@knlranch #Longboarding is definitely lower impact than #running, and there are a few lesser-known styles which are even lower impact yet. Since you like #boardsports:

#SurfSkating — special board with a very turny front truck. You propel yourself forward with a series of deep, slow carves.

#LDP / pumping
Similar, only with more of a quick, wiggling motion. Like this
https://www.instagram.com/p/Cn83LoRJVbA/
Can do long distances.

#LandPaddling — #SUP on a #longboard

Or #InlineSkating looks very fun.