Simulation of Weightlessness by Anti-Orthostatic Long Term Bed RestPhase 1NCT00311571
Toulouse Male Long Term Bed Rest 2001-2002
A Phase 1 study testing Ethidronate and Physical training in people with Simulation of Weightlessness by Anti-Orthostatic Long Term Bed Rest, run by Centre National d'Etudes Spatiales at 1 site in France.
Trial summary
Microgravity during space flight induces physiological changes that affect astronauts' health and performance. Space flight simulations such as prolonged bed rest can mimic some of these changes and provide study conditions that are more accessible than during space flight. Read more about this study
- Who is it for?
- Ages 25 to 45 years, men only
- Conditions the study is for
- Simulation of Weightlessness by Anti-Orthostatic Long Term Bed Rest
- What is being tested?
- Ethidronate and Physical training
- Type of treatment
- Lifestyle or therapy programme
- How many people
- 28 participants
- Where
- 1 siteFrance
- Study dates
- Aug 2001to Jun 2003
- Phase
- Phase 1
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 25 to 45 years
- Men only
- No healthy volunteers
- Adult
Who may be able to join
- Healthy male volunteer , citizen of the European Community.
- Age 25 to 45,
- Non smokers,
- No alcohol, no drug dependence and no medical treatment,
- Height 165 cm to 185 cm,
- No overweight nor excessive thinness. BMI (weight Kg/ height m2) between 20 and 27,
Show all 9Show fewer
- No personal nor family past record of chronic or acute disease which could affect the physiological data and/or create a risk for the subject during the experiment,
- Subject to be covered by a Social Security system,
- Free of any engagement during four consecutive months.
Who cannot join
- Having given blood (more than 300ml) in a period of three months or less before the start of the experiment,
- Subject already participating in a clinical research experimentation,
- Poor tolerance to blood sampling,
- Past record of orthostatic intolerance,
- Cardiac rhythm disorders,
- Allergies,
Show all 14Show fewer
- Intensive sport training,
- Fractures or tendon laceration since less than one year,
- Chronic back pains,
- Past records of thrombophlebitis,
- Presence of metallic implants,
- Special food diet,
- Sleep disorders :Lark and owl type,Subject sleeping more than 10 hours or less than 5 hours,
- Photosensitive epilepsy.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Simulation of a Mission Aboard the International Space Station by a Long Duration Anti-Orthostatic Bed Confinement at - 6° (90 Days) on Healthy Subjects:1/Perfecting of Preventive Methods (Muscular Exercise and Biphosphonates) and Evaluation of the Effects on the Locomotion and Cardiovascular Systems and on the Lipid and Energy Metabolisms. 2/Pharmacokinetic Assessment: Effects of Position on the Absorption Mechanisms: Pharmacokinetics of Paracetamol Used as Model to Study Oral Absorption in Simulated Weightlessness
Microgravity during space flight induces physiological changes that affect astronauts' health and performance. Space flight simulations such as prolonged bed rest can mimic some of these changes and provide study conditions that are more accessible than during space flight. The European Space Agency, ESA together with the French national space agency, CNES and the Japanese national space agency, NASDA are performing extensive studies using long duration bed rest.
Previous studies including several long and short term bed rest campaigns have yielded significant medical data on the physiological changes induced by space flight. These data can be used to study the effect of countermeasures, methods helping to prevent these physiological changes.
Read more
The long duration bed rest, lasting 3 months undertakes a variety of investigations involving 28 subjects. This study focuses on countermeasures, studying the effect of a bone tissue stabilisation medication and resistive exercises to determine their suitability for use during long duration stays on ISS.
The physiological changes recorded during space flight and bed rest mimic those observed in some diseases and in the aging process. Significant clinical applications are expected as a direct result of this experiment and future equivalent studies.
Read the detailed description
The spaceflights undertaken to date demonstrated that Man can adapt to the conditions existing in space, particularly to weightlessness. However, the space environment and the prevailing micro-gravity induce modifications which may affect the performances of the astronauts. These modifications concern in particular the cardiovascular and hormonal systems, the muscles, the bones, the blood and the immune system. Other problems may occur during long duration flights, such as the problems created by psychological stress due to the confinement, or those resulting from the cosmic rays (radiation).
