{
  "$schema": "https://wpl.dev/schemas/wpl/v1.schema.json",
  "version": "1.6.0",
  "plan": {
    "id": "plan_polarized_threshold",
    "name": "Polarized Endurance Week",
    "description": "Three-zone Seiler distribution: easy run (Z1), threshold (Z2), VO2max intervals (Z3). Plan-level athlete_thresholds let consumers convert zones to absolute HR/power.",
    "type": "workout",
    "visibility": "template",
    "metadata": {
      "tags": ["polarized", "endurance", "running"],
      "difficulty": "advanced",
      "estimated_duration_days": 7,
      "language": "en"
    },
    "goals": [
      { "id": "goal_vo2", "type": "primary", "category": "endurance", "name": "Improve VO2max and threshold" }
    ],
    "athlete_thresholds": {
      "hr_max_bpm": 188,
      "lthr_bpm": 168,
      "resting_hr_bpm": 48,
      "ftp_watts": 285,
      "vo2max_ml_kg_min": 58,
      "critical_pace_seconds_per_km": 215,
      "body_weight_kg": 72
    },
    "phases": [
      {
        "id": "phase_1", "name": "Polarized week", "order": 1,
        "type": "build",
        "duration": { "value": 1, "unit": "weeks" },
        "weeks": [
          {
            "id": "wk_1", "name": "Week 1", "order": 1,
            "days": [
              {
                "id": "d_easy", "day_of_week": 1, "name": "Easy run", "type": "training",
                "blocks": [
                  {
                    "id": "main", "type": "main", "order": 1,
                    "activities": [
                      {
                        "id": "run_easy", "type": "cardio", "name": "Easy aerobic", "modality": "running",
                        "prescription": {
                          "type": "continuous",
                          "duration": { "value": 60, "unit": "minutes" },
                          "intensity": {
                            "type": "heart_rate_zone",
                            "zone_model": "hr_3_zone_seiler",
                            "target": { "zone": 1 }
                          }
                        }
                      }
                    ]
                  }
                ]
              },
              {
                "id": "d_threshold", "day_of_week": 3, "name": "Threshold", "type": "training",
                "blocks": [
                  {
                    "id": "main", "type": "main", "order": 1,
                    "activities": [
                      {
                        "id": "run_thr", "type": "cardio", "name": "Threshold tempo", "modality": "running",
                        "prescription": {
                          "type": "continuous",
                          "duration": { "value": 30, "unit": "minutes" },
                          "intensity": {
                            "type": "heart_rate_zone",
                            "zone_model": "hr_3_zone_seiler",
                            "target": { "zone": 2 }
                          }
                        }
                      }
                    ]
                  }
                ]
              },
              {
                "id": "d_vo2", "day_of_week": 5, "name": "VO2max intervals", "type": "training",
                "blocks": [
                  {
                    "id": "main", "type": "main", "order": 1,
                    "activities": [
                      {
                        "id": "run_int", "type": "cardio", "name": "5x4 min @ 95% LTHR", "modality": "running",
                        "prescription": {
                          "type": "intervals",
                          "intensity": {
                            "type": "heart_rate_zone",
                            "zone_model": "hr_3_zone_seiler",
                            "target": { "zone": 3 }
                          },
                          "intervals": {
                            "work": { "duration": 240 },
                            "rest": { "duration": 180 },
                            "repeat": 5
                          }
                        }
                      }
                    ]
                  }
                ]
              },
              {
                "id": "d_long", "day_of_week": 7, "name": "Long run", "type": "training",
                "blocks": [
                  {
                    "id": "main", "type": "main", "order": 1,
                    "activities": [
                      {
                        "id": "run_long", "type": "cardio", "name": "Long Z1", "modality": "running",
                        "prescription": {
                          "type": "continuous",
                          "duration": { "value": 90, "unit": "minutes" },
                          "intensity": {
                            "type": "pace",
                            "zone_model": "pace_critical_speed",
                            "target": { "percent_of_critical": 75 }
                          }
                        }
                      }
                    ]
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  }
}