(Not that this is bad news regardless, it's good to have tools in the toolbox and some people might prefer lower time higher intensity stuff, but I do think the result is pretty limited)
And admit it, no matter how busy you are you do watch some entertainment once in a while.
Likewise, in 10 minutes you can watch some short youtube video. The point is not that you can sweeten the deal of the 45 minute work-out to make it more bearable, the point is that when faced with 10 minutes of exercise vs 45 minutes of exercise, 10 minutes is a much easier pill to swallow _and_ is infinitely better than 0 minutes.
I'm glad that you have unlimited reserves of willpower and have no trouble with procrastination and as a result can just do any task on demand no matter how seemingly unpleasant it sounds, but unfortunately almost nobody on this planet is like that.
This research is very positive and useful to get people who are currently doing 0 minutes of exercise a week to do 30 minutes of exercise a week, it flies in the face of a lot of "if you don't exercise for at least x minutes a week, you might as well not be exercising" bullshit.
30 minutes of exercise per week (it doesn't really matter if it's high-intensity or not) is really much much better than 0.
Most fit people have pretty good intuition about their bodies. They choose appropriate workouts, they don't run at high intensity too long and give themselves a stitch when they're meant to be doing endurance training, they know what it feels like to be lazy versus what it feels like to need a lower intensity rest day, they enjoy at least some of the exercise they do. When a sedentary person starts exercising on their own, they often don't know the benefits of training at a lower intensity, and adopt a "no pain no gain" approach, which is counterproductive if it doesn't build on a solid foundation of good habits.
With a form, if you are going to claim that everyone must start with personal trainer to correct their crunches or squats form, pretty much no one will start exercising anymore. That is just going to be too expensive and time consuming. And among people I know who regularly exercise, none of them started with a trainer.
I had exactly opposite experience. Time cost is rather major thing. Especially in the beginning, because it makes organizing your day much harder. Add an hour of anything and suddenly you dont have time to shop or cook or socialize or simply for your favorite hobby. Small time investment make it easier to transition and change lifestyle.
And second, allowing myself to cheat and skipping does miracles for my ability to keep the activity long term. Whenever I set hard requirements on myself, following up became impossible in the long term. And since the attitude is all or nothing, it dropped to nothing.
And third thing that does miracle for gaining long term habit is to prioritize pleasurable exercise, the one I actually like, rather then theoretically most effective one that sux.
Where are you getting that from? Are the changes seen in the fitness factors especially significant, and if so, how significant? What's the expected health outcome here?
It takes awhile to get your lactic clearance up. Most people will quit after a few workouts because literally feeling like you are going to throw up is not fun.
It is January so the gym is loaded with the New Years resolution crowd still. Most the people who started doing HIT on Jan 1st will quit by mid Feb. It is almost like clockwork and why I always reset and make January my recovery month.
If anything HIT is probably a net negative because if you are out of shape it is just reinforcing the idea that the gym is a painful and miserable experience.
There is a huge difference between killing yourself over your lunch break/before dinner at home, and then taking a quick shower, and having to cut more than an hour out of your day because you need to drive to the gym, kill yourself for a very short period of time, then take several minutes to recover enough to feel you can safely drive home as a gross sweaty mess because you're far too uncomfortable showering around a bunch of strangers at the gym, and then do that multiple times a week. That's not just a commitment, that's a complete daily habit overhaul. Your life is now dominated by having to go to the gym.
Folks who decide "yes, I think I can spend 15 minutes a day, three days a week, on this" at home, with some expert advise from reputable fitness coaches who run also youtube channels, without any of the time investment, inconvenience, and complete upending of daily routines that comes with attending a gym, might have a different success rate (and we'll never hear from them. If they keep it up, they just get in a bit better shape and move on with their lives).
This seems like a pretty negative reading. How about:
Sedentary people (who have the most issues and highest healthcare costs), can see significant improvements in health by exercising for a fraction of time normally recommended.
Sounds like wins all around.