Session RPE Training Load Calculator
Calculate session training load using the Foster RPE method (RPE × duration).
Foster Session RPE Formula
Session Load (AU) = Session RPE × Duration (min)
Weekly Load = Σ all session loads for the week
Uses the CR-10 scale (0–10). Rate overall session effort 15–30 min post-exercise.
Session Load Reference Guide
| Load (AU) | Category | Typical Session |
|---|---|---|
| < 150 | Very Easy | 30 min walk, mobility |
| 150–300 | Easy | 60 min easy run (RPE 4) |
| 300–500 | Moderate | 60 min aerobic (RPE 6) |
| 500–700 | Hard | 70 min tempo (RPE 7–8) |
| 700–900 | Very Hard | 90 min race pace (RPE 8–9) |
| > 900 | Extreme | Long race / max effort |
CR-10 RPE Scale Reference
| RPE | Description | Feel |
|---|---|---|
| 0 | Rest | Nothing at all |
| 1–2 | Very Easy | Very light, barely moving |
| 3–4 | Easy–Moderate | Comfortable, can talk |
| 5–6 | Moderate–Hard | Hard, breathing heavy |
| 7–8 | Hard–Very Hard | Very hard, can't talk |
| 9–10 | Maximal | Maximum effort |
Frequently Asked Questions
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Session RPE training load = RPE × duration (minutes). Developed by Dr. Carl Foster, it quantifies the internal training stress of any workout. A 60-min run rated RPE 7 = 420 arbitrary units (AU).
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The CR-10 (Category Ratio) scale, rated 0–10. 0 = rest, 5 = hard, 10 = maximal effort. Collected 15–30 minutes after the session for accuracy. Different from the classic 6–20 Borg scale.
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After every session, ask the athlete "How hard was that overall?" using the CR-10 scale. Multiply by session minutes. Track daily and weekly totals to monitor load trends.
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Easy session: 150–300 AU. Moderate: 300–500 AU. Hard: 500–700 AU. Very hard: 700–900 AU. Weekly totals vary by sport: runners 2000–5000 AU, team sport athletes 1500–3500 AU.
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Immediately after exercise, athletes often overestimate or underestimate effort. At 15–30 minutes post-session, perceived exertion stabilizes to better reflect overall internal load.
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Internal load: physiological stress on the athlete (heart rate, RPE). External load: physical work done (distance, speed, power). Session RPE captures internal load regardless of modality.
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Yes. Session RPE works across running, swimming, cycling, weightlifting, team sports, yoga. It captures total body stress regardless of whether GPS or heart rate data is available.
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Sum of all session loads in a week. Weekly load = Σ(RPE × duration) for each session. Track weekly load over time to assess if load is increasing too quickly.
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Rapid week-to-week load increases (>10–15%) are linked to higher injury risk. Monitoring session RPE load trends helps coaches prevent overtraining and injury spikes.
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AU is the unit for session training load from the RPE method. It has no physical dimension but allows comparison across sessions and athletes. Also called "Foster units."
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Studies show session RPE correlates well (r = 0.70–0.85) with heart rate-based TRIMP methods. It is simpler, cheaper, and doesn't require technology.
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Track every training session including warmups and cooldowns if they are separate. Consistency is key — logging all sessions gives accurate weekly and chronic load data.