According to a Western researcher, a little more time on the treadmill may be just what the doctor ordered for Canada's astronauts battling microgravity's effects on circulation. Kevin Shoemaker, Associate Dean of Research in the Faculty of Health Sciences, said his group's new findings can improve astronauts' health and may also help understand and prevent falls among frail elderly people on Earth.

Shoemaker was co-investigator on the Cardiovascular and Cerebrovascular Control on Return from the International Space Station (CCISS), which studied the effects of long space missions on astronauts' hearts and the blood vessels that supply the brain. Lack of gravity can disrupt astronauts' blood circulation, giving them puffy faces and 'bird legs as blood moves from the lower body and congests in the head and chest.

When astronauts return to Earth, the distribution reverses. Blood collects in their lower body and, if not enough oxygen-rich blood reaches the brain, some astronauts could experience dizziness, fainting or blurred vision. Astronauts' hearts are affected by the lack of gravity when they arrive in space and by reintroduction to gravity when they return to Earth, Shoemaker said.

"They can be up there for six to 12 months. The analog version of that on Earth is if we put someone in bed; you still use your arms, you eat, you read. Our strength doesn't change, but our legs just shrivel. The point is, it's a rather severe version of physical inactivity – bed rest or space flight."

The study's aim was to gain a better understanding of how astronauts' cardiovascular systems adapt to conditions aboard the International Space Station and how to maintain astronauts' health once they return to Earth. Six astronauts took part in this study by wearing devices that measured blood pressure, heart rate and physical activity pattern during waking hours and sleep before, during and after their space missions.

Shoemaker found heart rate response and changes in blood pressure differed significantly among astronauts. These results could point to a need for some crew members to exercise more or take other steps to help protect their blood pressure response on return to Earth. "The fact is, when we have to work against gravity all the time, and you get this downward pull on things, our bone strength depends upon it being loaded.

Author hopes to generate more complete imaging of the astronauts while they are on the Space Station, determining when changes to the body are occurring and to what extent, using a robotic ultrasound system for remote monitoring. In between exercise lessons learned from space have practical implications on Earth.

Author concludes that there is this relationship between the amount of physical activity we get and our general health. Bone, glucose metabolism, muscle health, brain health these depend on some form of physical activity. This links some fundamental level of physical activity, which is easier to get on Earth than in space.