Staying strong in orbit with ARED

Exercise is one of the most important countermeasures against the effects of spaceflight. Without Earth’s constant gravitational pull, astronauts experience losses in bone density, muscle mass and cardiovascular fitness. Even though these changes are temporary, they can affect an astronaut’s well-being, performance, and overall safety in orbit.   

To help maintain their health, astronauts train daily on specialised exercise equipment on board the International Space Station: the T2 treadmill, the CEVIS bike, and the Advanced Resistive Exercise Device (ARED), which simulates weightlifting in space.  

ARED Kinematics, an experiment from Politecnico di Milano, developed by Kayser Italia and supported by ESA, aims to answer key questions about exercising on ARED, including how resistance exercise affects joint loading and muscle activation. Understanding these is crucial for maintaining muscle strength and protecting bone health in microgravity. 

At the start of each ARED Kinematics session, astronauts perform a strength calibration test to tailor exercise loads to their capability. They then complete a series of exercises, including standard squats, single-leg squats, wide-stance squats and deadlift pulls, using different resistance levels to assess how load influences performance. 

Researchers will compare data collected before flight with measurements taken in orbit and again about a week after splashdown. This will allow them to study how movement patterns differ between exercise on Earth and in microgravity. It will also help quantify how performance adapts over time and determine the extent and duration of functional recovery after a long exposure to microgravity. 

“As I love sport, it makes me really happy to be working on several experiments focused on physical exercise during the εpsilon mission! Unexpected bonus: it is supported by the French User Support Operations Centre (CNES/CADMOS), and as the sessions are conducted in private, it feels really good to switch back to my native French while working!” explains ESA astronaut Sophie Adenot after her third on-orbit session.  

The results from ARED Kinematics will help scientists refine existing exercise countermeasures and support astronaut health and performance on future long‑duration missions.