Reps in reserve: what 2 RIR actually means

The RIR and RPE chart

In resistance training, the RIR-based RPE scale expresses the same estimate in a different form. Near the hard end of the scale, RPE 10 corresponds to zero reps remaining, RPE 9 to one, and RPE 8 to two. This is a lifting convention; other RPE scales measure effort differently.

An example you can put in your log

Suppose your plan says “bench press, 3 × 8 at 2 RIR.” Select a load that lets you complete the planned reps while leaving roughly two more available. Your estimate is made at the end of each set. The same load can feel harder in later sets.

A record might read “60 kg: 8 reps at 3 RIR, 8 at 2 RIR, 8 at 1 RIR; two-minute rests.” That is more informative than marking the entire exercise “easy.” Next session, you can compare the load and reps alongside the effort estimate.

If you change the load between sets, record each load separately. If you reach your planned stopping point earlier than expected, write the reps you completed rather than filling in the target from the program.

How to make the estimate more useful

1. 1Define a complete rep for that exercise. Keep range of motion and technique consistent.
2. 2After the set, ask how many more reps you could have done before another complete rep became impossible.
3. 3Record a whole-number estimate promptly. “About 2 RIR” is sufficient; decimal precision adds little.
4. 4Keep exercise setup and rest periods in the notes when they changed.
5. 5Look at comparable sets over time. Treat an uncertain estimate as uncertain rather than changing your program from one number.

Why your estimate can be wrong

RIR is a judgment, and people do not always predict the remaining repetitions accurately. A study across four resistance exercises found larger underestimates at lighter relative loads. This can lead someone to stop earlier than their intended effort target.

A second study of repetitions-to-failure estimates found smaller errors when people were closer to failure. These findings are reasons to use the number as an estimate, rather than a precise measurement of what your muscles can do.

A slowed rep alone does not prove zero RIR. Likewise, feeling out of breath can make a set feel difficult before the target muscles reach their limit. Keep the estimate tied to another complete repetition of the same movement.

Choosing an effort target

Use the target in your program. The chart translates the notation; it does not prescribe how close every set should be to failure. Exercise choice, training goals and fatigue all affect how an effort target is used.

The ACSM’s 2026 summary says training to failure is not consistently necessary for the average healthy adult. You do not need to take every set to your limit to make a training log useful.

Stop for pain or loss of control rather than treating those signals as evidence that you reached the correct RIR. An effort scale cannot assess an injury or check your technique.

Who SayLift is for

SayLift is for iPhone lifters who want to record the sets they performed and carry that history into the next session. Voice logging captures exercises, reps and weights, with a review screen before the entry saves. Extra context can live in exercise notes.

Keep RIR in a note if you use it. It is your estimate, and the app’s next-weight recommendation is not a measurement of how many reps you had left. Try SayLift on iPhone to keep the workout record alongside that context.