I am no expert but I tend to read a lot of studies and interviews/talks with Phd's regarding fitness, and the consensus is that the most important predictor for muscle growth is volume (time under tension). That is, the longer your muscle fights the load, the more you grow, provided you have sufficient nutrition and rest.
Everything else (time of the day when you work out, number of repetitions / series, specific exercises, etc) is secondary and seems to only matter insofar as it allows you to stay more time under tension...
So I'd be VERY sceptical of anyone who claims you can have great results in X minutes a day.
With that said, it takes very little time under tension for a newbie to stimulate growth. But that effect doesn't last for long.
The cited study specifically says that muscle growth (hypertrophy) does improve with volume, from 1 to 3 to 5 sets, but that strength gain doesn't differ significantly. There's a lot of conflation between hypertrophy and strength. You can be strong without being big (up to a point) and vice versa.
This reinforces what strength athletes have said for a long time. The point was that in this short study, strength came from intensity (weight lifted) and size came from volume. (Hence a powerlifting program might have 3 sets of 3 to 5 of 5, whereas bodybuilding programs have much higher volume at lower weight.)
This isn’t surprising; strength gains are substantially neurological. Over time, though, you still need more muscle to move heavier weight.
I know a some powerlifters, and their personal size varies with their volume (and whether or not they want size). Some are deceptively small for the weight they can move. That being said, you can’t deadlift 500 pounds without putting on some significant mass, either.
True, in general amount of strength is correlated more with the amount of weight lifted, while ability to exercise for longer shows a more positive correlation with longer, smaller weight sets - and hypertrophy sees similar results with both methods given equal time under tension.
But the title specifically states "to look and feel better", and strength alone won't do much in regards to a persons' appearance.
I'd also like to know the starting point of the study's subjects. Although the study does mention "healthy resistance trained men", I'd guess that they were starting from a state that was low enough to achieve strength gains with relatively low exposure to weightlifting.
You are correct IMHO. We've already done this fad in the 70s when it was called HIT. It was junk science in the 70s, and it still is today. however, any training is better than no training.
Everything else (time of the day when you work out, number of repetitions / series, specific exercises, etc) is secondary and seems to only matter insofar as it allows you to stay more time under tension...
So I'd be VERY sceptical of anyone who claims you can have great results in X minutes a day.
With that said, it takes very little time under tension for a newbie to stimulate growth. But that effect doesn't last for long.