there's nothing contrary to what's be said here in those links - "low intensity" and "high intensity" mean something very different to most folks who don't really train. 50% (as the usnews link suggests) isn't low intensity - that's no intensity. and 75% isn't high - "moderate," maybe.
this is why knowing your AT is a good thing - personally, if i'm around 87% of my max, then I know i'm about to get anaerobic and switch my fuel source and that i can only maintain my current intensity for certain, limited amount of time before major system failure.