Large Caloric Deficits + High Level of Exercise

Raddichio

I came across this article, and it made me think of some posts where people say they have been eating a very low calorie diet and doing intensive, freqeunt exercise, but they're not losing weight. I'm wondering what those of you who have more knowledge about this subject think the article at the following link makes sense?

http://www.bodyrecomposition.com/fat-loss/why-big-caloric-deficits-and-lots-of-activity-can-hurt-fat-loss.html