STEADFAST TRAINING GLOSSARY
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Understand your effort. Give every set a purpose.
WHAT ARE REPETITIONS IN RESERVE?
Repetitions in Reserve, or RIR, is your estimate of how many more repetitions you could complete before reaching failure in a set. For practical coaching, count repetitions you could perform with the agreed technique and range of motion.
If you finish eight repetitions and believe you could complete two more, you would record approximately 2 RIR. This is an estimate of remaining capacity, not a measurement of pain or breathlessness.
Zourdos and colleagues’ 2016 study examined a resistance training effort scale incorporating RIR.
WHY IT MATTERS
The same weight and repetition count can feel different across days. Recording RIR adds context to your training log and gives you and your coach a shared way to discuss effort.
- Plan: Give a set an intended effort target.
- Observe: Compare the target with what you experienced.
- Adjust: Use that information alongside technique and recovery when planning the next session.
READ THE RIR SCALE
| RIR | What you estimate |
|---|---|
| 4+ | At least four more repetitions available. |
| 3 | About three more repetitions available. |
| 2 | About two more repetitions available. |
| 1 | About one more repetition available. |
| 0 | No additional complete repetition available. |
These numbers describe proximity to failure. They do not prescribe the best target for every person or exercise.
RIR IN PRACTICE
If the set differs from the target, tell your coach and use the information to guide an appropriate adjustment. You do not need to perform the extra repetitions just to record an estimate.
HOW ACCURATE IS IT?
RIR is useful feedback, but it is imperfect. A review found substantial variation in how accurately people predicted repetitions remaining. Training experience alone did not guarantee accuracy. Treat the number as an estimate, especially when a movement is unfamiliar. Read the review by Halperin and colleagues.
TRAINING QUALITY & LIMITATIONS
Use consistent technique when comparing sets. RIR does not replace individual exercise restrictions or instructions from a clinician. A low RIR target is not a reason to push through pain.
FREQUENTLY ASKED QUESTIONS
Is RIR the same as the repetitions I completed?
No. Repetitions completed describe your work. RIR estimates how many more were available when you stopped.
Is RIR the same as RPE?
No. RPE means rating of perceived exertion. Some strength training RPE scales use RIR as an anchor, but other RPE scales measure effort differently. Specify which scale your program uses.
Do I need to reach 0 RIR every set?
No. Reaching failure is not required for every set. Your effort targets should reflect the exercise, your goals, and your training plan.
How does RIR connect to progressive overload?
It adds context. More repetitions at the same weight and a similar RIR can suggest increased capacity. Compare similar conditions across sessions before deciding to progress.