You didn't answer the question? You didn't explain the training methodology and without access the full article, I can't read for myself what the methodology for the eccentric sets vs concentric. You don't tell us how much weight they lifted, how long the eccentric reps last etc. To be honest the blog title is pretty misleading - I can't find any evidence in your article to lift less and gain more muscle. All you said is the eccentric group did less reps but you don't provide us any context.