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Evaluation of Maximal Oxygen Consumption (VO2PK) Protocols for Determining Ventilatory Threshold (EORS_VT)
Principal Investigator
Research Area:
Cardiovascular physiology
Species Studied
Scientific Name: Homo sapiens Species: Human

VO2pk is traditionally considered the best measure for evaluation of cardiorespiratory fitness. However, literature suggests that ventilatory threshold (VT) may be a better predictor of aerobic fitness, specifically with respect to performing submaximal work over a long period of time. Determining VT in combination with VO2pk could provide valuable information regarding crewmembers’ ability to perform extravehicular activity (EVA) and lunar exploration.

VO2pk is measured by an incremental exercise cycle test whereby subjects begin at very light warm up loads and the workload is gradually increased until maximum; optimal test time is 8-15 minutes, thus requiring different incremental exercise protocols based on subject characteristics (body size, fitness, gender, etc). It is generally believed that optimal testing involves small gradual increases in workload versus fewer large steps in workload. Assessment of VT requires small gradual increases in workload, thus the investigators proposed to pilot test four different "ramp" protocols.

The primary purpose of this study was to identify a peak cycle protocol that elicits a true VO2pk and allows for the determination of VT in subjects of varying gender, body weight, and training status. In order to meet this objective a method for technicians to determine whether VO2pk was achieved and for identifying VT needed to be defined.

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Oxygen consumption
Carbon dioxide (CO2)

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Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
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Heart rate
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
ECP 02/01/2005 12/31/2010 In Progress

Human Research Program (HRP) Human Research Roadmap (HRR) Information
Crew health and performance is critical to successful human exploration beyond low Earth orbit. The Human Research Program (HRP) investigates and mitigates the highest risks to human health and performance, providing essential countermeasures and technologies for human space exploration. Risks include physiological and performance effects from hazards such as radiation, altered gravity, and hostile environments, as well as unique challenges in medical support, human factors, and behavioral health support. The HRP utilizes an Integrated Research Plan (IRP) to identify the approach and research activities planned to address these risks, which are assigned to specific Elements within the program. The Human Research Roadmap is the web-based tool for communicating the IRP content.

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Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Pamela A. Bieri
Institutional Support
National Aeronautics and Space Administration (NASA)
Proposal Date
Proposal Source
Directed Research