> Healthy, recreationally active but untrained young males Yeah this is why. Anything you do as an untrained person is going to get you newbie gains. It's just really easy to improve initially. Doesn't mean it'll work after the first 6 months
Also, it's more difficult to reach true failure with lower load, people tend to stop too early.
failing to lift is not the same as lifting until failure.
Consider, if I load up the bench press to 200kg I won't get a single rep. If I try to rep it I'll fail but I'm not lifting until failure.
If I load it up to smaller weight lets say 100kg and crank out rep after rep I'll get much closer to "lifting until failure."
When I reach the end, the last rep is a rep I won't make. But I'm still not at a point where I can't do no more, just the weight is too big, so I must reduce the weight and go again. When I do this I get even closer to "lifting until failure".
It's like integration, the smaller the infinitesimal the closer to the true value you get when you sum up (integrate) all the parts.