In view of the fact that space flight opportunities are few, experiences simulating the effects of weightlessness experiences are undertaken on the earth, in order to better understand the adaptation mechanisms, prepare the spaceflights, perfect and evaluate corrective methods (called counter-measures) such as physical exercise or medication, to facilitate the astronauts' return to base. These experiments are also a necessity, in view of the difficulties encountered when carrying out certain experiences during the flights, due to the presence of too few astronauts on board, and to the lack of advanced biomedical devices onboard (scanner, etc.). The most common simulation is that of the anti-orthostatic bed rest (tilted position with the head slightly under the feet at a -6° angle).
Since the current objective is to simulate flights in the International Space Station (3 to 6 months) or possible flights to Mars (500 to 1000 days), it is mandatory to extend the duration of the simulation experiments. This is why three Space Agencies, CNES (France), European Space Agency (ESA, European Union), National Space Development Agency of Japan (NASDA, Japan) decided to join forces and undertake in common such simulation campaigns on ground, to best apprehend the adaptation processes to the constraints of the space environment.
The 2 main objectives of this experiment are:
- to study the physiological changes mechanisms during a ground-based experiment simulating long duration spaceflights,
- to develop and validate preventive methods (countermeasures) using standard tests.
This is why we will test in the present study the effects of an orthostatic bed rest (decubitus) of 90 days (3 months) on the following physiological systems :
- the bones,
- the muscles,
- the cardiovascular system and its control mechanisms,
- the sleep,
- the spine.
In the absence of gravity, the weight of the astronaut and that of the objects disappear completely. This induces modifications of the bones and the muscles which can severely affect the astronaut's life during the flight, and even more when returning to earth. This is a fundamental point to study, since it may become a limiting factor and even an obstacle to long duration flights. This experiment should also permit the test of physical exercise program and of a drug, pamidronate (AREDIA®), as counter-measures against the effects of weightlessness on the locomotion system (skeleton and muscles).
A total of 28 volunteers will participate to this experiment, split into three groups. Said experiment will spread on 2 years, 14 volunteers participating each time. The 3 groups are the following:
- Group "physical exercise" (9 volunteers),
- Group "drug" (pamidronate) (9 volunteers),
- Group "control" (10 volunteers).
Members of the groups will be drawn by lot among the participants
- Group "Exercise" : exposure of Man to microgravity results in a muscular atrophy which affects the muscles of the lumbar region and those of the lower limbs which are concerned by the standing position and the locomotion. During certain flights, physical exercise programs have been implemented, in order to fight against this muscular atrophy, maintain the physical condition required for the mission and prepare the astronauts for their return on earth. In the course of the present experiment, a physical exercise program will be tested on the 9 volunteers of this group (resistance training using both calf and knee extensor muscles with a special devicecalled Fly-Wheel).
- Group "Drug" : a Man in microgravity is the sole experimental model available to test the rapid occurrence of osteoporosis on a healthy subject. Osteoporosis, or porous bone, appears whenever the rate at which the bone material is replaced falls below that of resorption, thus creating a bone fragility and an increased risk of fracture (hip, spine and wrist essentially). It appears generally after menopause, when associated with aging and a lack of physical activity. The pamidronate (Aredia®) is a drug present on the market since many years, used for the treatment of several bone pathologies. This drug will be tested on the 9 volunteers of this group, to demonstrate its efficiency in treating of bone modifications. This drug (60mg) will be infused intravenously 14 days before bed rest.
- Group "control" : this group will serve as reference for the experimentation. Volunteers in this group will be without physical exercise and without drug. The existence of this group is necessary to be able to compare the results of the 2 types of counter-measures.
The experience will be carried out during a 120 days stay (a total of 4 months) at the Space Clinic and will comprise:
- 1 control ambulatory period of 15 days (subjects to report on day before) (-15 at -1),
- 1 anti-orthostatic (-6°) bed rest period of 90 days (1 at 90),
- 1 recovery ambulatory period of 15 days (subjects to depart the following morning) (+1 at +15), representing a total of 122 nights spent at the clinic for all volunteers.
The assessments will be done by different European and Japanese scientific teams,each one specialising in a specific domain. None of the 3 groups of volunteers will be submitted to all experimentation programs.
