Original Article

Osteoporosis International

, Volume 24, Issue 7, pp 2105-2114

First online:

Bisphosphonates as a supplement to exercise to protect bone during long-duration spaceflight

  • A. LeBlancAffiliated withUniversities Space Research Association Email author 
  • , T. MatsumotoAffiliated withDepartment of Medicine and Bioregulatory Sciences, Graduate School of Medical Sciences, University of Tokushima
  • , J. JonesAffiliated withCenter for Space Medicine, Baylor College of Medicine
  • , J. ShapiroAffiliated withKennedy Krieger Institute
  • , T. LangAffiliated withDepartment of Radiology, University of California
  • , L. ShackelfordAffiliated withHuman and Adaptation Countermeasure Division NASA Johnson Space Center
  • , S. M. SmithAffiliated withHuman and Adaptation Countermeasure Division NASA Johnson Space Center
  • , H. EvansAffiliated withWyle
  • , E. SpectorAffiliated withWyle
    • , R. Ploutz-SnyderAffiliated withUniversities Space Research Association
    • , J. SibongaAffiliated withHuman and Adaptation Countermeasure Division NASA Johnson Space Center
    • , J. KeyakAffiliated withDepartment of Radiological Sciences, University of California
    • , T. NakamuraAffiliated withDepartment of Orthopedic Surgery, University of Occupational and Environmental
    • , K. KohriAffiliated withDepartment of Nephrology, Nagoya City University
    • , H. OhshimaAffiliated withJapan Aerospace Exploration Agency

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We report the results of alendronate ingestion plus exercise in preventing the declines in bone mass and strength and elevated levels of urinary calcium and bone resorption in astronauts during 5.5 months of spaceflight.


This investigation was an international collaboration between NASA and the JAXA space agencies to investigate the potential value of antiresorptive agents to mitigate the well-established bone changes associated with long-duration spaceflight.


We report the results from seven International Space Station (ISS) astronauts who spent a mean of 5.5 months on the ISS and who took an oral dose of 70 mg of alendronate weekly starting 3 weeks before flight and continuing throughout the mission. All crewmembers had available for exercise a treadmill, cycle ergometer, and a resistance exercise device. Our assessment included densitometry of multiple bone regions using X-ray absorptiometry (DXA) and quantitative computed tomography (QCT) and assays of biomarkers of bone metabolism.


In addition to pre- and post-flight measurements, we compared our results to 18 astronauts who flew ISS missions and who exercised using an early model resistance exercise device, called the interim resistance exercise device, and to 11 ISS astronauts who exercised using the newer advanced resistance exercise device (ARED). Our findings indicate that the ARED provided significant attenuation of bone loss compared with the older device although post-flight decreases in the femur neck and hip remained. The combination of the ARED and bisphosphonate attenuated the expected decline in essentially all indices of altered bone physiology during spaceflight including: DXA-determined losses in bone mineral density of the spine, hip, and pelvis, QCT-determined compartmental losses in trabecular and cortical bone mass in the hip, calculated measures of fall and stance computed bone strength of the hip, elevated levels of bone resorption markers, and urinary excretion of calcium.


The combination of exercise plus an antiresoptive drug may be useful for protecting bone health during long-duration spaceflight.


Bisphosphonates Bone loss Computed bone strength Exercise QCT Spaceflight