Training load expresses how much physiological stress a session imposes, so you can compare an easy 10K against a hard interval workout on a single scale.
Acute vs. chronic load
Runima's ACWR compares two windows of training stress:
| Term | Window | Meaning |
|---|---|---|
| Acute load | 7 days | Recent total training stress. |
| Chronic load | 28 days | Average weekly stress over four weeks. |
The ratio between them (acute ÷ chronic) is the acute:chronic workload ratio (ACWR). It describes recent load relative to your usual load; it is not a validated injury predictor or readiness test.
ACWR = last 7 days' TSS / (last 28 days' TSS / 4)
< 0.8 below usual load
0.8–1.0 light load
1.0–1.3 near usual load
1.3–1.5 above usual load
> 1.5 well above usual load
Session-distance comparisons
Runima compares each proposed session with the longest completed run in its preceding 30-day window. A large observational running study associated increases above 10% with higher overuse-injury rates. This does not estimate your personal injury probability, and staying below the reference does not guarantee safety.
Generated plans do not have scheduled session dates, so comparisons use the week's start, or today for the current week. Coach-authored plans use scheduled workout days. Planned runs never count as completed history; comparisons can become unavailable when existing history expires.
For generated plans, you can explicitly choose a fixed session-distance ceiling.
Runima reduces the weekly session mix and recalculates running load and fitness projections. Changing an active plan's ceiling enables auto-adjust. The ceiling remains a chosen planning limit until changed or removed; it is not a rolling safety limit. Coach-authored workouts receive warnings without being rewritten.
Weekly growth percentages, recovery factors, block structures, ramp cutoffs, and gentler loading presets are coaching assumptions rather than validated injury-prevention or rehabilitation protocols.