"Overall, moderate volumes (≈30–60  repetitions per session  for DER training) appear to yield the largest  responses." An exception  to this is with very high loads (90%  1RM or 120% to 230% 1RM with  eccentrics) where high rates of growth have  been shown with volumes as  low as 12-14 repetitions per session. To  date, relatively few studies  have directly compared the effects of  different volumes of work on the  hypertrophic response as measured by  scanning methodology." The paucity  of data clearly warrants  further research.
		
		
	 
Preceded by ...
	
	
		
		
			Results
No relationship could be found between frequency of training and the   increase per day in muscle cross sectional area. When the intensity was   plotted against the rate of increase, a weak tendency was found for the   rate to increase with increasing intensity. The highest rates of   increase tended to occur around 75% of 1RM. When volume was plotted   against the rate of increase, greater gains in muscle mass were seen   initially with increasing volume while there were diminishing returns as   the volume increased further. The highest rates of increase tended to   occur with 30-60 repetitions per session.
		
		
	 
But then when I read the conclusion summary it says:
	
	
		
		
			For the total volume or duration of activity, the  results suggest a  dose-response curve characterised by an increase in  the rate of growth  in the initial part of the curve, which is followed  by the region of  peak rate of increase, which in turn is followed by a  plateau or even a  decline. It is recognised that the conclusions drawn  in this paper  mainly concern relatively short-term training in  previously untrained  subjects and that in highly trained subjects or for  training studies  extending for several months, the dose-response trends  and the  hypertrophic effects of different modes and types of strength  training  may be very different.
		
		
	 
All this says to me is that lighter loads need more repetitions to induce hypertrophy and that heavier weights induce more hypertrophy.
And then there's this:
	
	
		
		
			Training Implications and Recommendations: For your typical  "dynamic  external resistance", recommendations are  given for "Moderate load  slow-speed training",  "Conventional hypertrophy training", and   "Eccentric (ecc) overload training". These three modes  are denoted as  suitable for beginners, novice-well trained, and  advanced-elite,  respectively. For the "Conventional hypertrophy  training" for the  novice to the well trained, they recommend  an 8-10RM load (75-80% 1RM),  with 8-10 reps to failure or near failure,  1-3 sets per exercise,  progression from 1–2 to 3–6 sets total per muscle  group, moderate  velocity (1-2 seconds for each CON and ECC), 60-180  seconds rest  between sets, and 2-3 sessions per muscle group per week
		
		
	 
Which at worst appears contradictory to much of the information in their own study, or at best reads as a highly speculative derivative of the results.
Consider comparing the low and high points of their recommendations; 10RM load, 10 reps per set, 1 set per muscle group and twice per week. and then 8RM, 8 reps, 6 sets per muscle group, three times per week.
That's an extraordinary difference in workload.
Their own study says that 30-60reps produced the most hypertrophy, 
except for 90% 1RM and 120-230% eccentrics, so why not use the result which actually produced the most hypertrophy ... ? Granted this isn't the actual study, and just a cut&paste of the most relevant paragraphs but still. It's disconcerting that they then make this statement 
	
	
		
		
			You often hear statements  like "eccentric training produces the  greatest muscle  hypertrophy". "This review demonstrates that given   sufficient frequency, intensity and duration of work, all three types of   muscle actions can induce significant hypertrophy at impressive rates   and that at present, there is insufficient evidence for the superiority   of any mode and/or type of muscle action over other modes and types of   training in this regard." In fact, the data suggest that pure   eccentric training is inferior to both concentric and   eccentric+concentric training, though this is still a subject of debate   rather than a scientific certainty.
		
		
	 
 - so which is it?
Furthermore, the recommendations they have appear to be completely at odds with the training methods used by just about anyone who naturally (without chemical assistance) puts on significant muscle mass, including a significant # of lifters on this site.
And I guess the last issue I have with this study, beyond ancedotal experience (mine and reported by others here, elsewhere) is that it's still just one study and somewhat at odds with other studies. So which do you/we follow and how does one determine where the weight of authority falls?