The concession made by the author is that fitness machines bores people.
The tone of the paragraph is an informal one.
This refers to the figure of speech that has to do with the use of a statement that looks contradictory but contains elements of truth in them.
Hence, we can see that a sentence that contains a rhetorical question is, "Does anybody want to die?". Also, a paradox that was used by the author is that people should exercise, without the use of silly machines.
Read more about paradoxes here:
https://brainly.com/question/17731343
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