Well, if you think about it, exercise stimulates a lot of muscle growth in the beginning, but then as time goes on it becomes harder and harder to stimulate additional muscle growth with exercise... and doing the same exercises for a prolonged period will often slow the growth response as well in many people's view. So there is a kind of general attenuation to the muscle growth effects of exercise.
My point is that we should be clear in being able to at least reference studies that show that the effect of PA does not decrease over time (or at least anecdotal feedback). What I was trying to get at was whether anyone had studies that showed PA administered over a long period continued to have the same increase in mTOR signalling or if there might be some benefit from cycling it.