Was the word 'sprint' chosen to describe a never ending crunch? Or just to roughly imply quick forward motion. Unlike waterfall that often slows for large porti

Was the word 'sprint' chosen to describe a never ending crunch? Or just to roughly imply quick forward motion. Unlike waterfall that often slows for large portions of time until the next sudden and irreversible release? Perhaps it would've been more accurate to use something like 'unit' in education. Which is just a subdivision of time and effort roughly equal to a week or two.