- Being tested
- Ethidronate, Physical training
- Keywords
- bedrest, spaceflight, Weightlessness, Countermeasure
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
EthidronateDrug
Physical trainingBehavioural
What is being measured
The primary outcome is the main question the study is designed to answer.
Muscle size and function
Muscle protein composition, muscle fiber type composition andmuscle enzyme content of soleus and vastus lateralis muscles
Bone mineral content and structure
Isokinetic muscle strength (using Cybex)
Fluid volume shift
Calcium metabolism and hormonal control
Sleep assessment by questionnaires and actigraphy
RR interval from an ECG lead signal by an high impedance probe, Systolic (SAP), Diastolic (DAP) and Mean arterial pressure (MAP) by Finapres (or Portapres) andRespiration by a piezoelectric pneumobelt,
Acetaminophen pharmacokinetic parameters,
24 h profile of spine geometry,flexibility index of spine, activity of lower back muscles,
and subjective rating of back pain
Maximal oxygen consumption.
Cardiovascular oxygen transport (oxygen delivery and oxygen return), requiring measurement of cardiac output, heart rate, arterialized blood gas composition, and arterial oxygen saturation.
Gas exchange kinetics at the onset and offset of exercise, requiring measurement of breath-by-breath ventilation and expired gas composition.
Blood volume
Plasma concentrations of arginin vasopressin, atrial natriuretic peptide, renin, endothelin, cyclic GMP and catecholamines. Urine concentrations of catecholamines, arginin vasopressin and cyclic GMP Blood concentration of nitric oxide.
Total energy expenditure, Lipid metabolism, body composition, water turnover and the formation of metabolic water.
Heart rate variability and post-ganglionic sympathetic nerve activity.
Arterial cardiac chronotropic baroreflex sensitivity and ventricular interdependence.
Ventricular mass and cardiac dimension.
Muscle architecture, including angle of pennation, fibre length, muscle thickness and muscle cross-sectional area
Energetics and biomechanics of walking and running
Parameters of vascular peripheral hemodynamics
Parameters of central hemodynamics
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Apr 2006 (estimated)
- Study startAug 2001
- Study completionJun 2003
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (11)Papers the sponsor has linked to this study.
- Other trials for Simulation of Weightlessness by Anti-Orthostatic Long Term Bed RestStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Enrolment
- 28 participants
Sponsor and investigators
- Lead sponsor
- Centre National d'Etudes Spatiales
- Sponsor type
- Other government
- Collaborators
- European Space Agency, National Space Development Agency, Japan
- Investigators
- Jacques Bernard, Dr, Principal investigator, MEDES - IMPS
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00311571
- Sponsor's protocol ID
- MEDES/00-433
- Status last verified
- Apr 2006
- First submitted
- 4 Apr 2006
- Last updated
- 4 Sep 2006
- Results posted
- No
Publications
Rittweger J, Frost HM, Schiessl H, Ohshima H, Alkner B, Tesch P, Felsenberg D. Muscle atrophy and bone loss after 90 days' bed rest and the effects of flywheel resistive exercise and pamidronate: results from the LTBR study. Bone. 2005 Jun;36(6):1019-29. doi: 10.1016/j.bone.2004.11.014. Epub 2005 Apr 2.
PubMed 15811637Watanabe Y, Ohshima H, Mizuno K, Sekiguchi C, Fukunaga M, Kohri K, Rittweger J, Felsenberg D, Matsumoto T, Nakamura T. Intravenous pamidronate prevents femoral bone loss and renal stone formation during 90-day bed rest. J Bone Miner Res. 2004 Nov;19(11):1771-8. doi: 10.1359/JBMR.040811. Epub 2004 Aug 23.
PubMed 15476576Rittweger J, Felsenberg D. Patterns of bone loss in bed-ridden healthy young male subjects: results from the Long Term Bed Rest Study in Toulouse. J Musculoskelet Neuronal Interact. 2003 Dec;3(4):290-1; discussion 292-4. No abstract available.
PubMed 15758301Gallagher P, Trappe S, Harber M, Creer A, Mazzetti S, Trappe T, Alkner B, Tesch P. Effects of 84-days of bedrest and resistance training on single muscle fibre myosin heavy chain distribution in human vastus lateralis and soleus muscles. Acta Physiol Scand. 2005 Sep;185(1):61-9. doi: 10.1111/j.1365-201X.2005.01457.x.
