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What is RIR (reps in reserve) in lifting?

RIR (reps in reserve) is how many more clean reps you could have done when you ended a set. RIR 2 means about two left. Here's how to judge it.

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The short answer

Reps in reserve (RIR) is how many more clean reps you could have done when you ended a set: RIR 2 means you stopped with about two left, RIR 0 means you had nothing left. Lifters use it to set how hard each set should be without training to failure.

Reps in reserve (RIR) counts the clean reps left when you end a set, so two left is RIR 2. A 2022 meta-analysis suggests the average guess runs about one rep short (Halperin et al., 2022).

What is RIR (reps in reserve) in lifting?

  • 0: no clean rep left (the "Failure" chip in Orion Coach).
  • 1 to 3: that many left.
  • 4+: easy.

RPE is roughly 10 minus RIR, so RPE 8 is about RIR 2 (Helms et al., 2016).

How do you estimate RIR during a set?

Judge it over your last 2 or 3 reps: slowing reps, harder bracing and slipping form mean you're close. Slower bar speed on heavier single squat reps was associated with higher effort ratings (Zourdos et al., 2016).

Coach Orion's call

I ask for an RIR on every working set: how many more clean reps you could have done when you stopped. You tap 0 "Failure", 1, 2, 3 or "4+ Easy". My 0 means no more reps with good form. That stops a little short of the "weight won't move" failure many studies use.

The target tells you where to stop: mostly 2 reps in reserve, sometimes 3 or 1, never 0. Sets taken to failure can drag down the sets after them, and they blur my read of whether you're strong or just fried. Warm-ups sit at 5 and deload weeks at 3.

The number you log tells me how hard that set really was. I compare it with the target and adjust your next set by no more than one step, and double progression covers what that step is. That's how I run rep ranges for intermediate and advanced lifters; beginners and top-set barbell programs follow their own rules.

On a rough recovery day I raise the target instead of cutting your weight: 1 more rep in reserve when you're a little off, 2 when you're clearly off.

Your guess will sometimes be off by a rep. A one-rep miss changes your next set by no more than one step, not your program.

Worked example

A walkthrough of how Orion applies this rule, not a real user's data.

  • Starting state: DB Skull Crushers, 20 lb per hand, rep range 10 to 14, target RIR 3 (Orion Coach's Strength + Hypertrophy 4-day Intermediate program). RIR 3 means each set ends with about 3 clean reps still in you.
  • Set 1: 12 reps at 20 lb. You could have done about 3 more with good form, so you tap 3. That's right on target.
  • Set 2: 13 reps at 20 lb. The last two reps slow down noticeably, and about 2 clean reps were left. You tap 2, one rep harder than the target.
  • Set 3: 13 reps at 20 lb, and a 14th wouldn't have been clean. You tap 0 "Failure", 3 reps harder than the target and a set I never program on purpose.
  • If a set had left you 4 or more clean reps, you'd tap "4+ Easy": more in reserve than the target asks for.
  • What I do with each of those numbers next is the double progression rule.

What the evidence doesn't tell us

The one-rep guessing gap averages 12 studies that varied enormously (Halperin et al., 2022). The scale and reliability studies used younger lifters on barbell lifts (Zourdos et al., 2016; Lovegrove et al., 2022), not lifters over 40 with dumbbells.

Frequently asked questions

Does RIR 0 mean the weight won't move at all?
Not in Orion Coach. Its RIR 0 means you couldn't have done another rep with good form, which stops a little short of the "weight won't move" failure many studies use. Researchers don't all define failure the same way (Steele et al., 2017).
What if my RIR guess is off by a rep?
That's normal. A 2022 meta-analysis suggests lifters guess about one rep short on average, so they usually have a little more left than they think (Halperin et al., 2022). In Orion Coach, a one-rep miss changes your next set by no more than one step, not your program.
Should warm-up sets have an RIR?
Yes, a high one. Orion Coach sets warm-ups at RIR 5 so they prepare you for your working sets without tiring you.
Does RIR work with light dumbbells at home?
With a fixed weight, RIR is the main way Orion Coach can tell whether a set was hard enough, so it's useful there. Expect it to be harder to judge: the meta-analysis suggests guesses are less accurate on sets of more than 12 reps (Halperin et al., 2022), and we didn't find a study that tested RIR in home dumbbell training.
Why would my target RIR go up on some days?
In Orion Coach, a rough recovery read, such as HRV well below your average or a low Body Battery you type in from your Garmin, can add 1 or 2 reps in reserve to the target. It doesn't lower the weight.

Sources

  1. Zourdos MC, Klemp A, Dolan C, et al. (2016). Novel Resistance Training-Specific Rating of Perceived Exertion Scale Measuring Repetitions in Reserve. Journal of Strength and Conditioning Research.
  2. Helms ER, Cronin J, Storey A, et al. (2016). Application of the Repetitions in Reserve-Based Rating of Perceived Exertion Scale for Resistance Training. Strength and Conditioning Journal.
  3. Halperin I, Malleron T, Har-Nir I, et al. (2022). Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis. Sports Medicine.
  4. Lovegrove S, Hughes LJ, Mansfield SK, et al. (2022). Repetitions in Reserve Is a Reliable Tool for Prescribing Resistance Training Load. Journal of Strength and Conditioning Research.
  5. Steele J, Fisher J, Giessing J, et al. (2017). Clarity in reporting terminology and definitions of set endpoints in resistance training. Muscle & Nerve.

Related reading

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