Posted on 11 March 2011 at 14:02h

I was staying at a hotel the other week and thought I'd pay the gym a visit.  usually just train upper body strength since that's what I need for rock climbing however the Gym didn't have any of the usual apparatus just a couple of treadmills so I thought I'd give one a go. I've never been on one before so didn't know that you were supposed to switch it on, as a result the first 5 minutes were very difficult as I tried to push the belt round with my legs (good training though). As I was pushing away I tried pressing all of the buttons and must have got the right one as the belt sprang into life and started moving on its own. It's amazing how easy it seems when not only is all resistance removed but the belt actually moves on its own. After another 10 minutes I got a bit bored moving my legs back and forth so begun to crank up the speed and also found out that you can change the angle. I'm not used to running but found it quite easy running uphill on the machine so got thinking about the physics involved. Where is all the energy going? I wasn't actually going uphill so wasn't increasing my PE, not getting any faster so no KE and there wasn't any friction (not since  I switched it on at least) so no work against friction, the only thing  I was doing was moving my legs. People who use these machines tell me that when you run uphill it is more difficult and you use more energy but why? A better version would be one where you run up the hill then the belt comes on and whisks you to the bottom again ready for a repeat performance, probably wouldn't work as a treadmill but there is a climbing wall version and I think this principle could actually be used.