cycling, swimming and legs
I was a cycling racer and shaved legs. Its not for any speed advantage...but if you crash it is much easier to clean and bandage. Alos much neater for that post race leg massage.
My sons swam (one still doing so) division 1, and they shaved for the big events followoing a taper (methodical reduction in training before race)....referred to as a "shave and taper." The shave does little (a silicon cap is better as is a long 'fastskin' suit - cost about $550).
In cycling and swimming the shave is a ritual and somewhat psychological; routine prep for race day. It works.
My .02$
Jim