Canadian astronaut Bob Thirsk exercises with a harness aboard the International Space Station during ISS Expedition 20/21. ((NASA))

Hitting the gym helps slow the aging process in space, as well as on Earth, Canadian scientists have found.

Normally, spending six months on the International Space Station can be like taking a trip on an accelerated aging device that makes astronauts as weak as 80-year-olds.

Researchers discovered that in the weightless environment of space, without exercise:

  • Muscle-power decline in 40-year-old astronauts is equivalent to that of a person twice as old.
  • Astronauts lose more than 40 per cent of the slow-twitch fibres in their calf muscles, which are important for balance and posture.
  • Up to two per cent of bone mineral density is lost each month — four times the rate for a post-menopausal women on Earth.

Canadian astronauts contributed data for a seven-year study by Prof. Richard Hughson, research chair in vascular aging and brain health at the University of Waterloo.

Hughson describes his research to the CBC's Kelly Crowe.