I don't think I've ever seen these sites given a formal name, but they're basically solicitation letters. Most people just call them "scams."
I can't do the research for you, but just do a search for the word "scam" right on that Tim Ferriss page for plenty of discussion, even about some of your questions here. It's not coincidental that pretty much every page of this style is about "[GREAT ABS|HOT CHICKS|MAKING MILLIONS] NOW!!!" (Or time cubes.) It's theoretically possible there are some of these sites out there that are legitimate businesses who just have bad ideas about design, but that again is your research to do. The overall aesthetic is nothing new, just an outgrowth of crappy unsolicited fliers and such that were previously sent through physical mail. They still are, but much less, in my experience.
To be fair, the Truth About Abs site shows an entirely different level of effort from the other ones, ie. the hand-drawn videos, even if it shares a lot of stylistic tics. On the other hand, it also fails your primary "single-page" criterion, so... On the other other hand, there are entire sites about how Mike Geary is a scammer, or isn't, and sometimes the same site makes both claims on separate pages, but always with affiliates links back to him. Which is...questionable.
It's unclear to me what you're looking for regarding the "science" of building them, as overall they're pretty brutally simple in any sort of structural sense. Feel free to edit your question and clarify. In terms of content, they're generally a bunch of keyword-laden ranting, backed up with large numbers of (likely purchased) backlinks, and often an affiliate program of some sort. When combined, my generalized answer to your question is "make the site as spammy as you possibly can, just be sure there's an actual product involved so you don't get shut down as an actual scammer; market aggressively, and see if you can get other people to do the work for you." Whether the product itself is of any value is a customer service issue.