Vitruvian Man...first exercise manual?

It's interesting how perceptions of art are filtered through each one's subjective, historical experiences, and perspectives. This is especially troublesome when the artist leaves little or no information behind to explain or otherwise aid our understanding of the work, e.g. cave paintings or Damien Hirst.

I thought about this the other day when reading about da Vinci's "Vitruvian Man" drawing. Paraphrased from Encyclopaedia Britannica via Wikipedia , "Leonardo (can I call you Leonardo?) envisaged the great picture chart of the human body he had produced through his anatomical drawings and Vitruvian Man as a cosmografia del minor mondo (cosmography of the microcosm). He believed the workings of the human body to be an analogy for the workings of the universe."

Okay that sounds all well and good if you're an academic with letters after your name, but what struck me as I looked at it, considering it closely as if for the first time was, "are you sure he's not just explaining how to do a "jumping-jack?"