Training Load Acute:Chronic Ratio (ACWR)

AC:WR = 7-day training load / 28-day average. Sweet spot 0.8-1.3; >1.5 raises injury risk.

Inputs

Sum your weekly TSS, mileage, lifting tonnage, or RPE×duration.

Sum of last 28 days ÷ 4.

Result

AC:WR
1.25
✓ Sweet spot (low injury risk)
  • Acute load (7d)1,500
  • Chronic load (28d avg)1,200
  • Ratio1.25
  • Zone✓ Sweet spot (low injury risk)
  • Sweet spot0.80 – 1.30
  • Over-spike threshold> 1.50

Step-by-step

  1. AC:WR = acute / chronic = 1,500 / 1,200 = 1.25.
  2. Maintain or progress 5-10%.

How to use this calculator

  • Track a load metric daily for ≥4 weeks.
  • Sum last 7 days = acute.
  • Sum last 28 days ÷ 4 = chronic.
  • Aim for AC:WR 0.8-1.3.

About this calculator

The Acute:Chronic Workload Ratio (Gabbett 2016) compares the past 7 days of training to the rolling 28-day average. Ratio between 0.8-1.3 = "sweet spot" with the lowest injury risk. >1.5 ("spike") is associated with 2-4× the soft-tissue injury rate in team sports. <0.8 means undertraining or detraining — safe but slower adaptation. Use any consistent load metric: cycling TSS, running mileage, RPE × minutes, or lifting tonnage. Recalculate weekly.

Frequently asked

Anything consistent: TSS, mileage, RPE × duration, swim yardage, lifting tonnage. Don't mix metrics within the same calculation.

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