RIR is essentially how many reps you have in the tank with GOOD technique before hitting failure. Generally speaking, research has found that anything around 3 or less reps in reserve (3 RIR) is optimal for hypertrophy.
Gauging RIR is important to show us how hard we’re training, which is super important to dictate whether your training intensity and effort needs to be improved. If we aren’t training hard enough, e.g 6 RIR, we cannot maximise gains.
Research has found that particularly among beginners, RIR is grossly underestimated. One study found that when the beginner perceived themselves to be at 1RIR, after verbal encouragement and motivation from the testers, they did 5, some even 10 more reps.
On the contrary, without gauging RIR, you may subsequently be going too hard. If we can’t tell 3RIR or 0RIR apart, you risk training too close to failure weekly, accumulating lots of fatigue and stalling out rapidly (even starting to regress - as I did this mesocycle lol xxxx).
You don't want to be pushing TOO hard to the point that you’re unable to recover and continue to progressively overload!
People differ greatly in how 3RIR feels. On average, we can gauge RIR by noticing the…
Speed of the lift. Around 3 RIR - it will massively slow down
Lactic acid in the muscle will ramp up the burn GREATLY
A high focus is required to keep good technique
You will feel a bit weaker towards the end of the reps, like the bar is pushing back against you.
0 RIR occurs when you’re pretty sure the rep next won't make it/you’ll fail. This last rep of a 0RIR set will seem like it takes EVERYTHING out of you. It's best to avoid 0RIR on compound movements for safety reasons - particularly without a spotter.
In addition to this, if you have no clue of your RIR - you may be training to 0 RIR one week and 3 RIR the other! It helps with autoregulation and consistency - ensuring that from week to week you are progressing with the same factors applied.
Here's a helpful RIR chart from Revive Stronger!
