MISSION/STUDY INFORMATION

This bedrest study was conducted at the Flight Analogs Research Unit (FARU) located at the University of Texas Medical Branch (UTMB) in Galveston, Texas. Subjects were recruited, screened, and upon approval, placed in the bedrest facility for testing and data collection. This study utilized 70 days of 6 degrees head-down bedrest. The study consisted of 13 days of pre-bedrest for the non-exercise group and 21 days of pre-bedrest for the exercise group, as well as 14 days of post-bedrest. Head-down tilt bedrest relieves longitudinal gravitational loading of the cardiovascular, bone, and muscle systems. Healthy subjects exposed to prolonged bedrest experience some of the adaptive physiological responses and associated deconditioning seen in astronauts exposed to prolonged weightlessness.

This study consisted of the integration of standard measures and visual monitoring with investigator study protocols: The focus of this bedrest study was countermeasures and functional testing focusing on the key physiological factors that contribute to changes in performance of a set of functional tasks that are representative of critical mission tasks for planetary operations.

The study also focused on the feasibility and efficacy of a new integrated resistance and aerobic training (iRAT) exercise countermeasure program designed to protect cardiovascular, muscle and bone health. The first 27 subjects (A-E): aerobic exercise sessions were completed on the supine cycle ergometer and the Standalone Zero-Gravity Locomotion Simulator (sZLS). A minimum of two-thirds of the total aerobic sessions were performed on the sZLS and the balance was performed on the cycle ergometer. Resistance exercise was performed three days per week, every other day using a prone leg curl, horizontal leg press, and horizontal squat machine (i.e. HEF). For the last 8 subjects (F) squat exercises previously performed on the Horizontal Squat Device were performed on the M-MED. The. leg press, heel raise, and hamstring curl previously performed on their specific devices were performed on the M-MED. Rowing exercise replaced the running and cycling exercises performed on the sZLS and supine cycle. Rowing was performed as interval and continuous sessions. The campaign incorporated the study "Surveillance of Ocular Parameters and Visual Function in Bedrest Subjects". This study objective was to assess the safety of prolonged head-down tilt on ocular health and to comply with the requirements of a Data Safety Monitoring Board (DSMB). This study utilized the Flight Analog Program (FAP) Standard Measures collection, with modifications to achieve inter-study compatibility and facilitate the implementation of individual research protocol objectives.

In addition to the Standard Measures testing used during bedrest studies at UTMB; external investigations were included with the study science requirements:

• Physiological Factors Contributing to Postflight Changes in Functional Performance: Bedrest Analog Study.
(PI: Bloomberg, Jacob J., Ph.D. Neuophysiology Laboratory, NASA Johnson Space Center, Houston, Texas)

• Integrated Resistance and Aerobic Training Study – Bedrest.
(PI: Ploutz-Snyder, Lori, PhD, University Space Research Association (USRA), Houston, Texas)

• Effects of Retronasal Smelling, Variety, and Choice on Appetite and Satiety.
(PI: Hunter, Jean B., PhD Associate Professor, Agricultural and Biological Engineering Cornell University, Ithaca, NY)

• Testosterone Supplementation as a Countermeasure against Musculoskeletal Losses during Space Exploration.
( PI: Urban, Randall, M.D., Internal Medicine, University of Texas Medical Branch (UTMB), Galveston, Texas)

• Surveillance of Ocular Parameters and Visual Function in Bed Rest Subjects (Ocular_Test).
(PI: Ronita Cromwell, Ph.D. USRA, NASA Johnson Space Center, Houston, Texas and PI: Gianmarco Vizzeri, M.D., University of Texas Medical Branch, Galveston, Texas)
The Data Safety Monitoring Board (DSMB) reviewed data accumulated on 16 subejcts on the 14 day Campaign 17 study, and nine subjects on the 70 day Campaign 11 study. It was concluded that there were no significant safety issues based on the review of the data. A consensus decision was reached by the DSMB to conclude this study.

• Bed Rest as a Spaceflight Analog to Study Neurocognitive Changes: Extent, Longevity, and Neural Bases (NCC958SA02802).
(PI: Rachael Seidler, Ph.D. University of Michigan, Ann Arbor, Michigan)

• AD ASTRA: Automated Detection of Attitudes and States through Transaction Recordings Analysis (NNX12AB40G).
(PI: Christopher Miller, Smart Information Flow Technologies, LLC, Minneapolis, Minnesota)