A Cautionary Tale...

When demonstrating turning on the leg-powered lathe the most frequently asked question is "Don't you get one big muscley leg from doing that all day" to which the joke reply is "Yes, but I live on the side of a steep mountain and walk round in circles on the flat!".  Then I get more serious and explain that I balance it out by changing legs often.
Someone at a show told me they'd watched me for about an hour then come back later and I was still treadling with the same leg.  I started to watch myself after that and realised that my default position was to stand on my right leg and treadle with the left.  No matter how often I caught myself doing this and made a conscious effort to change I would still return to that position.  So left leg gets plenty exercise and right leg bears all the weight.
My doctor asked what I did for a living and when I told him he explained that this posture had undoubtedly led to my prolapsed disc, sciatica in the right leg and excruciating agony all Winter and most of the Spring.
So take heed you pole lathe turners and change legs often!