The following article was taken from Ergo-Log
Strength training using extremely heavy weights, with which athletes can only manage the return (eccentric) part of the movement on their own, builds more strength in experienced strength athletes than regular strength training does. This is the conclusion reached by a Finnish study published Frontiers in Physiology. Eccentric strength training requires a few weeks before the effects are seen.
The researchers got two groups of male students to train their legs twice a week on a leg-extension machine and a leg-press machine for a period of 10 weeks.
One group trained in the traditional way [TRAD]. The students did alternate sessions, using weights with which they could manage 6 reps for one, and weights with which they could manage 10 reps during the other.
The other group did eccentric training [AEL]. They used weights that were 40 percent heavier than the weights that the other group used. They could only lift the weights with help. The way they managed this is shown below.
The subjects were able to perform the return (eccentric) part of the movement, so letting the weight gently return to its resting position. The subjects in this group did the same number of reps as the subjects in the other group.
A third group of students did not train, and functioned as control group [CON].
The students had already been training doing weight training for a couple of years.
The students in both training groups gained about the same amount of muscle mass. The researchers saw this on scans they made of the students’ legs.
The figures below show that the students who did eccentric training built up more strength than the students that did traditional training. Torque = what’s called ‘strength’ in everyday language.
The increase in strength in the subjects who had done eccentric training took place in the last five weeks of the experiment. Apparently eccentric training takes more time to start showing an effect than regular training does.
“Accentuated eccentric loading seems to provide an additional training stimulus to increase maximum force production, as well as increasing work capacity/reducing fatigue during lifting in previously trained subjects”, the researchers write.
“Both the traditional and accentuated eccentric loading training programs were equally effective in eliciting increases in muscle cross-sectional area in subjects accustomed to resistance training. Mechanisms other than muscular hypertrophy, including increases in muscle activation, appear to underpin the greater improvements following training with accentuated eccentric loads.”
Source: Front Physiol. 2016 Apr 27;7:149.