{
  "schema_version": "1.0",
  "plan": {
    "id": "hybrid-engine-6wk",
    "name": "Hybrid Engine 6-Week",
    "author": "Universal Fit",
    "description": "Two strength days and two aerobic days for users who want lifting progress without losing their running base.",
    "goal": "mixed",
    "level": "intermediate",
    "duration_weeks": 6,
    "days_per_week": 4,
    "tags": ["hybrid", "strength", "running", "barbell"]
  },
  "mesocycles": [
    { "id": "base", "name": "Base", "weeks": [1, 2, 3] },
    { "id": "build", "name": "Build", "weeks": [4, 5, 6] }
  ],
  "weeks": [
    {
      "week": 1,
      "days": [
        { "day": 1, "name": "Lower Strength", "estimated_minutes": 65, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 4, "set": { "reps": 5, "load": { "percent_1rm": 72 }, "rest_seconds": 180 } } }] }] },
        { "day": 2, "name": "Zone 2 Run", "estimated_minutes": 40, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 40, "hr_zone": 2 } } }] }] },
        { "day": 4, "name": "Upper Strength", "estimated_minutes": 60, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 4, "set": { "reps": 5, "load": { "percent_1rm": 72 }, "rest_seconds": 180 } } }] }] },
        { "day": 6, "name": "Strides", "estimated_minutes": 35, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "intervals", "modality": "running", "warmup": { "duration_minutes": 12 }, "intervals": [{ "repeat": 6, "work": { "duration_minutes": 0.5 }, "rest": { "duration_seconds": 90, "type": "walk" } }], "cooldown": { "duration_minutes": 8 } } }] }] }
      ]
    },
    { "week": 2, "days": [{ "day": 1, "name": "Lower Strength", "estimated_minutes": 65, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 4, "set": { "reps": 5, "load": { "percent_1rm": 74 }, "rest_seconds": 180 } } }] }] }, { "day": 2, "name": "Zone 2 Run", "estimated_minutes": 42, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 42, "hr_zone": 2 } } }] }] }, { "day": 4, "name": "Upper Strength", "estimated_minutes": 60, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 4, "set": { "reps": 5, "load": { "percent_1rm": 74 }, "rest_seconds": 180 } } }] }] }, { "day": 6, "name": "Strides", "estimated_minutes": 36, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "intervals", "modality": "running", "warmup": { "duration_minutes": 12 }, "intervals": [{ "repeat": 7, "work": { "duration_minutes": 0.5 }, "rest": { "duration_seconds": 90, "type": "walk" } }], "cooldown": { "duration_minutes": 8 } } }] }] }] },
    { "week": 3, "days": [{ "day": 1, "name": "Lower Strength", "estimated_minutes": 65, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 4, "set": { "reps": 4, "load": { "percent_1rm": 76 }, "rest_seconds": 180 } } }] }] }, { "day": 2, "name": "Zone 2 Run", "estimated_minutes": 45, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 45, "hr_zone": 2 } } }] }] }, { "day": 4, "name": "Upper Strength", "estimated_minutes": 60, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 4, "set": { "reps": 4, "load": { "percent_1rm": 76 }, "rest_seconds": 180 } } }] }] }, { "day": 6, "name": "Strides", "estimated_minutes": 38, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "intervals", "modality": "running", "warmup": { "duration_minutes": 12 }, "intervals": [{ "repeat": 8, "work": { "duration_minutes": 0.5 }, "rest": { "duration_seconds": 75, "type": "walk" } }], "cooldown": { "duration_minutes": 8 } } }] }] }] },
    { "week": 4, "days": [{ "day": 1, "name": "Lower Strength", "estimated_minutes": 68, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 5, "set": { "reps": 3, "load": { "percent_1rm": 78 }, "rest_seconds": 210 } } }] }] }, { "day": 2, "name": "Zone 2 Run", "estimated_minutes": 48, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 48, "hr_zone": 2 } } }] }] }, { "day": 4, "name": "Upper Strength", "estimated_minutes": 62, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 5, "set": { "reps": 3, "load": { "percent_1rm": 78 }, "rest_seconds": 210 } } }] }] }, { "day": 6, "name": "Tempo Intervals", "estimated_minutes": 42, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "intervals", "modality": "running", "warmup": { "duration_minutes": 10 }, "intervals": [{ "repeat": 4, "work": { "duration_minutes": 4 }, "rest": { "duration_seconds": 120, "type": "jog" } }], "cooldown": { "duration_minutes": 8 } } }] }] }] },
    { "week": 5, "days": [{ "day": 1, "name": "Lower Strength", "estimated_minutes": 68, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 5, "set": { "reps": 3, "load": { "percent_1rm": 80 }, "rest_seconds": 210 } } }] }] }, { "day": 2, "name": "Zone 2 Run", "estimated_minutes": 50, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 50, "hr_zone": 2 } } }] }] }, { "day": 4, "name": "Upper Strength", "estimated_minutes": 62, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 5, "set": { "reps": 3, "load": { "percent_1rm": 80 }, "rest_seconds": 210 } } }] }] }, { "day": 6, "name": "Tempo Intervals", "estimated_minutes": 45, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "intervals", "modality": "running", "warmup": { "duration_minutes": 10 }, "intervals": [{ "repeat": 5, "work": { "duration_minutes": 4 }, "rest": { "duration_seconds": 120, "type": "jog" } }], "cooldown": { "duration_minutes": 8 } } }] }] }] },
    { "week": 6, "days": [{ "day": 1, "name": "Lower Strength Deload", "estimated_minutes": 45, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_back_squat", "sets_template": { "count": 3, "set": { "reps": 5, "load": { "percent_1rm": 65 }, "rest_seconds": 150 } } }] }] }, { "day": 2, "name": "Easy Run", "estimated_minutes": 35, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "steady", "modality": "running", "target": { "duration_minutes": 35, "hr_zone": 2 } } }] }] }, { "day": 4, "name": "Upper Strength Deload", "estimated_minutes": 45, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "barbell_bench_press", "sets_template": { "count": 3, "set": { "reps": 5, "load": { "percent_1rm": 65 }, "rest_seconds": 150 } } }] }] }, { "day": 6, "name": "Easy Strides", "estimated_minutes": 32, "blocks": [{ "type": "main", "items": [{ "kind": "exercise", "exercise_ref": "running", "cardio": { "structure": "fartlek", "modality": "running", "target": { "duration_minutes": 30 }, "notes": "Stay relaxed. Finish feeling fresh." } }] }] }] }
  ]
}