What exactly was the purpose of those jiggle-belt gym machines circa pre-1960s?

What about “steam cabinets”? They looked like washing machines-you sat inside, with a hole for your head to stick out. What were these intended to do to you?

Quote:
it uses the infrared ray given off by the over-ma-gnetic wave to permeate to the subcutaneous tissue of the body fat, it can make the fat motion directly and pass through the muscles and skin to 4-7cm deep,8 different frequency vibrations worked directly on your skin with 5 high frequency vibrators.and the particulate grease will be burned out by 8:100 over-powerful magnetic wave in continuous usage.
I wonder if that would violate the rules about not cooking anything smelly at the office.

Sorry for resurrecting this old thread, but I’d like to know what these machines were actually called. Is there maybe a Wikipedia article or some other reference which gives a general overview of their history and use?

I dug up a page from the Kansas Historical Society that describes them as “belt exercisers”, “belt vibrators”, and “vibrating exercisers”. There may not be a standardized name.