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Influence of Exercise Modality on Cerebral-Ocular Hemodynamics and Pressures (Exercise_Modality)
Principal Investigator
Research Area:
Biomedical countermeasures
Exercise physiology
Ocular physiological phenomena
Species Studied
Scientific Name: Homo sapiens Species: Human

Seventy-six percent of long-duration astronaut crewmembers have experienced inflight and/or postflight vision changes. These changes define what has become known as space flight-associated neuro-ocular syndrome (SANS). Although the exact cause of SANS is unknown at this time, it is suspected that the microgravity-induced shift in fluids from the lower body to the upper body (cephalad fluid shift) plays a significant role. This fluid shift, in turn, may cause an elevation in intracranial pressure (ICP) and intraocular pressure (IOP).

Another factor that has been proposed to contribute to SANS is exercise. Although moderate and high intensity aerobic or resistance exercise have clearly identified benefits for cardiac, muscle, and bone health, it is unknown whether such exercise contributes to the development of SANS. The objective of this study was to characterize the impact of three exercise modalities used by astronauts on cerebral blood flow (CBF), ICP, and IOP.

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Scott JM, Tucker WJ, Martin D, Crowell JB, Goetchius E, Ozgur O, Hamilton S, Otto C, Gonzales R, Ritter M, Newby N, DeWitt J, Stenger MB, Ploutz-Snyder R, Ploutz-Snyder L, Morgan B, and Haykowsky MJ. Association of exercise and swimming goggles with modulation of cerebro-ocular hemodynamics and pressures in a model of spaceflight-associated neuro-ocular syndrome. JAMA Ophthalmology. 2019. June 1; 137(6):652-9. [DOI]

Head Down Tilt
Exercise test

Data Information
Data Availability
Archive is complete. Data sets are not publicly available but can be requested.
Data Sets+ Request data

Blood flow, common carotid artery (CCA)
Blood flow, external carotid artery
Blood flow, internal carotid artery
Blood flow, internal jugular vein (IJG)
Blood flow, vertebral vein
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Mission/Study Information
Mission Launch/Start Date Landing/End Date Duration
Ground 05/01/2009 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.

The Human Research Roadmap is located at:

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Additional Information
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Institutional Support
National Aeronautics and Space Administration (NASA)
Alternate Experiment Name
Proposal Date
Proposal Source
2013 HERO NNJ13ZSA002N-Crew Health OMNIBUS