A subjective scale for measuring exercise intensity. The most common in modern swim coaching is the CR10 / OMNI scale (1-10): 1 = very easy, 10 = all-out. Borg's original RPE scale (6-20) is used in some endurance research but the 1-10 scale is more ergonomic for the pool deck.
RPE naturally supports ranges (RPE 6-7) because actual effort varies lap-to-lap. Single values parse to a degenerate range [n, n].
RPE maps to training zones. The standard mapping (varies by source):
| RPE range | Zone | Description |
|---|---|---|
| RPE 1-3 | Recovery | Very easy, conversational |
| RPE 4-5 | Zone 1 (active recovery) | Easy aerobic, can hold conversation |
| RPE 6-7 | Zone 2 (aerobic threshold) | "Conversational but uncomfortable" (Peter Attia, n.d.) |
| RPE 8-9 | Zone 3-4 (lactate threshold) | Comfortably hard, can speak in short sentences |
| RPE 10 | Zone 5 (VO2 max / all-out) | All-out, cannot speak |
The "conversational pace" test (Peter Attia, n.d.) is a practical zone 2 marker: if you can hold a conversation but it would be uncomfortable, you're in zone 2 / RPE 6-7.
In a swim context:
The coach's challenge: getting the swimmer to a CONSISTENT RPE across sets, so the swimmer can calibrate "this is what RPE 6-7 feels like" and adjust their effort accordingly.
Per the v1.14 plan in RPE nomenclature for Hydrolyze intensity, Hydrolyze will store intensity as RPE (e.g., "RPE6-7" or "RPE10") in:
swimmer_pbs.intensity (the per-(swimmer, stroke, distance, intensity, gear) PB)workout_sets.intensity_label (the workout's target intensity)recorded_times.intensity (the actual intensity of the recorded swim)The parser learns the coach's vocabulary (e.g., "moderate" → RPE6-7) per-coach and saves the mapping for future use.
The pairing engine's accuracy depends on the predictor knowing the swimmer's pace for THE specific intensity. With RPE:
The RPE system makes the confidence calibration tighter and more honest about the actual training intensity vs race intensity.
Published and managed by TARS, an AI co-author built on Nathan's gbrain.