Adaptive Increase Rate
Pheidi adjusts your weekly mileage increase rate based on your current volume. At lower mileage your body can handle faster jumps; at higher mileage the rate decreases to prevent overuse injuries.
| Peak Weekly Volume | Max Increase Rate |
|---|---|
| ≤ 30 mi (≤ 48 km) | 15% |
| 30 to 50 mi (48 to 80 km) | Linear interpolation (15% → 7%) |
| ≥ 50 mi (≥ 80 km) | 7% |
This replaces the rigid "10% rule" with a volume-aware approach backed by research (Aarhus University 2012, BJSM 2025).
3-Up-1-Down Pattern
Pheidi uses a 3-up-1-down progression pattern: three weeks of building volume followed by one recovery (down) week at 80% of the previous peak. This provides built-in recovery without needing separate deload scheduling.
Beginner Safety Cap
For beginners, week-to-week increases are capped at 50%. When this cap creates a gap between current volume and the target peak, Pheidi automatically inserts transition weeks (up to 4) to bridge the difference safely.
Adaptive progression runs inside the Pheidi app, sign in to build a plan.
Research & evidence
Science behind this feature from pheidi.training.
- Running Training Plan: The Complete Guide Pillar hub linking 48+ deeper dives, start here for the full picture.
- Mileage Progression: What the Science Actually Says A 2025 BJSM cohort study rewrote injury prediction for runners.
- The 10% Rule: Origin Story, Not Science Traces back to 1980s coaching, never to a controlled study.
- The 10% Rule Head-to-Head Trial 2008 trial of 532 runners found identical injury rates at 10% and 50% weekly increases.
- Why Running Apps Still Use the 10% Rule Safety-first product decisions outweigh nuanced research.
- The Weekly Volume Sweet Spot Injury rates minimize around 30 to 50 km/week for most runners.
- Step Loading and Bone Adaptation Why bones need 6 to 8 weeks at each new stress level to remodel.
- Build-Rest Cycle: Why Deload Weeks Matter 3-up-1-down weekly structure and supercompensation.
- Recovery Week Supercompensation How a 25 to 40% volume cut triggers fitness gain.
- The C25K Wall: Why Beginners Quit at Week 5 72.7% jump in continuous running is the real dropout driver.
- C25K Week 5 Dropout Wall The exact mechanics of why beginners quit a 300% increase week.
See also
- How Load Distribution Works How Pheidi shapes weekly distance around your long run using a shape-based system that keeps the hierarchy of run lengths consistent across the week.
- How Safety Guards Work How Pheidi protects you from training load spikes and injury risk: ACWR monitoring, session spike limits, and weekly volume caps based on running research.
- How Plan Generation Works How Pheidi builds your personalized marathon training plan: periodization, phase splits, shape-based load distribution, taper math, and base building.