What we're talking about
The ACWR (acute:chronic workload ratio) divides your load over the last ~7 days by your load over the last ~28 days. Put simply: what you're doing right now, relative to what your body is used to.
- Ratio around 1.0: you're doing roughly what your body knows. Healthy adaptation.
- Ratio high: you're suddenly doing far more than usual. This is the breeding ground for overload injuries.
- Ratio low: you're doing much less — detraining, or deliberate recovery.
The zones Baseload reads
Baseload places your ACWR in bands inspired by the load ↔ injury literature. Here's how it interprets them:
| ACWR | Zone | What the coach does |
|---|---|---|
| < 0.8 | Undertraining | Room to rebuild gradually. |
| 0.8 – 1.3 | Optimal | Adaptation window. We hold the course. |
| 1.3 – 1.5 | Caution | We ease back the volume of upcoming sessions (~ −15 %). |
| > 1.5 | Danger | We switch to easy sessions; today's hard session is downgraded. |
The coach triggers an early warning from ~1.2, even before the caution zone — the goal is to warn you while it's still easy to adjust, not once the slope is already too steep. Above 2.0, the increase is so abrupt that the coach imposes rest.
The classic trap: after a rest day or a break, you feel fresh and you start back too hard. The ACWR sees that step up that feel doesn't, and the coach suggests a gentler ramp — the one that lets you progress and last.
A compass, not a verdict
The ACWR describes population trends, observed across large groups of athletes — not a prediction about you specifically. A ratio in the optimal zone doesn't guarantee you won't get injured, and a one-off high ratio isn't a foregone conclusion. Baseload uses it as a compass to steer the decision, always cross-checking it with your recovery and your per-muscle-group fatigue.
The ACWR model is debated in research, and it's sensitive to the way load is computed. Baseload takes it for what it is : a useful anti-runaway guardrail, not an exact physiological law. See Our model, its limits.