Hi Les,
I did this tour last year with Travelsphere and I would say a good pair of trainers would be adequate. There is very little rough ground to walk on. The last thing you want is to pack is something you don’t really need!
This tour has some early starts but they are worth it as the experience of seeing the magnificent sights of the National Parks will live in your memory for many a year.
Take plenty of memory cards for your cameras as you will take lots of photos both still and movie. Favourite for me was Bryce Canyon NP, Monument Valley, Arches NP and the Lake Powell boat ride. But having said that, every day is awe-inspiring as they say.
Have a great tour.
Malcolm