You can read up on Dr. Stephen Seiler's research (or watch his lectures on YT). He is one of the leading academics in the field of endurance. His results clearly demonstrate that a "polarised" approach with at least 80% low intensity work yields superior results to more high intensity approaches even in athletes who only train for a limited amount of time each week (3-4h).

That is not to say that HIT doesn't work, and doing something is certainly better than doing nothing in any case, but if you want to maximise the training effect w.r.t. endurance for a given time budget, doing mostly LIT is the better option.

> He is one of the leading academics in the field of endurance. His results clearly demonstrate that a "polarised" approach with at least 80% low intensity work yields superior results [..]

(Sorry, I have to ask) but results in what?

It sounds like there's a risk of focussing on (endurance) athletes, not on unfit sedentary desk workers. Talking about which of the former benefits most from which particular training methodology could be missing the point, which is that it's the latter who are the group who really need to get off our backsides to improve our general health.

In other words, getting a few extra % of performance out of already fit people is of interest to a minority, but is irrelevant as far as public health policy is concerned.