Run Smarter with Science — Your Running Performance Hub
Your science-backed running companion — training paces, race predictions, VO₂max estimation, and threshold analysis powered by peer-reviewed research.
Built by Runners, for Runners
Built on Science, Not Guesswork
Twelve specialized tools organized into three science-backed categories — from race prediction to threshold training to physiological analysis.
The Science Behind Your Paces
Every calculation is grounded in peer-reviewed exercise physiology research — from classic race prediction to modern threshold-based training.
Every Tool a Runner Needs
From training paces to race-day fueling — built by runners, backed by research.
See It In Action
Real calculator outputs — powered by peer-reviewed models.
What the Research Shows
Insights from the scientists whose work powers our calculators.
“Runners who train at the appropriate intensities — not too fast, not too slow — improve their VO₂max more efficiently than those who train by feel alone.”
Jack Daniels, Daniels' Running Formula (3rd ed., 2013)
On why VDOT-based training zones outperform guesswork
“The intensity distribution of successful endurance athletes is characterized by a large volume of low-intensity training, combined with a smaller proportion of high-intensity training.”
Stephen Seiler, International Journal of Sports Physiology and Performance (2010)
The research behind the 80/20 polarized training model
“The critical power concept provides a rigorous, physiologically-based framework for predicting performance across a range of endurance exercise durations.”
Jones & Vanhatalo, Sports Medicine (2017)
Why Critical Speed is the gold standard for multi-distance prediction
Built for Every Runner
Whether you're lacing up for your first 5K or chasing a sub-3 marathon, we have the tools.
Marathon First-Timer
Use the Training Pace Calculator for safe zones, the Carb Fuel Calculator for race-day nutrition, and the Lactate Threshold Calculator to understand your aerobic limits.
→ Training Pace CalculatorCompetitive Racer
Leverage the Race Predictor with the Hybrid model, dial in your LT1/LT2 paces with the Lactate Threshold tool, and build structured sessions with the Double Threshold Planner.
→ Race Time PredictorScience-Driven Athlete
Explore your lactate curve with the Lactate Simulator, structure 80/20 splits with the Polarized Training Calculator, and estimate your VO₂max from race results.
→ Lactate SimulatorRunning Coach
Access all 13 calculators to build individualized plans — from threshold-based zones to heat adjustments to nutrition targets for athletes of every level.
→ All 13 ToolsFrequently Asked Questions
Got questions? We've got answers backed by research.
Ready to Run Smarter?
Join thousands of runners using science-backed tools to optimize their training.