Marathon Race Predictor
Predict your marathon time based on a recent race result (5K, 10K, Half) using the Riegel formula.
🌤️ Running Conditions
| Distance | Predicted Time | Avg Pace /km |
|---|---|---|
| 5K | 25m 0s | 5:00 |
| 10K | 52m 7s | 5:13 |
| Half Marathon | 1h 55m 0s | 5:27 |
| Marathon | 3h 59m 47s | 5:41 |
| 50K Ultra | 4h 47m 2s | 5:44 |
The Standard: Riegel's Formula
This calculator uses Peter Riegel's formula:T2 = T1 * (D2 / D1) ^ 1.06. This assumes you have the appropriate aerobic base for the target distance.⚠️ The "Endurance Gap"
A fast 5K time shows a large engine (VO2 Max), but a Marathon requires Metabolic Efficiency. * The Wall: Your body stores ~2,000 calories of glycogen. A marathon burns ~2,600. Without fueling, you will "hit the wall" at Mile 20 (32km).📈 Metabolic Flexibility & Fueling
To bridge the endurance gap, athletes must train their bodies to oxidize fat at higher intensities. * Carb Loading Protocol: Increase carb intake to 8-10g per kg of bodyweight for 36-48 hours before the race to maximize glycogen stores. * During Race: Aim for 60-90g of carbohydrates per hour.📉 Prediction Accuracy by Weekly Mileage
| Weekly Mileage | Reliability | Impact |
|---|---|---|
| < 30km** | **Poor | Survival mode only. |
| 60-90km** | **High | Prediction is highly accurate. |
| > 100km** | **Extreme | Might beat the prediction. |
🌡️ Environmental Scaling (The Heat Tax)
Temperature is the greatest "un-predictor" of race performance. * Ideal: 45°F - 55°F (7°C - 13°C). * Warm (> 70°F / 21°C): Add 5-15 seconds per kilometer to your goal pace to avoid overheating. * Dew Point: High humidity prevents sweat evaporation, driving core temperature up exponentially.Use Cases / Example Scenarios
Targeting 30:00 and this pace chart confirmed I was overtraining my easy runs. Adjusted and feel great.
Hit a new PR today using the 100kg exercise chart. Best volume guide I've found online.
Used this for my Marathon Race Predictor training. The split at 30:00 was exactly what I needed to finish strong.
These scenarios are illustrative examples based on typical use cases.
WinSport Editorial & Research Standards
"All formulas and reference values used in this tool are sourced from peer-reviewed scientific literature and validated clinical guidelines. Our research team continuously audits each calculator for accuracy and updates methodology as new evidence emerges."
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