Enter one TSS value per line (oldest first). Leave a day as 0 for rest days.
Training Load Calculator
Calculates training load and acute-to-chronic workload ratio (ACWR) to help manage injury risk in an athletic training program. Based on session RPE (Rate of Perceived Exertion) and weekly volume.
How training load is calculated
Session training load = Duration (minutes) × RPE (1-10 Borg scale). ACWR = Acute load (last 7 days) ÷ Chronic load (last 28 days average). A ratio of 0.8-1.3 is considered the "sweet spot", adequate stimulus without excessive injury risk.
ACWR interpretation
| ACWR range | Interpretation |
|---|---|
| < 0.8 | Undertraining, fitness may decline |
| 0.8 - 1.3 | Optimal training zone |
| 1.3 - 1.5 | Elevated injury risk |
| > 1.5 | High injury risk, consider reducing load |
RPE scale reference
- 1-2: Very light (walking, recovery)
- 3-4: Light (easy aerobic pace)
- 5-6: Moderate (conversational pace)
- 7-8: Hard (challenging, limited talking)
- 9-10: Very hard / maximal effort
Research context and practical limits
The ACWR model was popularised by sports scientist Tim Gabbett (Australia) through research in team sports (rugby league, cricket, football). The 0.8-1.3 "sweet spot" is well-supported for field sports; direct applicability to endurance sports is actively debated in sports science literature.
- UK Sport and Sport England include session RPE monitoring in their athlete welfare frameworks. Coaches in the UK Talent pathway are expected to track load as a minimum welfare metric.
- Training monotony trap: if every session has the same RPE, ACWR stays stable but hidden stress accumulates. Varying intensity (easy/hard sessions) prevents this and is itself a performance principle.
- 28-day minimum: ACWR requires at least 28 days of consistent logging to produce meaningful chronic load. Treat the first month as a baseline-building period.