Cost-effective countermeasures to maintain muscle mass, muscle strength, and physical performance during muscle wasting and ageing 

There is little data on how human muscles react to long periods of disuse – and even less on gender differences. Results from bedrest studies are helping design countermeasures to prevent muscle deconditioning of aged, diseased or disabled people. The Women’s International Space Simulation for Exploration, known as the WISE study was the first long-duration bedrest programme conducted in Europe using female subjects. For 60 days in a row, 24 volunteers did not leave their hospital bed. The researchers paid attention to the effects of long-term bed rest on arm and leg muscles. Around 60 women have flown in space, representing 10% of all astronauts. “We needed the women, the time and the clinical environment to evaluate our countermeasures. ESA gave us a great opportunity to simulate space on Earth,” says Angèle Chopard. The WISE study increased our knowledge of gender differences during simulated weightlessness. The women experienced up to 25% muscle atrophy while gene expression changed all the volunteers’ muscle. The larger muscle volume in men compared with women appears to be one of the most important factors enhancing the degree of atrophy. The study allowed researchers to test exercise and nutritional programmes to counteract the negative effects of living in space, especially for future missions to the Moon or Mars.