OnlyResting- It seems like the AT calculation formula is a good general guideline as a place to start, and then to modify as our own unique physiological characteristics warrant. I can barely leave the house right now for doctor appointments and lab tests; getting any kind of tests would be overwhelming to me right now, the AT calculation is definitely preferable for me. I like your idea of devising a standardized routine. That's what I'm trying to figure out, too. Something that works within my schedule and capabilities right now, but allows me to tract progress (hopefully) in an objective manner.