Running load checker
Most running niggles follow a sudden jump in training. Put in this week and your last four, in miles, kilometres or minutes, and see how today compares with normal.
Your details
This week compared with your usual
1.50
A step up (ratio to your four week average)
- This week30.0
- Four week average20.0
- Change from last week+36%: over the 30% jump linked with more injuries in new runners
- Most for next week at a 1.3 ratio29.9 (against 23.0 once this week counts)
- Next weekadd what you plan to see its ratio
A bit more than usual. Fine now and then; keep the next week steady. This is a rough guide from sports science studies, not a prediction that you will or will not get injured.
Pain that changes how you run, swelling, or pain at night: stop running and see a GP or physio.
The working
Acute against chronic
Your four week average of 22, 20, 20 and 18 is 20. This week's 30 divided by 20 is a ratio of 1.50: right on the edge of a big jump. Between 0.8 and 1.3 is the steady zone where most people adapt well.
Next week
Planning the step
Once this week counts, the four weeks are 30, 22, 20 and 20, an average of 23, so staying at a 1.3 ratio means no more than 29.9 next week; a planned 25 is a steady 1.09. The weighted option (Williams and colleagues, 2017) lets recent weeks count more: from 18, 20, 20 and 22 it gives a usual load of 20.4 and a ratio of 1.47.
The bands
What the ratio means
| Ratio | Reading |
|---|---|
| under 0.8 | lighter than usual |
| 0.8 to 1.3 | steady |
| 1.3 to 1.5 | a step up |
| over 1.5 | a big jump |
The evidence
How sure is this?
Gabbett's 2016 review popularised the ratio, and a Danish study of new runners found more injuries after weekly jumps over 30%. Later papers have argued over the exact maths, so treat it as a nudge to build gradually rather than a risk score.
Read with care
What this cannot tell you
- Injury predictionIt cannot say whether you will get hurt.
- IntensityTen fast miles load you more than ten easy ones.
- Life stressPoor sleep and stress lower what you can handle.
Questions
Common questions
What is the acute to chronic workload ratio?
This week's load divided by your average over the last four weeks.
How much can I increase my running safely?
Gradually, staying under about 30% in any one week.
Can I use minutes instead of miles?
Yes. Just use the same unit for every week.
Sources
- Gabbett TJ. The training injury prevention paradox. Br J Sports Med 2016
- Nielsen RO et al. Excessive progression in weekly running distance and risk of running related injuries. J Orthop Sports Phys Ther 2014
- Buist I et al. No effect of a graded training program on running related injuries in novice runners. Am J Sports Med 2008
- Williams S et al. Better way to determine the acute:chronic workload ratio? Br J Sports Med 2017
Last checked 21 October 2026. Spotted something wrong? Tell us and we will fix it.
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