Just for starters........pay more attention to the sources, not the article.
http://www.cyclingweekly.co.uk/healthandfitness/538109/strong-to-the-core.html
"When you cycle, you need to be able to create force from your legs, and transfer that force through your trunk and through to your upper body. If you think of your trunk as a cylinder, you have a number of dial-ups coming off, which are the muscles. Think of how many muscles are attached in that area. All of them need to be up to a certain level to be able to stabilise the trunk optimally. And that's how I envision it. We try and cover the whole cylinder.
"What I explain to the endurance riders is that if they can increase the total amount of force they can create from their hips and extensors, then they should become more efficient when riding as they won't be pushing as hard."
Martin
Evans, strength and conditioning coach at British Cycling