Originally Posted by
phrantic09
This...
strong core results in negligible weight on arms
Mentions of "core" always raise a red flag for me. As I've always understood and experienced in my riding, if the bike fit is right for the effort level that you're maintaining, there's negligible weight on your arms because your upper body is supported by pedaling effort, and the core isn't involved at all. To put it another way, any energy expended by invoking the use of core muscles is energy that could and should have gone into pedaling.
In fact, in decades of following discussions of bike fit and riding technique, especially for racers, I never came across the term "core" (or any prior variation) until it started popping up in Bike Forums a few years ago. I assume that it's a term used by body builders and gym rats that's been ported over to bike websites because it sounds vaguely hip and lends an air of authority to the rest of the sentence.
The "core" might be of concern to track racers and road sprinters and to those with various physical deficiencies, but I don't see the point of what seem to be incessant mentions of the core whenever threads like this one crop up.