Been training since the mid 80's. I change routines around here and there. No longer need to go super heavy. Currently doing full body workouts M/W/F which has me in and out of the gym in about an hour.
Same here. I started lifting three days a week, doing cardio three. I do legs or running in the morning, upper body or other cardio after work. Evening workout wakes me up after a day of sitting at a desk (or standing).
Like many others, i be become increasingly instinctual over time. I pretty much always do the same exercises, but reps and sets are never the same. I back off and push on as I feel -- no longer forceyslef to get X reps or sets if its feeling bad.
I feel a lot better this way. Before, I would always ignore pains and try to tough it out. In the end, though, that approach just led me to ignore my body's feedback... I got lost.
Once I started adjusting things based on how I felt instead of blindly 'soldiering on' and trying to hold myself to a 'rational' plan, I finally started feeling pretty good about my workouts. Well, for the past year or so anyway...