PubMed 16128698Rudnick J, Puttmann B, Tesch PA, Alkner B, Schoser BG, Salanova M, Kirsch K, Gunga HC, Schiffl G, Luck G, Blottner D. Differential expression of nitric oxide synthases (NOS 1-3) in human skeletal muscle following exercise countermeasure during 12 weeks of bed rest. FASEB J. 2004 Aug;18(11):1228-30. doi: 10.1096/fj.03-0792fje. Epub 2004 Jun 4.
PubMed 15180967Trappe S, Trappe T, Gallagher P, Harber M, Alkner B, Tesch P. Human single muscle fibre function with 84 day bed-rest and resistance exercise. J Physiol. 2004 Jun 1;557(Pt 2):501-13. doi: 10.1113/jphysiol.2004.062166. Epub 2004 Apr 2.
PubMed 15064323Belin de Chantemele E, Pascaud L, Custaud MA, Capri A, Louisy F, Ferretti G, Gharib C, Arbeille P. Calf venous volume during stand-test after a 90-day bed-rest study with or without exercise countermeasure. J Physiol. 2004 Dec 1;561(Pt 2):611-22. doi: 10.1113/jphysiol.2004.069468. Epub 2004 Aug 26.
PubMed 15331681Belin de Chantemele E, Blanc S, Pellet N, Duvareille M, Ferretti G, Gauquelin-Koch G, Gharib C, Custaud MA. Does resistance exercise prevent body fluid changes after a 90-day bed rest? Eur J Appl Physiol. 2004 Aug;92(4-5):555-64. doi: 10.1007/s00421-004-1121-6. Epub 2004 May 29.
PubMed 15170571Reeves NJ, Maganaris CN, Ferretti G, Narici MV. Influence of simulated microgravity on human skeletal muscle architecture and function. J Gravit Physiol. 2002 Jul;9(1):P153-4.
PubMed 15002526Perez-Diaz S, Baselet B, Lovric A, Lundberg TR, Neefs M, Daenen L, Rullman E, Fernandez-Gonzalo R. Long non-coding RNAs Kcnq1ot1 and Lncpint are involved in skeletal muscle atrophy induced by the space exposome. J Physiol. 2025 Jul;603(14):3973-3986. doi: 10.1113/JP288987. Epub 2025 Jun 29.
PubMed 40581981Belavy DL, Ohshima H, Rittweger J, Felsenberg D. High-intensity flywheel exercise and recovery of atrophy after 90 days bed--rest. BMJ Open Sport Exerc Med. 2017 Jul 24;3(1):e000196. doi: 10.1136/bmjsem-2016-000196. eCollection 2017.
PubMed 28761699
Study at a glance
From the registry record, last updated by the sponsor on 4 Sep 2006. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Simulation of a Mission Aboard the International Space Station by a Long Duration Anti-Orthostatic Bed Confinement at - 6° (90 Days) on Healthy Subjects:1/Perfecting of Preventive Methods (Muscular Exercise and Biphosphonates) and Evaluation of the Effects on the Locomotion and Cardiovascular Systems and on the Lipid and Energy Metabolisms. 2/Pharmacokinetic Assessment: Effects of Position on the Absorption Mechanisms: Pharmacokinetics of Paracetamol Used as Model to Study Oral Absorption in Simulated Weightlessness
- ClinicalTrials.gov ID
- NCT00311571
- Acronym / sponsor ID
- MEDES/00-433
- Keywords
- bedrest, spaceflight, Weightlessness, Countermeasure
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 28 participants
- Lead sponsor
- Centre National d'Etudes SpatialesOther government
- Collaborators
- European Space Agency, National Space Development Agency, Japan
- Study start
- Aug 2001
- Study completion
- Jun 2003
- First posted
- 6 Apr 2006 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Microgravity during space flight induces physiological changes that affect astronauts' health and performance. Space flight simulations such as prolonged bed rest can mimic some of these changes and provide study conditions that are more accessible than during space flight. The European Space Agency, ESA together with the French national space agency, CNES and the Japanese national space agency, NASDA are performing extensive studies using long duration bed rest.
