Core Idea: Reps in Reserve (RIR)
Reps in Reserve (RIR) is a measure of how hard you've taken a set â i.e., how many repetitions you still have left before reaching mechanical muscular failure.
- 0 RIR: You've taken the set to full mechanical failure â no more reps possible in good form.
- 1 RIR: You could probably grind out one more rep if you really had to.
- 2â3 RIR: You still have one or two reps left in the tank, but the set is already demanding.
- 4+ RIR: For Jeff, this already becomes junk volume â except for warm-up sets.
The Problem: Perceiving Effort Accurately
Most people â even trainers â underestimate what they're capable of by about one to three reps. If you don't have a clear sense of what 0 RIR feels like, it's very hard to gauge the subtle difference between 1, 2, or 3 RIR.
The Solution: Train Close to Mechanical Failure
Jeff recommends taking most sets as close to mechanical failure as possible. He distinguishes between:
- Psychological failure: You could physically do another rep, but you're not willing to tolerate the discomfort.
- Form failure: The rep gets slower or slightly looser â that's acceptable as long as you stay in control.
- Joint pain: This is an absolute stop signal. If you feel joint pain at any point, stop immediately.
Important Distinction: Good Form Failure vs. Sloppy Reps
It's not about ugly, unstable repetitions. It's about good form failure: you push to the point where the exercise can't physically be completed â without cheating or losing body stability.
Takeaway
By regularly training with real intensity up to form failure, you can reduce training volume, protect your joints, and achieve better results through higher intensity. The objective signal âI can't move this weight anymoreâ helps you eliminate junk volume and dramatically improve training quality.