Continued - that is low in intensity and steady in state is now referred to as “cardio.” The term aerobics is actually his creation. It is not really a word with any formal definition, but rather a noun used by Cooper to categorize his particular approach to training. Aerobic, in contrast, is a word that has a formal definition; it is an adjective that describes a particular metabolic pathway and means, literally, “with oxygen.”
The aerobic pathway is a segment of the totality of metabolism, but what is lost on many folks who exercise is that there are other metabolic segments as well that, collectively, work together to ensure the total health of the cell and, by extension, the health of the organism that the cells collectively work to support and sustain.
Cooper believed (falsely, as it happens) that the aerobic subsection of metabolism was the most important—more important, in fact, than the totality of metabolic pathways that contribute to human functioning and health. He maintained that this one subsegment of metabolism could and should be isolated and trained.
His belief in this regard has since been shown to be without foundation. The first problem is the belief that the aerobic metabolic pathway can in fact be isolated from the rest of metabolism.
The reality is that metabolism is an uninterrupted whole that is intrinsically tied together. The aerobic machinery is fueled by the substrate pyruvate, which can be produced only through the anaerobic pathway.
Even at this most fundamental level, the interrelatedness of what Cooper believed to be antipodal elements of metabolism is self-evident.
Sorry, "Body by science"
this blokes an MD, turned weight lifter.