Previous studies including several long and short term bed rest campaigns have yielded significant medical data on the physiological changes induced by space flight. These data can be used to study the effect of countermeasures, methods helping to prevent these physiological changes.
The long duration bed rest, lasting 3 months undertakes a variety of investigations involving 28 subjects. This study focuses on countermeasures, studying the effect of a bone tissue stabilisation medication and resistive exercises to determine their suitability for use during long duration stays on ISS.
The physiological changes recorded during space flight and bed rest mimic those observed in some diseases and in the aging process. Significant clinical applications are expected as a direct result of this experiment and future equivalent studies.
Detailed description
The spaceflights undertaken to date demonstrated that Man can adapt to the conditions existing in space, particularly to weightlessness. However, the space environment and the prevailing micro-gravity induce modifications which may affect the performances of the astronauts. These modifications concern in particular the cardiovascular and hormonal systems, the muscles, the bones, the blood and the immune system. Other problems may occur during long duration flights, such as the problems created by psychological stress due to the confinement, or those resulting from the cosmic rays (radiation).
In view of the fact that space flight opportunities are few, experiences simulating the effects of weightlessness experiences are undertaken on the earth, in order to better understand the adaptation mechanisms, prepare the spaceflights, perfect and evaluate corrective methods (called counter-measures) such as physical exercise or medication, to facilitate the astronauts' return to base. These experiments are also a necessity, in view of the difficulties encountered when carrying out certain experiences during the flights, due to the presence of too few astronauts on board, and to the lack of advanced biomedical devices onboard (scanner, etc.). The most common simulation is that of the anti-orthostatic bed rest (tilted position with the head slightly under the feet at a -6° angle).
Since the current objective is to simulate flights in the International Space Station (3 to 6 months) or possible flights to Mars (500 to 1000 days), it is mandatory to extend the duration of the simulation experiments. This is why three Space Agencies, CNES (France), European Space Agency (ESA, European Union), National Space Development Agency of Japan (NASDA, Japan) decided to join forces and undertake in common such simulation campaigns on ground, to best apprehend the adaptation processes to the constraints of the space environment.
The 2 main objectives of this experiment are:
- to study the physiological changes mechanisms during a ground-based experiment simulating long duration spaceflights,
- to develop and validate preventive methods (countermeasures) using standard tests.
This is why we will test in the present study the effects of an orthostatic bed rest (decubitus) of 90 days (3 months) on the following physiological systems :
- the bones,
- the muscles,
- the cardiovascular system and its control mechanisms,
- the sleep,
- the spine.
In the absence of gravity, the weight of the astronaut and that of the objects disappear completely. This induces modifications of the bones and the muscles which can severely affect the astronaut's life during the flight, and even more when returning to earth. This is a fundamental point to study, since it may become a limiting factor and even an obstacle to long duration flights. This experiment should also permit the test of physical exercise program and of a drug, pamidronate (AREDIA®), as counter-measures against the effects of weightlessness on the locomotion system (skeleton and muscles).
A total of 28 volunteers will participate to this experiment, split into three groups. Said experiment will spread on 2 years, 14 volunteers participating each time. The 3 groups are the following:
- Group "physical exercise" (9 volunteers),
- Group "drug" (pamidronate) (9 volunteers),
- Group "control" (10 volunteers).
Members of the groups will be drawn by lot among the participants
- Group "Exercise" : exposure of Man to microgravity results in a muscular atrophy which affects the muscles of the lumbar region and those of the lower limbs which are concerned by the standing position and the locomotion. During certain flights, physical exercise programs have been implemented, in order to fight against this muscular atrophy, maintain the physical condition required for the mission and prepare the astronauts for their return on earth. In the course of the present experiment, a physical exercise program will be tested on the 9 volunteers of this group (resistance training using both calf and knee extensor muscles with a special devicecalled Fly-Wheel).
