For all we know, there is a link between cardiac/circulatory problems and arteriosclerosis (that is, loss of elasticity of the vessels).

So it could be that exercise helps keep this elasticity, the same way maybe sauna does? Also antioxidants from vegetables etc.

So it could be that it is a _factor_, but definitely needs way more study.

I am also not in the medical field, but I think arteriosclerosis is a well known link for cardiovascular disease.