What I have found, studying the transformation process is that it’s never a question of coaching too long, but if one coaches for too brief of a time, the changes they desire; both on the inside and the outer results they want, won’t “stick” and they’ll slide back to where they were. Remember, The Resistance Cycle is lurking ready to pounce and push you back to who you were and what you had.
This is why, ideally, I recommend coaching for at least 90 days, though longer does result in an easier, more pronounced, and longer-lasting result.