Use RPE to set strength training load instead of fixed percentages

An RPE 8 on a squat means two reps left in the tank — this calibrates load to your actual state on that day.

Why it works

Traditional percentage-based strength programming (e.g., 3 sets at 80% of 1RM) assumes your 1RM is constant, which it is not. Variations of 5–10% in day-to-day 1RM are normal based on recovery, sleep, and stress. RPE-based loading accounts for this: an RPE 8 set always means approximately 2 reps in reserve (RIR), regardless of the absolute weight, so the stimulus is calibrated to your actual physiological state.

How to do it

1. Define your target RPE for the session (e.g., RPE 7–8 for hypertrophy work, RPE 9–10 for max strength).
2. Select a weight and complete the set; rate the RPE immediately after.
3. Adjust the next set up or down to land in the target RPE range.
4. Log the RPE alongside the weight and reps — this becomes your programming data.

Evidence

The RIR-based RPE framework for resistance training was developed and validated by sports scientist Mike Zourdos and colleagues, showing good accuracy for predicting reps in reserve. (observational)

RPE accuracy for strength work improves with practice; novice lifters systematically underestimate reps remaining, making RPE-based programming less reliable early in training.

Sources

• Zourdos et al. (2016), modified RPE scale for resistance training, Journal of Strength and Conditioning Research

Common mistake

Conflating RPE with effort level or motivation — an RPE 6 on a deadlift is not "being lazy," it means four reps were genuinely available, which is the correct output for a deload session.