The Distinction Between 0 RIR and Training to Failure

0 RIR is not the same as training to failure. When you train to 0 RIR, it means you rack the bar when you complete a rep and physically cannot perform another.

Failure is 0 RIR, but 0 RIR is not necessarily failure. This distinction is crucial because training is a balance between stimulus and fatigue. Training to 0 RIR is highly fatiguing, but you can still perform two consecutive sets with similar loads—granted, the second set will either require a lighter load to match the rep count or result in fewer reps if the same load is maintained. However, you can still complete another real and effective working set as long as you don’t actually fail.

Failure—true failure—means you get stapled under the bar. If that happens, you’re not doing another real working set afterward. The cost of that failed set is significantly higher than if you had simply racked the bar at 0 RIR.

For well-trained individuals using high absolute loads, relative loads still matter, but absolute loads likely contribute more to fatigue. If you’re strong and working with heavy weights, pushing a set to failure means you probably won’t be training that movement at high intensity for at least 72 hours—maybe longer. And 72 hours might even be optimistic.

That said, I’m not opposed to failure. I actually think it has its place—but only sparingly.

This also ties into why I don’t program sets beyond 12 reps, and even that is higher than my preference. It’s also why I don’t recommend using loads lighter than 70%, though 70% is likely still too light for my preference. Our ability to gauge RIR declines as the number of reps in a set increases, and as the load gets lighter. (Modeling the repetitions-in-reserve-velocity relationship: A valid method for resistance training monitoring and prescription, and fatigue management, 2024).

This meta-analysis (Accuracy in Predicting Repetitions to Task Failure in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis on RIR prediction accuracy, 2021) found that people are more accurate when predicting RIR in sets of fewer than 12 reps. This is probably because the gradual increase in discomfort over high-rep sets clouds judgment, making it harder to pinpoint the exact moment when you’re nearing failure.

For example, if you use a weight you can only lift for 8 reps, by rep 6, you have a pretty solid idea of how many more you can do. But if you’re working with a weight you can lift for 12 reps, by rep 10, variability in bar speed makes gauging RIR much less precise.

This leads to my final point: if you’re serious about training, velocity-based training (VBT) is a necessity. Get an OVR, get a Vitruve unit—get some objective data. Knowing what bar speed corresponds to your actual RIR is invaluable.

Of course, you still need to be aware of how you feel—your perception matters. A big part of training is experiencing physical hardship and linking psychology with physiology. But as you become stronger and more advanced, precision matters more. Those last few adaptations require a more refined approach. Using objective data like bar speed to align with your perceived final rep in the tank can go a long way in regulating training frequency and recoverability.

If you truly care about training, as I do, the goal is to train as frequently and effectively as possible. I don’t want to leave it all up to guesswork. I don’t want to overshoot and ruin a session two days later, but I also don’t want to sandbag it and leave too much in the tank.