Acute:chronic load ratio
Your last week's training load compared with the weeks before it. A soft hint that you've ramped up fast, never a prediction.
The ratio divides your acute training load (about the last 7 days) by your chronic load (about the last 28). Around 1 means this week looks like your recent weeks. Higher means you've stepped things up.
When the ratio reaches about 1.5 on any of the last 3 days, Pajdo may say you ramped up fast. He waits until 28 days after your first workout so the longer average has something to stand on, and he trusts it less when many recent workouts had no heart rate.
It's a hint, not a forecast. The ratio became popular in sport as a way to predict injuries, but a critical review found no evidence that supports using it for that: as a number it's inaccurate and adds noise, and no study has shown that steering it changes injury rates. The better-supported advice is simpler. The WHO recommends increasing how often, how hard and how long you're active gradually over time.
What tends to push it up
- A big week after a few quiet ones
- Coming back after a break
What tends to pull it down
- Easy days or rest days after a big week
Keep reading
Sources
- Acute:Chronic Workload Ratio: Conceptual Issues and Fundamental Pitfalls (Impellizzeri et al. 2020), International Journal of Sports Physiology and Performance
- World Health Organization 2020 guidelines on physical activity and sedentary behaviour (Bull et al. 2020), British Journal of Sports Medicine
Checked against these sources on September 15, 2026.
This is general wellness information, not medical advice. If a number worries you, or stays away from your usual for a while, talk to a doctor.