Exercise in space: the European Space Agency approach to in-flight exercise countermeasures for long-duration missions on ISS

Abstract

BackgroundTo 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.ResultsWith 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.ConclusionIncreased 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.

Exercise as a countermeasure for latent viral reactivation during long duration space flight

“…However, not all exercise performance data (eg, heart rate, workloads, etc) were recorded on the ISS leaving the possibility that the groups with different levels of CRF deconditioning exercised at different workloads. A previous study reported that astronauts may train at lower intensities due to discomfort with current exercise equipment onboard the ISS, while mission to mission variation in the amount of scheduled time for exercise could also have been a factor. Regardless, some of our crewmembers were able to maintain high levels of CRF throughout the mission, indicating that highly tailored exercise programs will be effective in maintaining CRF conditioning during long duration space travel that might, in turn, protect against latent viral reactivation.…”

Muscle unloading: A comparison between spaceflight and ground‐based models

“…For example, the training regimes used by the United States operating segments (NASA, Canadian & European Space Agencies and Japan Aerospace Exploration Agency) involve advanced trainings for resistance (Advanced Resistive Exercise Device; ARED) 225 and endurance (Cycle Ergometer with Vibration, Isolation and Stabilization; CEVIS & second generation treadmill; T2) exercises. 226 On the other hand, Russian operating segment use modified treadmill and cycle ergometer equipped with a force loader (HC)-1 for endurance and resistance exercises. This equipment is complemented with compression thigh cuffs, suits for lower body compression and axial loading and negative pressure trousers.…”

Ergonomic Challenges for Astronauts during Space Travel and the Need for Space Medicine

“…This allows mission planners to propose and agree mitigation risks, some of which will include the development and refinement of countermeasures. There are many reviews which summarise the potential and actual countermeasures which are in put in place and a representative set is cited for further interest [2, 7,10,34,50,53,57,71,72,74,[76][77][78][79][80][81]. In Table 2, countermeasures in operation today are described for each of the physiological and psychological effects of spaceflight described in the preceding sections.…”

“…vertical treadmills, nutrition and pharmacological regimes. Development of tools to predict muscle and bone loss [76,78,79] Healing capacity Risk-based monitoring to reduce injury, pharmacological intervention [7,77] Limited data available on healing rates in humans in space. Translation of animal model to human healing rates in microgravity requires further exploration N/A Evaluation of medications used in-flight in 79 space shuttle missions showed that the majority of medications provided for and taken were for motion sickness, sleep disturbance and as analgesics or anticongestants [100].…”