- Group "Drug" : a Man in microgravity is the sole experimental model available to test the rapid occurrence of osteoporosis on a healthy subject. Osteoporosis, or porous bone, appears whenever the rate at which the bone material is replaced falls below that of resorption, thus creating a bone fragility and an increased risk of fracture (hip, spine and wrist essentially). It appears generally after menopause, when associated with aging and a lack of physical activity. The pamidronate (Aredia®) is a drug present on the market since many years, used for the treatment of several bone pathologies. This drug will be tested on the 9 volunteers of this group, to demonstrate its efficiency in treating of bone modifications. This drug (60mg) will be infused intravenously 14 days before bed rest.
- Group "control" : this group will serve as reference for the experimentation. Volunteers in this group will be without physical exercise and without drug. The existence of this group is necessary to be able to compare the results of the 2 types of counter-measures.
The experience will be carried out during a 120 days stay (a total of 4 months) at the Space Clinic and will comprise:
- 1 control ambulatory period of 15 days (subjects to report on day before) (-15 at -1),
- 1 anti-orthostatic (-6°) bed rest period of 90 days (1 at 90),
- 1 recovery ambulatory period of 15 days (subjects to depart the following morning) (+1 at +15), representing a total of 122 nights spent at the clinic for all volunteers.
The assessments will be done by different European and Japanese scientific teams,each one specialising in a specific domain. None of the 3 groups of volunteers will be submitted to all experimentation programs.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
Who may qualify
- Ages
- 25 to 45 years
- Sex
- Male only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (9 listed)
- Healthy male volunteer , citizen of the European Community.
- Age 25 to 45,
- Non smokers,
- No alcohol, no drug dependence and no medical treatment,
- Height 165 cm to 185 cm,
Key exclusion criteria (14 listed)
- Having given blood (more than 300ml) in a period of three months or less before the start of the experiment,
- Subject already participating in a clinical research experimentation,
- Poor tolerance to blood sampling,
- Past record of orthostatic intolerance,
- Cardiac rhythm disorders,
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Ethidronate | Drug | – |
| Physical training | Behavioural | – |
Primary outcome
Muscle size and function
Muscle protein composition, muscle fiber type composition andmuscle enzyme content of soleus and vastus lateralis muscles
Bone mineral content and structure
Isokinetic muscle strength (using Cybex)
Fluid volume shift
Calcium metabolism and hormonal control
Sleep assessment by questionnaires and actigraphy
RR interval from an ECG lead signal by an high impedance probe, Systolic (SAP), Diastolic (DAP) and Mean arterial pressure (MAP) by Finapres (or Portapres) andRespiration by a piezoelectric pneumobelt,
Acetaminophen pharmacokinetic parameters,
24 h profile of spine geometry,flexibility index of spine, activity of lower back muscles,
and subjective rating of back pain
Maximal oxygen consumption.
Cardiovascular oxygen transport (oxygen delivery and oxygen return), requiring measurement of cardiac output, heart rate, arterialized blood gas composition, and arterial oxygen saturation.
Gas exchange kinetics at the onset and offset of exercise, requiring measurement of breath-by-breath ventilation and expired gas composition.
Blood volume
Plasma concentrations of arginin vasopressin, atrial natriuretic peptide, renin, endothelin, cyclic GMP and catecholamines. Urine concentrations of catecholamines, arginin vasopressin and cyclic GMP Blood concentration of nitric oxide.
Total energy expenditure, Lipid metabolism, body composition, water turnover and the formation of metabolic water.
Heart rate variability and post-ganglionic sympathetic nerve activity.
Arterial cardiac chronotropic baroreflex sensitivity and ventricular interdependence.
Ventricular mass and cardiac dimension.
Muscle architecture, including angle of pennation, fibre length, muscle thickness and muscle cross-sectional area
Energetics and biomechanics of walking and running
Parameters of vascular peripheral hemodynamics
Parameters of central hemodynamics
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Sep 2006.
- Results publication: PubMed 15811637Rittweger J, Frost HM, Schiessl H, Ohshima H, Alkner B, Tesch P, Felsenberg D. Muscle atrophy and bone loss after 90 days' bed rest and the effects of flywheel resistive exercise and pamidronate: results from the LTBR study. Bone. 2005 Jun;36(6):1019-29. doi: 10.1016/j.bone.2004.11.014. Epub 2005 Apr 2.
