Couple of comments w.r.t study design and outcomes:
There are 3 test protocols involved in the study:
1) 1 set to failure at 80% of 1RM
2) 3 sets to failure at 80% of 1RM
3) 3 sets to failure at 30% of 1RM
So the study tries to look at 2 effects on strength (and hypertrophy):
a) Effect of number of sets – 1 vs 3 sets
b) Effect of intensity level in % of 1RM – 30% vs 80% of 1RM
Results (w.r.t max strength gains – I’m not interested in hypertrophy):
• The study does confirm a difference in isotonic (as opposed to isometric) strength gains between the 80% and the 30% protocols:
<<Isotonic maximal strength gains were not different between 80%-1 and 80%-3, but were greater than 30%-3 (P 0.04)>>
• As the training protocol was not an isometric one but a concentric/eccentric protocol (knee extensions), it is to be expected from a training specificity standpoint (=neural movement adaption) to see more adaptions in dynamic strength as opposed to static strength, so no surprise here
• There was no (significant) difference btw. the 3 sets @80% and the single set @80%
Comments on study design:
The 18 young men (with their 36 test legs) selected for the study where assigned to 2 protocols each (1 leg per protocol).
1 - So we have n=12 individuals (à 1 leg) for each protocol; a fairly low number, which explains why some of the differences in outcome that may be observed do not pass the (artificial) statistical criteria of significance at a set P-level. In other words: there could be common sense evidence of a difference in outcome, even if the statistical criteria are not sufficient to back this up from a purist statistical standpoint.
2 – The test subjects are untrained (no former lifting activity over the last year); as we know that with untrained subjects, nearly ANY protocol results in good strength gains, so it is to be expected that also the 30%-protocol yields strength gains. But as we also know, the intensity threshold needed to yield similar strength adaptions with ongoing training status and history continuously increases, so this result cannot be applied to trained individuals. In other words: if you already have a strength training history as a climber (as most of us here may have), I would not believe this to be true for the training community on UKB.
3 – The application of 2 different test protocols for both legs of one test subject is also interesting: There is a known transfer from 1-sided training towards the other, untrained limb. This effect is often deliberately used when preventing strength losses during injury periods. E.g. training the healthy fingers 1-sided prevents (to a certain degree) strength loss in the injured (and thus immobilized) hand / fingers. So we could put up the hypothesis that there may be a strength transfer from the e.g. leg trained @80% to the leg trained @ 30% that biases the protocol comparisons (just realise that they acknowledge this in the discussion part of the paper)
Ups... quite long post. Got carried away