I noticed on an article linked in a thread about wide/close grip curls that the author mentioned quit doing an exercise after 2 to 3 months and change to a new one. Now I've heard this before and it always seemed kind of like an urban myth (I can imagine how when people start a new exercise then get stronger from it due to neuromuscular effeciency they think they gained a bunch of new strength).
I'll assume that you mean this article
that was linked to by this post
I'll have to get back to you sometime tomorrow. Changing routines periodically is something that I've done for several years now, although I can't point to any scientific studies to back that choice up now. It could very well be an urban myth that I've adopted. Until then, perhaps we can agree that the hypothesis that the body's tendency to adapt to specific training makes the need for variety in training is at least plausable.
And obviously there's some exercises you should never quit doing, like squats, deadlifts and benchpress, right?
During late 2004 I temporarily ditched the standard back squat from my routine in favor of the barbell hack squat and sumo (wide) squat. The reason was because I had gotten stale in the squat. When I went back to standard back squats in Spring 2005 I was able to get past a sticking point by 30 lbs within 6 weeks. Currently, I'm using the front squat for my quads. Next, I'm toying with the idea of improving my flexibility
so I can do full squats.
As for the bench press, there was a time when I did
have to quit doing them, because of tendonitis in the rotary cuff. Even today, I use dumbells, inclines and dips more than flat barbell bench