We’ve all seen astronauts (and cosmonauts) floating around in the International Space Station. Older readers will remember them floating around in the back of the space shuttle. To make the obvious point, the reason for this is that there’s a massive reduction in gravity once we (OK, so we’re all astronauts now) leave the Earth’s atmosphere. With this reduction of gravity, we humans experience a real problem to our physiques. This includes bone and muscle loss, and the only real way to counteract this is to carry out several hours of activities each day.
The Space Station’s gym comprises three machines designed to give us gravity-lubbers a full-body workout; a bicycle, a treadmill, and a weightlifting machine, or Advanced Resistive Exercise Device to give it it’s technical name. All three machines are specifically designed for space, as normal gym equipment would be useless in microgravity. The act of lifting a weight, for example, isn’t feasible in space since weight is a purely gravitational concept. The ARED machine counteracts this by using vacuum resistance, a little like hydraulics. In order to run in microgravity, the astronauts are strapped into the treadmill with harness and bungee cords to prevent them from floating away. Astronauts grip the bicycle’s handles and sit up against a back pad so that they can further strengthen their legs. There’s no seat because there’s no need to sit down if you’re floating by default! It must all take some getting used to though, don’t you think?