Weekly distance, four-week means, and jump markersLive current inputs
Health & Fitness
Running Training Trend Calculator
Analyze eight weeks of running distance for direction, variability, largest jump, four-week acute-to-chronic comparison, and consistency without treating a workload ratio as an injury prediction.
Eight-week mean —
Weekly trend —
Week-to-week variability —
Largest one-week increase —
Latest four-week mean —
Earlier four-week mean —
Latest/earlier four-week ratio —
Descriptive status —
Eight-week workload river
Weekly distance, four-week means, and jump markers
The area trace shows volume direction, while distinct markers identify week-to-week increases instead of hiding them inside one ratio.
Weekly trend ledger
Distance, change, moving average, and sequence role
Each week remains visible so a ratio cannot obscure which observation created the apparent change.
| Week | Distance | Change | Change % | 4-week mean | Sequence note |
|---|
Trend setup
Enter complete weeks using one distance definition
- Use the same week boundary and device rules for all eight values.
- Include zeros for true no-running weeks rather than deleting them.
- Review intensity, terrain, duration, and pain beside distance.
- Inspect the week that created the largest jump.
- Use the ratio as a description of change, never as a safety guarantee.
Why show the raw weeks
A ratio can hide the story that produced it
The same latest-to-earlier ratio can arise from steady progression, a single spike, or a reduced comparison block. The chart and ledger preserve the sequence.
Distance is only one external-load measure. Faster pace, hills, technical terrain, and harder sessions can increase demand without increasing kilometres.
Descriptive trend method
Compute direction, spread, jumps, and four-week comparison independently
The model reports a least-squares slope, coefficient of variation, largest positive weekly jump, and a latest-four to earlier-four ratio. None is labeled an injury probability.
Detailed calculation process and general formulas
Mean = ΣD_w / 8Slope = Σ(w - w̄)(D_w - Mean) / Σ(w - w̄)²CV = SD(D_w) / Mean × 100Jump_w = (D_w - D_{w-1}) / D_{w-1} × 100Four-block ratio = mean(D_5...D_8) / mean(D_1...D_4)Symbols, meanings, and units
- D_w
- distance completed in week wkm/week
- Slope
- linear direction across eight weekskm/week²
- CV
- coefficient of variation%
- Jump
- one-week percentage change%
- Four-block ratio
- descriptive latest versus earlier meanratio
Trend review
Four questions before changing the next week
The useful output is not a traffic-light label; it is a structured review of what changed.
Direction
—Is the series rising, falling, or broadly stable?
Concentration
—Did one week create most of the change?
Consistency
—Is week-to-week variability low enough to interpret the slope?
Context
Did pace, terrain, illness, pain, or life stress change at the same time?
Decision takeaway: Inspect the sequence first and use any ratio only as supporting context.
Applied decisions
Eight-week patterns that a single ratio can confuse
Steady build
Distance rises in small steps with one planned recovery week.
What the result clarifies: The area trace shows progression and recovery rather than just the block ratio.
Single catch-up spike
One large week follows missed training.
What the result clarifies: The jump marker reveals concentration that the mean can smooth away.
Worked default scenario
Current-input substitution and reconciliation
Method references
Evidence used to frame this specific model
Scope and limitations
This calculator does not predict injury. Research on simple workload changes and acute:chronic ratios shows methodological limitations and inconsistent associations. Pain, function, prior injury, intensity, terrain, recovery, and clinical context require separate judgment.
Running Training Trend Calculator | Eight-Week Mileage Analysis FAQ
Is the four-block ratio an ACWR?
It is a simple descriptive block comparison, not a validated injury-risk probability.
Why use eight weeks?
It provides two equal four-week blocks and enough points for a compact slope and variability review.
Should a zero week be excluded?
No, if it truly occurred; removing it changes the workload story.
Can distance alone measure load?
No. Pace, elevation, surface, session duration, and internal response also matter.