Pretty much what the article alludes to, yes. Though, my Dr advises that it's best to get my HR up (to a level he recommends) and sustain that for 20-30 min per day* rather than break it up. But he also still says move every hour. So...
* Minimum
* Minimum
By contrast, HIIT research suggests you really only need to hit max heart rate and VO2max for < 4 minutes 3x a week for effectively all the benefit.
The "interval" idea is 4 sprints of 30 - 45 seconds to go into max heart rate band, each with a 30 - 15 sec recovery to let heart drop a touch, then hit the next one. You are not doing aerobic exercise, you are pushing into anaerobic.
They also suggest a warmup and cooldown of at least a couple minutes, so put that together and you're looking at 8 minutes 3x a week.
The problem is that the first I in HIIT is much too much Intensity for some. Fitness clubs had to get rid of or gate HIIT machines because guests would vomit. If you're doing it right, you will be anaerobic, many people don't tolerate that without working up to it, and people hate working up to things.
Supposedly -- though less research on this -- the same routine will "upshift" metabolism so after 6+ weeks of accommodation, your 24 hr calorie burn from these 8 mins 3x a week is greater than if doing traditional hour long fitness routines every day, and that upshift can last 6 - 9 most after cessation of the routine.
A lot of people just can't go from sitting on their buts all day to sitting on their buts all day with the addition of a daily vomit enducing HIIT routine. They would explode.
Probably best to start by walking, then walking briskly, etc...
And as you get fitter you can just load more weight/exercise type.
Of course it comes with the taste of bile….