RPE = Rate of Perceived Exertion.
It tells you how hard a set felt.
RPE 6 = 4 reps left
RPE 7 = 3 reps left
RPE 8 = 2 reps left
RPE 9 = 1 rep left
In Iron Habits, most main lifts live at RPE 7–8.
Why?
Because:
• It builds strength without burnout
• It protects technique
• It allows consistent progression
• It prevents ego lifting
You do not need to hit failure to grow.
Intensity should be controlled — not chaotic.
Master RPE and you master progression.