Workload Ratio
The Dashboard workload ratio compares the current ATL with CTL from the same TRIMP history.
The ACWR (Acute:Chronic Workload Ratio) guide shows the Dashboard graph, ratio help, Calendar and Week Details, with a worked training week and a lighter week.
Formula and bands
Workload ratio = ATL / CTLThe ratio is dimensionless and uses the selected day’s updated ATL and CTL. The product bands split at 0.8, 1.3 and 1.5: below 0.8; 0.8 through 1.3 inclusive; above 1.3 through 1.5 inclusive; and above 1.5. These product classifications are not validated medical probabilities. Nonpositive CTL makes the ratio unavailable; two zeros do not become a ratio of one.
Verified example
ATL 60 and CTL 50 give 1.20. ATL 65 with CTL 50 gives exactly 1.30, still in the inclusive middle band. With CTL zero, the API returns an unavailable value instead of infinity.
The neighboring fatigue band is different
The recommended ATL band is 0.8 × CTL through 1.4 × CTL and needs at least 14 days of history plus positive CTL. For CTL 50, that is 40–70. Its upper multiplier 1.4 is intentionally not the ratio-classification boundary 1.3.
The ratio inherits training-load history limitations. It is also different from the uncoupled seven-day versus previous-five-week workload ratio used inside Readiness. Neither can establish an injury prediction from this number alone.
Sources and implementation scope
Bourdon and colleagues (2017), monitoring athlete training loads explains the research background. The formulas, windows, quality gates and examples above describe EffortSignal 0.1.25, checked September 14, 2026. Thresholds and rounding are EffortSignal rules.
Content checked September 14, 2026 · EffortSignal release 0.1.13