The short description of the study in the link indicates 4x4 minute intervals at 85-95 percent with rest between sets which seems more like VO2Max intervals than HIIT and is described as High Intensity Interval Exercise, your description is closer to ballpark what I know of as HIIT, sometimes called Tabata intervals, which definitely need a warmup that depends upon you but 20-30 minutes is the minimum I strive for.