[storus]

4-minute HIIT run (30s full/5s walk, repeat) makes you vomit and not feel your legs. 15 minutes of HIIT 5-times a week is a wishful thinking. It's not your typical "vigorous" activity. At my athletic very best I could at most chain 3 HIITs in a row and be destroyed for a few days.

[solraph]

Fair enough, I don't think it changes my the conclusion though.

On that basis, I would say that someone whose entire exercise regime is doing HIIT a few times a week for 8 minutes (24 minutes in total) is not going to be hitting the 6x multipler required for an equivalent of regular 150 minutes of exercise.

[storus]

Look up Tabata intervals, used to train speed-skating Olympians.

[solraph]

If that is the entirety of their training regime, I will simultaneously be amazed and change my opinion.

However, I still maintain that if someone is _only_ doing 8 minutes of HIIT 3x times a week, it is not equivalent of a getting 150 minutes of regular exercise per week.

Without further context, it's impossible to comment further.