> First of all, I've been lifting for many years and I haven't done dumbbell curls in a decade.
The study authors aren't arguing that dumbbell curls should be the center of your workout. And they are are presumably using an isolation exercise because it is more straightforward to test improvements to strength when you are just examining the effect on a single muscle group.
> >It found those who only lowered a weight saw the same improvements as those who raised and lowered weights — despite only performing half the number of repetitions.
> No shit. That's because eccentric exercises are far more fatiguing for the muscles.
It is a giant pet peeve of mine when scientists run a diligent study and then the response is "No shit, that's common sense" with the audacity to call it "junk science." Putting actual data and numbers behind a "common sense" belief is what science is all about - it is not "junk science".
I think there are other fair critiques about the applicability of this study (for example, another commenter mentioned that they were dealing solely with untrained individuals), but the fact that they used dumbbell curls isn't one of them.