What is a good ACWR for runners?

An Acute:Chronic Workload Ratio between 0.80 and 1.30 is the sweet spot, carrying the lowest injury risk. Above 1.50, injury risk rises 2 to 4 fold.

How many weeks do I need to enter?

At minimum, this week and last week. Entering all 4 prior weeks gives a more stable chronic load and a more reliable ratio.

Is ACWR better than the 10% rule?

ACWR accounts for how big a jump is relative to your recent training, not just the raw percentage. It is the load-management standard in sports science, while the 10% rule is a fixed cap that is often too conservative.

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Training · Calculator

Acute:Chronic Workload Ratio Calculator for Runners

Enter this week's mileage plus your recent weeks to see your ACWR, your injury-risk zone, and the safe mileage ceiling for the week ahead. Fill all 4 prior weeks for the most accurate chronic load.

Enter this week and at least one prior week to see your ACWR and safe ceiling.

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