A trip to space is no fun for your body. In fact, even extremely fit astronauts have weakened bones long after return. But if you do your best with strength training on board, it will suffer less.

Many astronauts who have been in space for a longer period of time still have weaker bones a year after returning to Earth. This is apparent from a small study of seventeen international astronauts (fourteen men and three women), published in Scientific Reports† It has long been clear that muscles and bones are affected by the continuous state of weightlessness during space travel. That is why it is not recommended to stay in space for a long time. To limit the damage somewhat, astronauts do physical exercises every day, so that their physical condition remains as high as possible.

Pump it up

From research by the University of Calgary in Canada it appears that more resistance exercises during space travel can indeed help against brittle bones. The average bone density of the tibia in the year after space travel was higher in the astronauts who had done relatively more strength training on board.

In all subjects, the shinbone (tibia) and radius (radius) in the forearm were tested for thickness, presence of minerals and bone strength (maximum load). Eight astronauts were outside the atmosphere for less than six months. Nine subjects were part of a longer-term mission.

The bones of the fourteen men and three women were tested on four occasions: just before the flight, just after the flight, six months later, and finally twelve months after their return to Earth. The astronauts’ training regimen was also tracked. The length and intensity of stationary bike cycling, treadmill running and deadlifting (lifting heavy weights from the floor to waist height) were also included in the study.

ISS Space Station, Photo: NASA

shinbone
No signs of weakening were found in the radius bones one year after space travel. The shin bones, however, were considerably weakened after the mission. Even after twelve months, the shin bone values ​​of sixteen of the seventeen subjects were still lower.

The average strength of the tibia was one year later one and a half percent lower. There was a reduction from 152 newtons to 10,427 newtons. This is a kilogram pressure of about 1063 kgf. The bone density was on average 4.5 milligrams lower per cubic centimeter, compared to the 326.8 mg/cm3 measured before the flight. That is also a reduction of about one and a half percent.

Ten years older
Team leader Steven Boyd and his colleagues concluded that the average bone damage is greater in the astronauts who spent longer in space. One year after their return, this group still had more than three percent weaker shin bones. The same was true for bone density.

This degree of damage to the lower leg can be compared with the bone reduction of an adult in ten years of life. Bone aging is therefore extremely fast in the ISS space station: in six months your bones can age ten years.

The path of most resistance
Astronauts who had been fanatical about deadlifts aboard the space station compared to their training routine on Earth were in the best shape after the mission. The authors of the scientific research therefore recommend that you continue to train vigorously on board.

In addition to the above exercises, they also propose a resistance exercise with a jump, with a lot of impact on the lower legs. This exercise can ensure that the shin bones remain in good condition during and after a long space journey.

Even in orbit around the earth you cannot escape the fitness trainer and his merciless training schedules. It is unfortunately the path of most resistance.