Depending on who you ask, Reps in Reserve can be a science-backed way to train hard without cutting into your recovery, or a spreadsheet-driven excuse to avoid training hard.
So, which is it?
If you’ve ever finished a set and thought, “I probably had two more reps left in the tank,” That’s RIR in a nutshell. The concept is solid: instead of treating every set like all-out war, you stop a rep or two short and use those reps left in the tank to manage fatigue, volume, and long-term gains.
But the trouble arises when it’s left open to interpretation.
Some lifters use RIR as an autoregulation tool, while others treat it as a comfort blanket, convincing themselves they’re training hard when they’re nowhere near it.
Here, we try to break down what RIR is, why some and others defend it, why critics are slamming it, and, most importantly, whether RIR is helping or hurting your gains.
RIR Origins
Reps in Reserve (RIR) emerged from exercise science research in the early 2000s, particularly studies on Rating of Perceived Exertion (RPE). Popularized in endurance sports, RPE was adapted to strength training to gauge how hard a set felt by the number of reps you had left in the tank.
RIR, a strength-specific spin-off of RPE, was refined and popularized by evidence-based training leaders such as Dr. Mike Tuchscherer and, later, Dr. Mike Israetel. Israetel’s take went viral because it blended periodization, hypertrophy science, and autoregulation—the idea that you can adjust training intensity based on how your body feels and performs, rather than chasing numbers.
But what began as a self-regulation tool for intermediate to advanced lifters somehow became social media shorthand for “don’t train too hard,” especially when it came to more inexperienced lifters. Many influencers began preaching RIR like gospel without explaining how to gauge it or when to use it. As expected, the backlash followed.
In short, the concept was solid. The execution? It hasn’t always gone as planned.
What Is Reps in Reserve (RIR) in Strength Training?
Reps in reserve is a self-assessment tool that estimates how many more quality reps you can do in a set before technical failure. Technical failure is when you cannot perform another full-range-of-motion rep with good form. So, if you bench 225 for 8 reps and feel like you have 2 more reps in the tank, that’s RIR 2. It’s a way to auto-regulate effort based on how you feel that day—instrumental when you’re juggling stress, sleep, and recovery. RIR helps manage fatigue while ensuring you’re still training with sufficient intensity.
Here is what RIR shouldn’t be used for
- RIR doesn’t mean stopping just because it’s hard.
- It’s not a license to never grind.
- And it’s definitely not a substitute for effort.
If you’re saying a set was RIR 2, but you could’ve cranked out 5 more reps… you’re misjudging your effort and not using RIR. It works best when you’re honest with yourself and have put in enough time under the bar to feel the difference between hard and near-failure.
How to Use RIR Correctly Without Killing Your Gains
Reps in Reserve, when used correctly, balance your gains and recovery from training. It lets you flirt with failure without smashing into it, which helps with progress, recovery, and longevity. But using RIR requires self-awareness, effort, and honesty. Yes, it will take time if you’re new to it and you need to know what lifting to failure feels like before deciding if you have a rep or two in the tank.
Experience is your greatest teacher here. To make this practical, here’s a visual guide:
How to Apply RIR
Sample RIR Guide
Goal
Exercise Type
RIR Target
Why
Max Strength
Compound Lifts
1-2 RIR
Maintains bar Speed and form under heavy loads without grinding
Hypertrophy (Size Gains)
Compound & Isolation
0-2 RIR
Tension + Proximity to failure triggers growth stimulus
Muscular Endurance
High-Rep Movements
1-3 RIR
Preserves form while managing fatigue
Skill/Technique Work
Olympia Lifts,Complex Moves
3-4 RIR
Prioritizes movement quality over effort
What the Science Actually Says About RIR and Gains
RIR Is a Reliable Tool for Recommending Load
A study published in the Journal of Strength and Conditioning Research found that RIR is a reliable method for recommending load for exercises such as the deadlift and bench press. When trained lifters use RIR consistently, it aligns with actual intensity, making it useful for autoregulating training.
