of their annual fitness assessment (AFA) as well as several times once assigned to an International Space Station mission. Historically, the 2-Way T-Shape Non-Rebreathing valve with a mouthpiece and nose clip (“Mouthpiece”) has been used in these tests. The testing procedure was updated to use the oro-nasal mask (“Mask”) for the AFA starting in June 2017. Astronauts who used the mask during their AFA requested it be certified to be used for all mission associated tests. Considering the criticality of the data and the schedule constraints of astronauts, it is imperative that the requested hardware change provide data with equivalent reliability and repeatability as provided by the mouthpiece. PURPOSE: To assess the reliability and validity of mask vs. mouthpiece by comparing submaximal and VO2pkdata within subjects (approximately 1 year apart). METHODS: Each of 17 active astronauts completed a VO (sub 2pk) test with the mouthpiece (first) and the mask (second) for their AFA. The VO (sub 2pk) test was conducted on a cycle ergometer with a metabolic cart. The nominal protocol started with a 3-minute warm-up at 50 Watts (W) and increased 25W every minute until volitional fatigue (Light: 45W start; 15W increase). The VO (sub 2pk)s were compared between tests and the expected day-to-day variation (plus or minus 5 percent) was used as the threshold for determining agreement between tests. Submaximal values were plotted and evaluated visually for deviations between mask and mouthpiece. RESULTS: VO (sub 2pk) values were more than 5 percent different, despite similar test times, between mouthpiece and mask in 6 of 17 comparisons, 3 of which were higher with the mask (9.0 plus or minus 5.9 percent) while 3 were lower (minus10.8 plus or minus 2.0 percent) with the mask. The submaximal data did not indicate a leak in either apparatus during these tests. An Astronaut Strength & Conditioning Rehabilitation specialist confirmed that the measured differences in VO (sub 2pk) of these 6 astronauts was consistent with observed changes in exercise habits during the year that separated the two tests. CONCLUSION: After being presented with the results of this data mining effort the mask was accepted for use in all tests, excepting that, if a leak is detected without resolve, the test will be repeated (if schedule allows) and remaining tests will be completed with the mouthpiece.
Document ID
20190027026
Acquisition Source
Johnson Space Center
Document Type
Poster
Authors
Buxton, R.
(Houston Univ. Houston, TX, United States)
Downs, M.
(Wyle Laboratories, Inc. Houston, TX, United States)
Scheuring, R.
(NASA Johnson Space Center Houston, TX, United States)
Latham, S,
(Wyle Laboratories, Inc. Houston, TX, United States)
Crowell, J.
(MEI Technologies, Inc. Houston, TX, United States)
Goetchius, E.
(Houston Univ. Houston, TX, United States)
Abercromby, A. F.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
July 3, 2019
Publication Date
May 28, 2019
Subject Category
Man/System Technology And Life Support
Aerospace Medicine
Report/Patent Number
JSC-E-DAA-TN69156
Meeting Information
Meeting: American College of Sports Medicine Annual Meeting (ACSM 2019)
Location: Orlando, FL
Country: United States
Start Date: May 28, 2019
End Date: June 1, 2019
Sponsors: American College of Sports Medicine
Funding Number(s)
CONTRACT_GRANT: NNJ15HK11B
Distribution Limits
Public
Copyright
Public Use Permitted.
Technical Review
Single Expert
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