What is the correlation between cardiopulmonary efficiency and intelligence?

What, if any, relationship exists between a person's lung capacity and circulatory efficiency and its effect upon cognition; be it concentration, memory storage and recall, learning, visuospatial ability, verbal fluency, and processing speed. Does one with a higher cardiopulmonary efficiency exhibit a likewise increased intelligence quotient, or are the two factors generally irrelevant towards each other in the absence of any pathology (e.g. cognitive dysfunction in patients with COPD)? If a correlation is present, would increasing cardiopulmonary efficacy facilitate an increased IQ, given the nature of this sequela? Please provide clinical or research evidence to support any claim.