RIR stands for reps in reserve. It is a simple way to describe how challenging a set felt based on how many additional reps you think you could have completed.
A lower RIR, such as 0–1, means you were very close to your limit.
A higher RIR, such as 4–6+, means the set felt easier and you had more reps left in reserve.
How RIR is used in MacroFactor Workouts
RIR helps the app understand how hard each set actually was, not just how many reps you completed or how much weight you used. This allows recommendations to better reflect your true effort and fatigue over time.
You can read more about smart progression here.
Tips for using RIR during training
When starting a new exercise, it may take a few sessions to dial in accurate RIR estimates. Log your weight and give your best estimate rather than worrying about being exact.
It can take time to learn what true technical failure feels like, so do not get frustrated if you need to work up to heavier loads instead of starting there right away.
If a set feels easier or harder than planned, adjust the next set accordingly. Each workout is an opportunity to refine your targets.
RIR does not need to be perfectly precise. Any reasonable estimate is enough for the system to work well.
Additional notes about RIR
Tracking RIR is optional, but it is strongly recommended. It helps the app better account for your current strength levels and how quickly you tend to fatigue. You can learn more about changing RIR during a workout here.
RIR in MacroFactor Workouts is logged on a scale from 0 to 6+. You do not need to estimate beyond that range. If a set felt very easy, selecting 6+ is sufficient.
Read next:
Now that you’ve learned how RIR works, you might enjoy one of these articles next:
Changing RIR During an Active Workout
Understanding and Using Smart Progressions
Why Does the App Sometimes Recommend Lowering Weight or Reps?