RPE Information
NSEA Swim · Coaching Reference
RPE & Session-RPE
A working guide to rating perceived exertion and turning it into a trackable training-load number — with the breakpoints that are specific to swimming.
1 What RPE is
Rate of Perceived Exertion (RPE) is a swimmer's own read on how hard something felt — muscles, lungs, and mental fatigue rolled into one number. It needs no equipment, and it catches what a pace clock can't: heat, poor sleep, travel, or illness all raise perceived effort at a pace that used to feel easy.
Two scales are in use. The original Borg 6–20 scale is built so the rating × 10 roughly approximates heart rate (13 ≈ 130 bpm) — it's the standard in most published research. Most coaches and athlete apps now default to the simpler CR-10 scale below, because its spacing better matches how effort actually feels as it climbs.
2 Session-RPE: the load formula
Session-RPE (Foster et al.) turns one post-practice number into a training-load figure for the whole session — comparable across a technique swim, a race-pace set, or a dryland session.
Collect one overall rating 15–30 minutes after practice ends — not mid-set — so the number reflects the whole session rather than however the last five minutes felt. Logged consistently across a squad, this builds a simple per-athlete load history that flags a spike or a flat week without any equipment beyond a whiteboard or a text.
3 Swimming's RPE zones run differently
Research on elite open-water swimmers found perceived-exertion breakpoints for lactate threshold that don't match land-based endurance sports — water resistance rises exponentially with speed, which widens the middle zone.
Below the first lactate threshold. Aerobic base work, ~1.2–1.3 mmol/L lactate.
Between LT1 and LT2 — a wider band than in running or cycling. ~1.7–3.0 mmol/L lactate.
At or above the second lactate threshold. Race-pace and above, ~4.0+ mmol/L lactate.
Because pace and RPE can decouple in the pool — technique, taper state, or even pool speed all shift the relationship — sRPE is a useful cross-check on intended zones. A set built as "moderate aerobic" that keeps coming back at RPE 7+ is worth a second look, either at the pacing target or the athlete's readiness.
4 Using it week to week
- ✓ Total load — sum daily AU across a week or block and compare against the plan's intended trend.
- ✓ Load ratio — a rolling week vs. a rolling 4-week average; a sharp spike is one signal worth a look, not a hard stop rule on its own.
- ✓ Monotony — near-identical daily loads combined with high total load has been linked to higher injury/illness risk in other sports.
- ✓ Collection habit — one number per athlete, 15–30 min post-practice, logged the same way every day so the trend stays comparable.
Sources
- Session-RPE Method for Training Load Monitoring: Validity, Ecological Usefulness, and Influencing Factors — Frontiers in Physiology, 2017
- Session RPE Breakpoints Corresponding to Intensity Thresholds in Elite Open Water Swimmers — PMC
- Using Session-RPE to Monitor Training Load in Swimmers — Strength & Conditioning Journal, 2008
- RPE Scale: The Complete Guide to Rating Perceived Exertion — TrainingZones
- Borg Rating Scale of Perceived Exertion — Shirley Ryan AbilityLab