i think all of the above are correct. i only have one fact to add. many clients personal life can affect their training. i have found it to be hard to decide if it is overtraining or emotional stress from the outside. I usually have a good repore with my clients so, i just ask. Sometimes their training is all they have to comfort them. so, i make adjustments in the program to suit there need at that time. It is a hard world out there.