RIR Reflects How Close You Are to Failure
Research on RPE scales tied to RIR shows that lifters’ subjective estimates of how many reps they have left do correspond to meaningful differences in training intensity, especially as lifters gain experience with the system.
RIR Accuracy Improves With Experience
One criticism of RIR is that lifters can’t judge how many reps they have left. The evidence is mixed but promising: experienced lifters tend to be reasonably accurate at estimating RIR, especially near failure, whereas beginners tend to be conservative.
Proximity to Failure and Gains
Several studies have examined how close to failure you train, the core premise of RIR, and how it affects muscle and strength: An intervention comparing sets taken to failure with sets stopped a few reps shy found that muscle size and strength gains were similar when training near failure. This study suggests that going all-out every set isn’t required for gains. Research manipulating RIR zones (e.g., 1–3 RIR vs. 4–6 RIR) found comparable strength gains between zones and similar gains when training to actual failure. This study supports the idea that stopping shy of failure can maintain growth while reducing extreme fatigue. A dose–response review points toward more growth when sets get closer to failure, but researchers still haven’t nailed down the exact RIR–hypertrophy relationship
So, why is RIR being taken to task?
Why Some Lifters Say RIR Is ‘Lazy Training’
Reps in Reserve isn’t under fire because it doesn’t work—it’s under fire because it’s sometimes misinterpreted and treated as a free pass to ease up. Here’s what the naysayers have to say.
RIR Turns Into ‘Lazy Training’
Some coaches argue that RIR encourages undertraining. The logic? If you always leave 3–4 reps in the tank, you might never reach the effort threshold needed for gains, especially if you’re not honest with yourself. Critics like Jeff Nippard have warned that too much RIR can turn into sandbagging. This line of thinking has led to the other extreme of “Just go to failure every time and forget the numbers.” But that creates its own problems: burnout, poor recovery, and plateauing.
Where the Confusion Exists
Recently, Dr. Mike Israetel, a long-time advocate of RIR-based training, helped popularize this system by giving lifters a framework to regulate intensity across training blocks. But now, even some experts and followers and content creators have questioned how rigid or over-intellectualized the RIR method has become when applied by less-experienced lifters.
His approach has been successful for many RP Strength users and RIR proponents. The other side of the argument appears when it comes to less experienced lifters.
- Don’t know what failure actually feels like
- Overestimate how hard you’re pushing
- Stay in a high RIR zone forever and call it “smart training.
Some coaches now argue that lifters should learn RIR only after they develop a solid kinesthetic sense of actual failure, not before. This argument makes a lot of sense.
N1 vs. RP
Kassem Hanson from N1 Training, who’s challenged Israetel and RP’s hypertrophy approach in recent months. The feud has stirred controversy across YouTube, Instagram, and podcasts.
Kassem argues that:
- RIR and volume targets are overrated without proper exercise selection
- Lifting form, joint angles, and biomechanics matter more than chasing reps and proximity to failure
- Many lifters following RIR templates don’t know how to contract muscles or control tempo—so the effort metric becomes meaningless
This clash has reignited a bigger discussion in the lifting world:
What’s more important: data or context? Science or execution? Templates or tailored coaching? Neither side is wrong, but this debate is a reminder: frameworks aren’t infallible, and coaching nuance trumps spreadsheets.
Bottom Line for Men Focused on Strength, Recovery, and Longevity
Reps in reserve is a legit, science-backed method for gauging effort and managing fatigue without grinding yourself into dust. It’s not perfect, and it’s not for everyone, but it’s far from
useless. What kills gains isn’t RIR; it’s not training hard enough while pretending that you are.
RIR’s biggest critics often haven’t tried it, misinterpret it, or have misused it. If your idea of “leaving 3 reps in the tank” means stopping when your biceps tingle, you’re missing the point. Before you slam RIR, give it a shot first.
Train hard. Recover smart and don’t be afraid to try it before tossing it aside.
