Look here for an explanation of the Inquisition. Inquisition - Wikipedia, the free encyclopedia. During that time, various methods of torture were used to extract confessions from people. One of these was the rack, a machine to which a person was strapped and had his body mercilessly stretched.
A jazzy exercise could be one in which the exercise is accompanied by jazz music.
In a contorted workout, the body is twisted into unusual positions. The writer is equating this to torture.
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