The idea, is that you set up the activities so that they won't distress. Like learning to swim is daunting for everybody. However for somebody who can't see and will be relying on other senses, it would be more daunting with a lot of other people around - this could cause distress.
A "labor of distress" is not always easily recognised however in the case of the "Activity Ideas for the visually impaired" forward thinking and planning would prevent most of these depending on the person.
We don't usually set out to learn something that distresses us, however many times we are faced with a labour of distress.
Thanks for asking a question, if I haven't answered your question feel free to ask again! :)