Here’s an idea for a persistence of vision jumprope which displays cycles, time, or calories burned.
It’s only a design concept at this point, but I’m sure some knowledgeable maker out there can beat it to the punch. Hmm, I wonder if the (somewhat) variable curvature of the rope would present a legibility problem – perhaps necessitating a wider display area? – POV jumprope [Thanks, goodEvans!]
Binary POV wristwatch
In the Maker store: