RIR
RIR means repetitions in reserve. It is your estimate of how many more reps you could do before failure.
RIR: a practical example
For example, you finish a set believing you could complete two more controlled reps and record 2 RIR.
Use it in your log
When you log your workout, keep this in mind: it is an estimate that depends on experience and technique. It is not a measurement of effort by the app.
Next, use the workout log to keep names, weights and reps in one place. Then check your progress across sessions.
Related terms
These examples explain terms. They do not tell you what to lift. If you need help with a plan, ask a qualified trainer.
Updated October 22, 2026. For more context, read the ACSM training guide (2009). However, terms can vary by plan.