title: Exercise in space: the European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS.
abstract: BACKGROUND
  To counteract microgravity (µG)-induced adaptation, European Space Agency (ESA) astronauts on long-duration missions (LDMs) to the International Space Station (ISS) perform a daily physical exercise countermeasure program. Since the first ESA crewmember completed an LDM in 2006, the ESA countermeasure program has strived to provide efficient protection against decreases in body mass, muscle strength, bone mass, and aerobic capacity within the operational constraints of the ISS environment and the changing availability of on-board exercise devices. The purpose of this paper is to provide a description of ESA's individualised approach to in-flight exercise countermeasures and an up-to-date picture of how exercise is used to counteract physiological changes resulting from µG-induced adaptation. Changes in the absolute workload for resistive exercise, treadmill running and cycle ergometry throughout ESA's eight LDMs are also presented, and aspects of pre-flight physical preparation and post-flight reconditioning outlined.
  
  
  RESULTS
  With the introduction of the advanced resistive exercise device (ARED) in 2009, the relative contribution of resistance exercise to total in-flight exercise increased (33-46 %), whilst treadmill running (42-33 %) and cycle ergometry (26-20 %) decreased. All eight ESA crewmembers increased their in-flight absolute workload during their LDMs for resistance exercise and treadmill running (running speed and vertical loading through the harness), while cycle ergometer workload was unchanged across missions.
  
  
  CONCLUSIONS
  Increased or unchanged absolute exercise workloads in-flight would appear contradictory to typical post-flight reductions in muscle mass and strength, and cardiovascular capacity following LDMs. However, increased absolute in-flight workloads are not directly linked to changes in exercise capacity as they likely also reflect the planned, conservative loading early in the mission to allow adaption to µG exercise, including personal comfort issues with novel exercise hardware (e.g. the treadmill harness). Inconsistency in hardware and individualised support concepts across time limit the comparability of results from different crewmembers, and questions regarding the difference between cycling and running in µG versus identical exercise here on Earth, and other factors that might influence in-flight exercise performance, still require further investigation.
authors.affiliation: Wyle GmbH, Cologne, Germany ; Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany ; Institute of Training Science and Sport Informatics, German Sport University Cologne (DSHS), Am Sportpark Muengersdorf 6, 50933 Cologne, Germany.
authors.forename: Nora
authors.identifier: 0000-0003-0239-9038
authors.initials: N
authors.lastname: Petersen
authors.affiliation: Wyle GmbH, Cologne, Germany ; Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany.
authors.forename: Patrick
authors.initials: P
authors.lastname: Jaekel
authors.affiliation: Wyle GmbH, Cologne, Germany ; Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Rosenberger
authors.affiliation: Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany.
authors.forename: Tobias
authors.initials: T
authors.lastname: Weber
authors.affiliation: Wyle GmbH, Cologne, Germany ; Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Scott
authors.affiliation: Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany ; Deutsches Zentrum fuer Luft-und Raumfahrt, Cologne, Germany.
authors.forename: Filippo
authors.initials: F
authors.lastname: Castrucci
authors.affiliation: Wyle GmbH, Cologne, Germany.
authors.forename: Gunda
authors.initials: G
authors.lastname: Lambrecht
authors.affiliation: Universities Space Research Association, NASA Johnson Space Center, B261, SK3, Houston, TX 77058 USA.
authors.forename: Lori
authors.initials: L
authors.lastname: Ploutz-Snyder
authors.affiliation: Space Medicine Office (HSO-AM), European Astronaut Centre Department, Directorate of Human Spaceflight and Operations (D/HSO), European Space Agency (ESA), Geb. 12, Linder Höhe, PO Box 906096, 51147 Cologne, Germany ; International Space University (ISU), Parc d'Innovation, 1 Rue Jean-Dominique Cassini, 67400 Illkirch-Graffenstaden, France.
authors.forename: Volker
authors.initials: V
authors.lastname: Damann
authors.affiliation: Institute for Biomedical Problems (IBMP), Russian Space Federation/Roscosmos, Khoroshevskoe Shosse, 76A, 123007 Moscow, Russia.
authors.forename: Inessa
authors.initials: I
authors.lastname: Kozlovskaya
authors.affiliation: Institute of Training Science and Sport Informatics, German Sport University Cologne (DSHS), Am Sportpark Muengersdorf 6, 50933 Cologne, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Mester
keywords: Astronaut training; European Space Agency; Exercise countermeasures; International Space Station; Microgravity; Physical performance; Space flight