In this video from the 50's, we see a fellow practicing cross country skiing during the summer. In order to do this, he uses "skis" with wheels on them.
The man rides these snowless skis around on the pavement using ski poles to propel himself forward. The wheel skis look like they go pretty fast, and look like a lot of fun. I'm not a fan of snow sports, and would much rather take a ride on these instead.
From the wonderful Got Weird on Instagram: "Skis without snow! In the early 1950s, when cross-country skiing started to evolve to a serious competition sport, the necessity for good summer training grew."
See also: POV ride of Kennywood's Jackrabbit in the 1930s