I got very interested in this kind of stuff a few months ago in an effort to get better at climbing.
I can't access the full paper but going from the abstract, this result isn't super surprising for two major reasons: mainly that once a week isn't often enough, and the once-a-week workout group might also be doing unnecessary muscle damage with such a heavy workout. It would be interesting if they had included more groups that did more reasonable workout schedules like twice or three times a week with three sets a day. I imagine those groups would see better results than the 5-days-a-week group. A further caveat is that the abstract doesn't mention if the individuals are untrained. Assuming they're untrained, that often explains a lot of the gains you see in these papers.
That's not to say this is unimpressive. For sedentary people, it means that just a small amount of non-exhausting exercise can make significant changes to the body. These researchers actually have another paper from earlier this year that shows that just squeezing your muscles can result in 10% strength gains (https://onlinelibrary.wiley.com/doi/10.1111/sms.14138?af=R)
I can't access the full paper but going from the abstract, this result isn't super surprising for two major reasons: mainly that once a week isn't often enough, and the once-a-week workout group might also be doing unnecessary muscle damage with such a heavy workout. It would be interesting if they had included more groups that did more reasonable workout schedules like twice or three times a week with three sets a day. I imagine those groups would see better results than the 5-days-a-week group. A further caveat is that the abstract doesn't mention if the individuals are untrained. Assuming they're untrained, that often explains a lot of the gains you see in these papers.
That's not to say this is unimpressive. For sedentary people, it means that just a small amount of non-exhausting exercise can make significant changes to the body. These researchers actually have another paper from earlier this year that shows that just squeezing your muscles can result in 10% strength gains (https://onlinelibrary.wiley.com/doi/10.1111/sms.14138?af=R)