RPE vs. RIR: The No-Nonsense Way to Gauge Your Effort in the Gym
As strength training has evolved, many lifters have moved away from rigid percentage-based programs toward systems that adjust effort based on how workouts actually feel. Two of the most common tools used to guide that approach are RPE (Rating of Perceived Exertion) and RIR (Reps in Reserve). Both methods help you estimate how close you are to your limit during a set, allowing training intensity to adjust to your daily readiness rather than forcing predetermined numbers.
At their core, both systems measure proximity to failure. In other words, they help answer the same fundamental question: How hard was that set, really? The difference is simply how that effort is described. RPE focuses on the overall difficulty of a set, while RIR focuses on how many repetitions you could still perform before reaching failure. Here’s how the two systems compare.
Related: How to Do Jump Squats the Right Way for More Power, Speed, and Explosive Strength
RPE (Rating of Perceived Exertion)
- What it measures: Overall effort of a set using a 1 to 10 scale.
- How it works: The higher the number, the harder the set feels.
- Key question:How difficult did that set feel?
- RPE 10: Maximum effort with no reps left in the tank.
- RPE 8 to 9: Challenging work that stops just short of failure.
- Where it shines: Works across many training styles, including strength work, higher rep training, and conditioning.
RPE has become increasingly popular in modern training programs because it reflects the reality that performance fluctuates. Sleep, stress, and recovery can all influence how heavy a given weight feels on any particular day.
RIR (Reps in Reserve)
- What it measures: How many repetitions you could still perform before reaching failure.
- How it works: Lower numbers mean the set was closer to your limit.
- Key question:How many more reps could I have done?
- 0 RIR: No reps left. You reached failure.
- 1 to 2 RIR: Very challenging sets that stop just short of failure.
- Where it shines: Often used in hypertrophy-focused training and moderate rep strength work.
Because RIR focuses directly on remaining repetitions, many lifters find it intuitive when working with traditional sets of 6 to 12 reps, where estimating additional reps is easier.
The Cheat Sheet: RPE vs RIR
| Effort Level | RPE (1-10) | RIR (Reps Left) | How It Feels |
|---|---|---|---|
Max Effort | 10 | 0 | Absolutely zero reps left. |
Very Hard | 9 | 1 | Could have done maybe one more. |
Challenging | 8 | 2 | You're working hard, but form is perfect. |
Moderate | 7 | 3 | Solid work; definitely had a few more. |
Quick Programming Tip: Using RPE and RIR Week to Week
Both RPE and RIR can help structure a training block by gradually increasing intensity over several weeks. Instead of pushing to failure every workout, the goal is to slowly move closer to your limit as the training phase progresses.
A simple four-week progression might look like this:
- Week 1: RPE 6 to 7 or about 3 to 4 reps in reserve. Focus on clean technique and establishing a baseline weight.
- Week 2: RPE 7 to 8 or about 2 to 3 reps in reserve. Increase the load slightly while keeping most sets repeatable.
- Week 3: RPE 8 to 9 or about 1 to 2 reps in reserve. Training becomes more challenging and intensity climbs.
- Week 4: RPE 9 to 10 or 0 to 1 reps in reserve. Include your heaviest work of the cycle before backing off for the next phase.
Both RPE and RIR are tools designed to help lifters train with more awareness. Instead of relying solely on fixed percentages, they encourage you to adjust effort based on how your body responds during a workout. Whether you prefer to rate the overall difficulty of a set or estimate how many reps remain, the goal is the same: apply the right amount of effort to stimulate progress while managing fatigue.
Related: The Right Way to Train Around Shoulder Pain, According to Experts