Training article
Training By Feel: RPE and RIR
Two letters that make percentages more honest
General information about training and eating, not personal advice. It is not medical or dietary advice and it cannot account for your circumstances. If you are pregnant, have a medical condition, take medication, or have a history of disordered eating, talk to a GP or a registered dietitian before changing how you eat or train.
RPE (Rate of Perceived Exertion) and RIR (Reps in Reserve) are two ways of describing the same thing: how many more reps you could have done at the end of a set. RIR 2 means you stopped with two reps left in the tank; that's roughly RPE 8 on the more common 1–10 scale.
A percentage on paper assumes your 1-rep max is accurate and that you're feeling exactly the same every session — neither is ever quite true. If a wave's "80% for 5" suddenly feels like an RIR 0 grind instead of the RIR 2–3 it should be, that's useful information: your true max has probably moved, or you're carrying fatigue from somewhere else in life.
On accessory work especially, aim to leave 1–3 reps in reserve on most sets, and treat RPE as a sense-check against the numbers on the bar — not a replacement for them.