Wednesday, August 31, 2011

Exercise to activate the core

Not sure how much this tells us.    Basically standing one arm presses cause more activation of the "core" than doing them seated with both arms.

Muscle activity of the core during bilateral, unilateral, seated and standing resistance exercise
Little is known about the effect of performing common resistance exercises standing compared to seated and unilaterally compared to bilaterally on muscle activation of the core. Thus, the purpose of this study was to compare the electromyographic activity (EMG) of the superficial core muscles (i.e. rectus abdominis, external oblique and erector spinae) between seated, standing, bilateral and unilateral dumbbell shoulder presses. 15 healthy males performed five repetitions at 80% of one-repetition maximum of the exercises in randomized order. Results were analyzed with a two-way analysis of variance and a Bonferroni post hoc test. The position × exercise interaction was significantly different for rectus abdominis (P = 0.016), but not for external oblique (P = 0.100) and erector spinae (P = 0.151). The following EMG results were observed: For rectus abdominis: ~49% lower in seated bilateral versus unilateral (P < 0.001), similar in standing bilateral versus unilateral (P = 0.408), ~81% lower in bilateral seated versus standing (P < 0.001), ~59% lower in unilateral seated versus standing (P < 0.001); For external oblique: ~81% lower in seated bilateral versus unilateral (P < 0.001), ~68% lower in standing bilateral than unilateral (P < 0.001), ~58% lower in bilateral seated versus standing (P < 0.001), ~28% lower in unilateral seated versus standing (P = 0.002); For erector spinae: similar in seated bilateral versus unilateral (P = 0.737), ~18% lower in standing bilateral versus unilateral (P = 0.001), similar in seated versus standing bilateral (P = 0.480) and unilateral (P = 0.690). In conclusion, to enhance neuromuscular activation of the superficial core muscles, standing exercises should be used instead of seated exercises, and unilateral exercises should be used instead of bilateral exercises.

1 comment:

Anonymous said...

In my experience this seems true, at least in regards to muscle activation. Anytime I do unilateral horizontal pushing/pulling on a Free Motion cable machine my "superficial core" muscles fatigue, much more so than when I do anything sitting or bilateral. If I add a touch of rotation to the push/pull then the fatigue gets even greater. Same when vertical pushing, I can feel the "superficial core" muscles engaging in a stabilizing effort, especially the contralateral obliques.

I think the conclusion should not be used as a general training guideline but should be considered withing the scope of specificity and individuality. For me, I mix it up and will train unilaterally a few times a month.