{
  "_meta": {
    "title": "Houston Dawn Run Fuel Calculator Constants",
    "author": "Bhartiben Patel",
    "location": "Houston, Texas, USA",
    "version": "1.0.0",
    "license": "CC0-1.0",
    "sources": [
      {
        "id": "compendium-2011",
        "name": "Compendium of Physical Activities",
        "wikidata": "Q1924756",
        "year": 2011
      },
      {
        "id": "acsm-hot-env-2020",
        "name": "ACSM Position Stand: Exercise in Hot Environments",
        "publisher": "American College of Sports Medicine",
        "year": 2020
      },
      {
        "id": "usda-fooddata-20067",
        "name": "USDA FoodData Central Entry 20067",
        "subject": "Cooked White Rice Composition"
      }
    ]
  },
  "met_values_by_speed_km_h": {
    "8": 8.0,
    "10": 9.8,
    "12": 11.0,
    "14": 11.8,
    "16": 14.0
  },
  "humidity_correction_formula": {
    "expression": "HCF = 1 + 0.004 × (RH − 50) + 0.015 × (T − 25)",
    "variables": {
      "RH": {
        "unit": "percent",
        "range": [30, 100],
        "typical_houston_summer": 75
      },
      "T": {
        "unit": "celsius",
        "range": [10, 45],
        "typical_houston_summer": 31
      }
    },
    "threshold_warning": 1.4
  },
  "rice_conversion_constants": {
    "carbohydrate_fraction": 0.28,
    "glycemic_index": 73,
    "digestion_window_minutes": [60, 90],
    "optimal_ingestion_offset_minutes": 75
  },
  "hydration_model": {
    "base_ml_per_kg": 35,
    "humidity_multiplier_expression": "1 + (humidity - 50) / 200",
    "duration_scaling": "linear"
  },
  "thermal_safety_thresholds": {
    "wet_bulb_critical_celsius": 24,
    "action_below": "reduce pace or shift to 05:00 departure"
  }
}