Training Load Calculator
Calculate your weekly training load using session RPE (sRPE).
Track acute and chronic load to find the sweet spot between fitness and injury risk.
Training load quantifies how much stress your body experiences from exercise. The most practical method is Session RPE (sRPE), developed by Dr. Carl Foster: multiply the session duration (minutes) by the perceived exertion (RPE on a 1–10 scale). The result is in arbitrary units (AU).
The sRPE formula: Session Load = Duration (minutes) × RPE (1–10)
RPE scale reference:
- 1–2: Very easy (warm-up, walking)
- 3–4: Easy (easy run, light swim)
- 5–6: Moderate (tempo, steady-state)
- 7–8: Hard (threshold, intense intervals)
- 9–10: Maximum (race effort, all-out)
Example: A 60-minute run at RPE 7 = 60 × 7 = 420 AU.
Acute:Chronic Workload Ratio (ACWR): Acute load is your last 7 days of training. Chronic load is your average over the past 28 days (or 4 weeks). The ACWR = Acute Load / Chronic Load.
Research suggests:
- ACWR 0.8–1.3: Sweet spot — optimal training stimulus, low injury risk
- ACWR < 0.8: Undertraining — fitness may decline
- ACWR > 1.3: Danger zone — significantly increased injury risk
- ACWR > 1.5: High risk — sharply elevated injury probability
Practical guidance: Increase your weekly training load by no more than 10% per week. After a hard training block, include a recovery week at 60–70% of your peak load. This periodisation approach maximises fitness gains while minimising injury risk.