Most of the workshops require you to be able to walk with your gear to a shooting location. These are rarely strenuous, but can be a half of a mile or more. I don’t think there are any longer than a mile.
There are some with very little exertion like the Kenya Photo Safari.
Either my partner or I have photographed at all of the workshop locations so I can give you more specifics and advice. Get in touch with me and can give you the scoop on the difficulty level of any workshop that interests you.