Research
Every measure in our scoring system traces back to peer-reviewed research. Below are the 71 claims, anchored to 198 studies. Click any claim to see the studies behind it, the strength of the evidence, and the plans that respect it.
Adapting
- Bone is the slowest to catch up High
- Bone needs impact and fuel, not just miles High
- Tendons adapt slower than muscle High
- The body adapts on a staggered clock High
- The same pace starts to feel easier High
- Blood and tiny vessels change first Medium
- Trained runners gain durability, not VO2max Medium
- Your aerobic engine builds over weeks Medium
Biomechanics
Equipment
Heart
Injury
Intensity
- Build training zones around effort, not age High
- Easy miles do most of the work High
- Keep easy days easy, hard days hard High
- Polarized training beats threshold-heavy plans High
- Strides and sprints make you more efficient High
- Varied intensity beats a steady moderate pace High
- Short hard intervals work when time is tight Medium
Mileage
Nutrition
- Digesting food burns about 10% of your daily calories High
- Fat loss depends on the energy deficit High
- Formulas estimate resting calorie burn within about 10% High
- Fuel your training or the gains stall High
- Healthy eating fits a wide macro range High
- More protein protects muscle during weight change High
- A small calorie surplus builds muscle with less fat Medium
- Calorie estimates are useful but run high Medium
- Keep carbs high enough to fuel hard days while cutting Medium
- Lose weight slowly to keep muscle Medium
Performance
- Individualized plans beat one-size-fits-all High
- Recreational marathon pace sits below threshold High
- Three factors set your race speed High
- Threshold speed is built by running High
- A half marathon first protects new marathoners Medium
- Resilience is the fourth performance factor Medium
- Running economy improves faster than VO2 max Medium
- Your training data can predict a race time Medium
Race Preparation
- A taper makes you 2-6% faster on race day High
- Long runs are essential for the marathon High
- Race-pace training pays off near your threshold High
- Training in phases beats holding one load High
- Tune-up races don't improve marathon time Medium
- Fast-finish long runs are tradition, not proof Low
- Tune-up races may sharpen pacing Low
Strength
- Guided strength beats going it alone High
- Heavy lifting improves running economy High
- Jump training improves running economy and race times High
- Nordic curls cut hamstring injuries in half High
- Strength training keeps muscle while you cut High
- Strength training lowers injury risk High
- Strength training makes running more efficient High
- Two strength sessions a week is enough High
- Don't lift heavy right before a key run Medium
- Foot-strength work lowers injury risk Medium
- You can keep strength while cutting Medium
Other
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