I was reading the 5 A ha moments article and was surprised to read the below. What are people's thoughts on the systemic response theory?
Ah-ha! #5: Hypertrophy is a systemic response and effect, not a localized one.
All the talk about bodypart training versus full body routines, isolation exercise versus compound exercise, etc. is based upon a fundamentally flawed concept: that hypertrophy is somehow completely regional-specific.
Here's a study that examines this in a bit more detail:
Rogers et al
The Effect of Supplemental Isolated Weight-Training Exercises on Upper-Arm Size and Upper-Body Strength
Human Performance Laboratory, Ball State University, Muncie, IN.
NSCA Conference Abstract (2000)
The researchers compared the effects of a weight training program on 5RM strength and arm circumference and divided the subjects into two groups. Group 1 performed four compound upper body exercises, while Group 2 used the same program but included biceps curls and triceps extensions.
The results showed that both groups significantly increased strength and arm size
However, the addition of direct arm training to group two produced no additional effect on strength or arm circumference after 10 weeks of training.
The additional localized training did not result in anything that the bigger compound exercises didn't provide.