BMR / RMR65% example
Resting energy
Keeps breathing, circulation, temperature regulation, organs and basic cell function running.
Often around 60–70%IN THIS GUIDE
Does this sound like you?
Repetitions in reserve, or RIR, estimates how many more good repetitions you could have completed before technique or range of motion broke down. It is a skill that improves with practice, not a perfectly precise measurement.
THE SHORT ANSWER
For most working sets, finish with roughly 1 to 3 good repetitions still possible. Keep more in reserve while learning a movement, and use failure selectively rather than automatically.
Use effort to support technique and progression
A set at 3 RIR means you think about three more controlled repetitions were possible. 1 RIR means one good repetition remained. 0 RIR means no further repetition could be completed with the agreed technique.
Training closer to failure can be useful, but failure is not required on every set for strength or muscle gain. Very hard sets also create more fatigue and discomfort. Compound lifts, new exercises and sessions performed without a spotter usually deserve more caution.
Use the same technique, range of motion and tempo when judging effort. If the final repetitions become shorter, rushed or substantially different, the number in the log is not comparable.
Evidence & useful reading: Proximity to failure and hypertrophy review · RIR dose-response meta-regression · Failure versus non-failure meta-analysis
When to get professional help: General effort guidance is suitable for healthy adults. Seek medical or physiotherapy assessment for persistent pain, neurological symptoms, unexplained weakness or symptoms that worsen with training.
Calibrate your RIR in three steps
Learn reps in reserve. Film sets. Track load and reps. Push safely on key lifts.
Decide what counts as a complete repetition before the set. Keep range of motion and control consistent.
At the end of the set, record how many more good repetitions you believe were possible. Do not change the answer because the number looks better or worse on paper.
3. Compare with performance
Across several sessions, compare RIR with completed repetitions, load and technique. If you repeatedly finish far below the target effort, add a rep or small load next time.
Use failure selectively
Failure may be appropriate on some safer machine or isolation exercises, especially on a final set. It is not required for every exercise, and pain is never a useful effort target.
Common mistakes
Practical checklist
Set a clear repetition and technique standard
Use a target RIR for each working set
Record load, repetitions and estimated RIR
Keep range of motion consistent
Use more caution on new or complex exercises
Review the pattern over several sessions
Progress only when technique and target effort support it
Personalised support
Coaching can help calibrate effort, technique and progression so hard work is applied where it is useful.
