Workload Ratio
The Dashboard workload ratio compares the current ATL with CTL from the same TRIMP history.
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 provides background, not a specification of every EffortSignal rule. The formulas, windows, quality gates and examples above describe EffortSignal 0.1.13, checked September 10, 2026. Product-specific thresholds and rounding should not be attributed to the background source.
Content checked September 10, 2026 · EffortSignal release 0.1.13