Around the bed in 60 days

Around the bed in 60 days
by Staff Writers
Paris (ESA) May 24, 2023

Lying in bed for a full 60 days - with one shoulder always touching the mattress - might sound like bliss, but add cycling, spinning and constant medical tests to the equation and it becomes a challenging experience for the sake of human space exploration.

A group of 12 volunteers are bracing themselves for a bedridden journey that put them into a compulsory reclined lifestyle. Participants are kept in beds tilted 6 below the horizontal with their feet up - meals, showers and toilet breaks included.

As blood flows to the head and muscle is lost from underuse, researchers are charting how their bodies react. Bedrest studies offer a way of testing measures to counter some of the negative aspects of living in space.

During space missions, astronauts' bodies go through a wide array of changes due to lack of gravity - everything from their eyes to their heart is affected, and muscles and bones start to waste away.

Cycle and centrifuge rides
The BRACE (Bed Rest with Artificial gravity and Cycling Exercise) study investigates how cycling could counteract the changes the human body experiences in space.

The bikes are adapted to be used in bed and on a centrifuge device to mimic artificial gravity. Volunteers are spun to drive blood towards their feet, where the force of gravity doubles during the ride. The intensity of the centrifugal force is adapted to each person according to their tolerance to hypergravity.

"We encourage volunteers to reach their maximum effort on the bike, and then compare the impact with those who are not biking at all," explains Rebecca Billette, head of clinical research at MEDES, the Institute for Space Medicine and Physiology in Toulouse, France.

Researchers will compare cycling in bed and cycling as the volunteers are spun on a centrifuge and a third control group that stays in bed for the full two months with no exercise bike or centrifuge rides. "We will compare the impact of a daily exercise routine on a variety of physiological factors," adds Rebecca.

This is the first time cycling is part of a bedrest study in Europe.

"We hope to understand the added value of artificial gravity to the fitness routine astronauts follow on the International Space Station. The crew exercise two hours per day in orbit," says Angelique Van Ombergen, ESA lead for life sciences at Human and Robotic Exploration.

Artificial gravity is promising because it acts on all human organs at once. "It could become an effective solution for a healthier body during long-duration space missions, if the technological challenges can be overcome," adds Angelique.

Space for medicine
Astronauts face similar physiological problems as elderly and bedridden patients on Earth. Long stays in orbit affect their muscles and bones.

"Results from space analogues can be useful to design better treatments for the elderly and for patients with musculoskeletal conditions and osteoporosis on Earth," says Angelique.

ESA regularly organises bedrest studies of varying lengths, with both men and women, since 2001.

This study is supported by the French Space Agency CNES. BRACE is built on a previous study that ESA ran with the US and German space agencies in 2019 with a focus on artificial gravity at the German aerospace centre DLR's ':envihab' facility in Cologne, Germany.

The next stop for a simulated space ride with other 12 volunteers will be in Slovenia at the Jozef Stefan Institute.

Researchers will conduct a new round of 60-day studies combining vibration exercise and artificial gravity.