Classic bench press just as effective as bench press with unstable weights
Strength athletes looking for a different way of training their pecs now and then can do bench presses with unstable weights. This alternative is just as effective as doing ordinary bench presses, according to sports scientists from California State University, who will soon publish an article on this in the Journal of Strength and Conditioning Research.
The researchers got 20 male students, all of whom had been doing weight training for several years, to do three successive reps of bench presses. The researchers had attached electrodes to the muscles involved in bench presses so that they could see how hard these muscles had to work.
The students had to do the bench presses on one occasion with a bar to which weights were attached in the normal way, but also on one occasion with the weights attached differently: the researchers had attached a 16 kg weight to either end of the bar with a rope. This made the bar unstable as the weights swung during the movement. The clip below shows what happens.
We'll confine ourselves to what happened when the subjects did bench presses with 80 of their maximal weight. The researchers also got the students to do the exercise with 60 percent of their maximal weight but the results were approximately the same.
The researchers recorded a little more electrical activity in the muscles during both the concentric and eccentric movements. That would suggest that the unstable version of the exercise stimulates the muscles a little more intensively – or it would if the differences had been statistically significant. But they weren't.
"The lack of significant differences in muscle activation between stable and unstable bench press may allow use of unstable loads by practitioners to add variety to resistance training programs", the researchers concluded. "Also, since some sports, such as football, require the movement of unstable objects, the use of instability in training may provide a more specific stimulus then stable."
"However, a lack of difference between conditions in this study demonstrates that there appears to be no advantage or disadvantage to the use of an unstable load in the bench press."