The idea came from mkyayl’s program.
Week one is all upper body. Hard with varrying rep scheme and loads. Similar to waterburys HFT changing rep patterns. But, you do 2 exercises for a body part. E.g. bench and flys, rows and pullups etc.
You do this 4 or 5 days in the week, hopefully not in a row. Thats a lot of stress to stimulate hypertrophy.
Then, week 2 is lower body. Deads, squats, lunges, Snatch/Clean etc.
Week 3 is back to upper body.
Theoretically that is plenty of rest to allow for recovery and injury prevention, plus plenty of stress to stimulate growth