Retrospective Analysis of Inflight Exercise Loading and Health Outcomes (Inflight_Loading)
Scientific Name: Homo sapiens Species: Human
Astronauts perform treadmill exercise during long-duration space missions to counter the harmful effects of microgravity exposure upon bone, muscle, and cardiopulmonary health. When exercising in microgravity, astronauts wear a harness and bungee system that provides forces that maintain attachment to the treadmill. Typical applied forces are less than body weight. The current exercise devices on the International Space Station (ISS) allow astronauts to complete prescriptions at higher intensities which potentially allow for greater exercise benefits with increased efficiency. However, although overall health outcomes have improved, the specific factors related to increased benefits have yet to be determined.
This study had the following specific aims:
- Quantify the exercise-related mechanical loading experienced by crewmembers during their mission on the ISS.
- Explore relationships between exercise loading variables, bone, and muscle health changes during the mission.
- Determine if specific mechanical loading variables are more critical than others in protecting health.
- Develop methodology for operational use in monitoring crew exercise programs.
++ -- View more
This retrospective analysis was conducted using data from seven crewmembers that were subjects in the Treadmill Kinematics study (Kinematics_T2). Crewmembers completed approximately six-month missions on the ISS and performed regular exercise on the T2 throughout their mission, although each subject’s specific prescription varied. Exercise logs and inflight ground reaction force data were summarized to quantify T2 mechanical loading occurring during flight. Mechanical loading variables were compared to bone mineral density changes to determine if relationships existed.
Results indicate that increased time and distance jogging related to improved bone health. Further investigation revealed that in the current subject pool, those who performed exercise sessions that include both running and jogging, such as during high intensity interval training, tended to have better bone-related outcomes. More study is necessary, including increasing subject size and inclusion of resistance exercise to better assess exercise relationships to bone health.
++ -- View more
Archive is complete. Data sets are not publicly available but can be requested.+ Request data
Areal bone mineral density (aBMD), femoral head
Areal bone mineral density (aBMD), left trochanter
Areal bone mineral density (aBMD), lumbar spine
Distance jogged, miles
++ -- View more
Distance run, miles
Distance walked, miles
Gravity replacement load (GRL)
Ground reaction foot force
High speed ratio
Time between footfalls
Time jogged, minutes
Time run, minutes
Time walked, minutes
Total distance, miles
Total impulse (IMP)
Total peak impact force (PIF)
Total peak propulsive force (PPF)
Total time, minutes
Treadmill workout duration
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: https://humanresearchroadmap.nasa.gov/
+ Click here
for information of how this experiment is contributing to the HRP's path for risk reduction.
Managing NASA Center
Johnson Space Center (JSC)
Responsible NASA Representative
Johnson Space Center LSDA Office
Project Manager: Eric Gallagher
National Aeronautics and Space Administration (NASA)
Similar Experiments or Analyses