I can't remember which decade he's talking about or verify his claims, but in Shoe Dog the creator of Nike talks about how running for exercise was viewed as very weird in the last century, and he implies that Adidas pretty much singlehandedly changed public perception on this. Not that nobody did it, but that it was considered very weird and rare.

He was only talking about running, not exercise in general, but I seem to remember Schwarzenegger reflecting similarly about the public perception of weight lifting