What RIR is and how to use it to progress

RIR stands for reps in reserve: the repetitions you could have done and did not. If you finish a set with two left in the tank, that set was RIR 2. If you could not have done a single one more, it was RIR 0 — to failure.

It is the most direct way to write how hard a set should be, and it is what turns “4×6 with 80 kg” into a complete instruction.

RIR and RPE are the same scale seen from opposite ends

The strength RPE scale (Zourdos, 1 to 10) measures the same thing from the other side:

RPE	RIR	What it means
10	0	You could not do one more
9	1	One left
8	2	Two left
7	3	Three left

Use whichever feels natural, but use only one. Mixing both in the same programme guarantees that someone eventually reads “RPE 2” and does a warm-up set where a hard set belonged.

Why prescribe effort and not just percentages

A percentage of your 1RM assumes today’s 1RM is the one you measured six weeks ago. It is not: it moves with sleep, stress, food and where you are in the training block. Percentages describe the barbell; RIR describes what it is costing you today.

In practice they work together:

• The percentage (or the weight itself) sets the session’s starting point.
• RIR decides whether that weight goes up, stays or comes down on the day.

When the planned weight comes out at RIR 4 two weeks in a row, the load is too light and must go up, whatever the percentage says.

How to calibrate it when your estimate is off

Almost everyone starts by overestimating their RIR: they think three were left when one was. Three ways to calibrate, from least to most uncomfortable:

1. Watch bar speed, not the feeling. When the last rep gets clearly slower without any change in technique, you are somewhere between RIR 1 and 2.
2. Take an occasional set to true failure. On a safe accessory (curl, leg extension, machine row), never on a heavy squat. It gives you a reference for everything else.
3. Compare prediction with outcome. Before the set, write down how many reps you think you can do. Afterwards, count them. The gap is your calibration error, and it shrinks on its own within a few weeks.

How to use it across a block

RIR is not a fixed number: it is the variable you tighten as the mesocycle advances.

• Early weeks: RIR 3 on main lifts. Work accumulates without buying fatigue you will carry.
• Middle weeks: RIR 2, with load climbing.
• Last week before the deload: RIR 1, or RIR 0 on some accessory.
• Deload: RIR 4-5, same movements, far less effort.

That effort progression is a valid way to progress in itself: same weight, same sets, pushing a bit harder each week.

What RIR also buys you: a strength estimate

If you record weight, reps and RIR for a set, you have enough to estimate that day’s 1RM (the e1RM). A set of 5 at RIR 2 is, for estimation purposes, equivalent to a set of 7 to failure, and that yields a number you can compare across sessions.

It lets you see progress without testing a real 1RM, which is slow, risky and impossible to repeat every week.

One important detail: that estimate belongs to that day, with that day’s body weight and state. Storing it as it was and never recomputing it later is what makes a progress chart mean anything. In Tandivia every completed set keeps its e1RM exactly as it was calculated then, for precisely this reason.

One last mistake that costs dearly

Logging the RIR you were told to hit instead of the one that happened. The plan said RIR 2 and the set came out at RIR 0: what goes in the log is RIR 0. The plan is an intention; the log is data. The moment the log is massaged to match the plan, it stops being usable for the next decision, which is the only thing it exists for.