I’ve been running upper/lower templates for a few months now at least (2nd Gen Strength and PB templates), and am now on week 2 of the new full body Low Fatigue templates. I was finding that the dedicated upper/lower sessions were too high of an acute training load for me (especially mentally) and was craving full body so nothing was ever completely taxed on one day.
I just had a minor pec strain after close grip benching on day 4 of week 2. Could it be possible that this may have been influenced by the switch from benching 2x/weekly to 4x/weekly?