My hand-wavy anectdata checks out with the author's. After a broken leg, I had a 2 year long sedentary period in which I gained 20 pounds.

I burned it off using HIIT and it took a little more than a month. I noticed results right away, and kept going until I was done. I ate according to my appetite.

I don't get these kinds of results doing either regular endurance or strength training.

As he correctly states- even n1 can lead to science, especially if everyone published similar journals there’d be a lot of ns.