Usually when I am going "off", I feel a slight tremor in my right leg or some slowness.
But by that time it is always "too late", and I will go all the way off, before I can get back on. It's like slowing down and turning a massive cargo ship (lots of momentum).
However, I think I have found a "canary in the coal mine" so to speak - a wrist rotation "tremor" (think of the movement of alternately opening and close a jar) that appears before all other symptoms. I say "tremor", but it is more like a "jerky/spasmodic motion" (i.e., not smooth).
So I just tried this wrist rotation "test" as I was approaching the time of my next dose... and 30 minutes before my next dose I detected the jerky wrist rotation (with no other symptoms), and immediately took my next dose, and eventually went back on. The nice thing about it was that I only went "partially off", and the "partial off" state wasn't that bad...
Anyone else discover ways to detect an impending off period early such that they can "partially recover" without going fully off? Or is your on-to-off-to-on experience totally different than mine...
P.S., I actually did this with a simple program I wrote (like side to side tapping keyboard test) that measures the speed that I can rotate and tap the "Enter" key with my pinky and thumb (alternately)... And I found that for me, with 10 tap intervals, an average interval size < 400 ms between taps = on-time and > 500 ms between taps = off-time...