That is impressive.
I know people with stand up electric wood lathes who don't make things as nice as that guy did with a bow drive lathe while using his foot to guide the chisel.
There used to be a TV show called the wood right shop with Roy Underhill as the host. He only uses human powered tools. He had a similar bow lathe. His lathe was driven with a foot pedal on the bottom of the bow and a spring on the top of the bow that was suspended from the ceiling. This freed up both hands to guide the chisel.
Last year I saw an antique pedal powered machine lathe. There are a lot of hobby machinists, including myself, that should get one to get in shape.
Chris