- Results publication: PubMed 15476576Watanabe Y, Ohshima H, Mizuno K, Sekiguchi C, Fukunaga M, Kohri K, Rittweger J, Felsenberg D, Matsumoto T, Nakamura T. Intravenous pamidronate prevents femoral bone loss and renal stone formation during 90-day bed rest. J Bone Miner Res. 2004 Nov;19(11):1771-8. doi: 10.1359/JBMR.040811. Epub 2004 Aug 23.
- Results publication: PubMed 15758301Rittweger J, Felsenberg D. Patterns of bone loss in bed-ridden healthy young male subjects: results from the Long Term Bed Rest Study in Toulouse. J Musculoskelet Neuronal Interact. 2003 Dec;3(4):290-1; discussion 292-4. No abstract available.
- Results publication: PubMed 16128698Gallagher P, Trappe S, Harber M, Creer A, Mazzetti S, Trappe T, Alkner B, Tesch P. Effects of 84-days of bedrest and resistance training on single muscle fibre myosin heavy chain distribution in human vastus lateralis and soleus muscles. Acta Physiol Scand. 2005 Sep;185(1):61-9. doi: 10.1111/j.1365-201X.2005.01457.x.
- Results publication: PubMed 15180967Rudnick J, Puttmann B, Tesch PA, Alkner B, Schoser BG, Salanova M, Kirsch K, Gunga HC, Schiffl G, Luck G, Blottner D. Differential expression of nitric oxide synthases (NOS 1-3) in human skeletal muscle following exercise countermeasure during 12 weeks of bed rest. FASEB J. 2004 Aug;18(11):1228-30. doi: 10.1096/fj.03-0792fje. Epub 2004 Jun 4.
- Results publication: PubMed 15064323Trappe S, Trappe T, Gallagher P, Harber M, Alkner B, Tesch P. Human single muscle fibre function with 84 day bed-rest and resistance exercise. J Physiol. 2004 Jun 1;557(Pt 2):501-13. doi: 10.1113/jphysiol.2004.062166. Epub 2004 Apr 2.
- Results publication: PubMed 15331681Belin de Chantemele E, Pascaud L, Custaud MA, Capri A, Louisy F, Ferretti G, Gharib C, Arbeille P. Calf venous volume during stand-test after a 90-day bed-rest study with or without exercise countermeasure. J Physiol. 2004 Dec 1;561(Pt 2):611-22. doi: 10.1113/jphysiol.2004.069468. Epub 2004 Aug 26.
- Results publication: PubMed 15170571Belin de Chantemele E, Blanc S, Pellet N, Duvareille M, Ferretti G, Gauquelin-Koch G, Gharib C, Custaud MA. Does resistance exercise prevent body fluid changes after a 90-day bed rest? Eur J Appl Physiol. 2004 Aug;92(4-5):555-64. doi: 10.1007/s00421-004-1121-6. Epub 2004 May 29.
- Results publication: PubMed 15002526Reeves NJ, Maganaris CN, Ferretti G, Narici MV. Influence of simulated microgravity on human skeletal muscle architecture and function. J Gravit Physiol. 2002 Jul;9(1):P153-4.
- Derived from this study: PubMed 40581981Perez-Diaz S, Baselet B, Lovric A, Lundberg TR, Neefs M, Daenen L, Rullman E, Fernandez-Gonzalo R. Long non-coding RNAs Kcnq1ot1 and Lncpint are involved in skeletal muscle atrophy induced by the space exposome. J Physiol. 2025 Jul;603(14):3973-3986. doi: 10.1113/JP288987. Epub 2025 Jun 29.
- Derived from this study: PubMed 28761699Belavy DL, Ohshima H, Rittweger J, Felsenberg D. High-intensity flywheel exercise and recovery of atrophy after 90 days bed--rest. BMJ Open Sport Exerc Med. 2017 Jul 24;3(1):e000196. doi: 10.1136/bmjsem-2016-000196. eCollection 2017.
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Jacques Bernard, Dr principal investigator
MEDES - IMPS
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Ethidronate and Physical training in people with Simulation of Weightlessness by Anti-Orthostatic Long Term Bed Rest, run by Centre National d'Etudes Spatiales at 1 site in France.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 9 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 4 Sep 2006. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in France. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Muscle size and function. The study lists 24 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00311571, which also lists 11 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 4 Sep 2006.