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Heart Rate Zones API

Return heart-rate reserve zones with actionable coaching context for fat loss, endurance, and performance optimization.

Endpoint

  • GET /api/v1/fitness/heart-rate-zones
  • POST /api/v1/fitness/heart-rate-zones/post

Parameters

Name Type Required In Description
age integer (13-90) Yes Query/Body Athlete age in years.
resting_hr number (30-130) Yes Query/Body Resting heart rate in bpm.
goal string Yes Query/Body fat_loss,muscle_gain,maintenance,endurance,recomposition.
max_hr number (120-230) No Query/Body Maximum HR; if omitted, age-based estimate is used.
lang string No Query Response language (en,es,de,fr,pt,ja,hi,ar).

Why Use This Endpoint

  • Deliver ready-to-train heart-rate zones per user profile.
  • Align session prescriptions with goal and readiness.
  • Support coaching automations with consistent zone logic.

Get Started

Request Example

curl -X GET "https://api.hefitapi.com/api/v1/fitness/heart-rate-zones?age=33&resting_hr=58&goal=endurance&lang=en" \
  -H "X-API-Key: YOUR_API_KEY"

curl -X POST "https://api.hefitapi.com/api/v1/fitness/heart-rate-zones/post?lang=en" \
  -H "Content-Type: application/json" \
  -H "X-API-Key: YOUR_API_KEY" \
  -d '{"age":33,"resting_hr":58,"goal":"fat_loss","max_hr":188}'

Response Example

Info

The response example below is for demonstration purposes only. Make a live request to this endpoint to receive the full, real-time, and potentially richer JSON structure.

{
  "goal": "fat_loss",
  "goal_label": "Fat Loss",
  "age": 33,
  "resting_hr_bpm": 58.0,
  "max_hr_bpm": 188,
  "max_hr_source": "provided",
  "heart_rate_reserve_bpm": 130,
  "zones": {
    "zone_1": {"label": "Zone 1", "min_bpm": 123, "max_bpm": 136},
    "zone_2": {"label": "Zone 2", "min_bpm": 136, "max_bpm": 149},
    "zone_3": {"label": "Zone 3", "min_bpm": 149, "max_bpm": 162},
    "zone_4": {"label": "Zone 4", "min_bpm": 162, "max_bpm": 175},
    "zone_5": {"label": "Zone 5", "min_bpm": 175, "max_bpm": 188}
  },
  "fat_burn_zone": {"zone": "zone_2", "label": "Fat Burn Zone", "min_bpm": 136, "max_bpm": 149},
  "vo2_optimization_zone": {"zone": "zone_4", "label": "VO2 Optimization Zone", "min_bpm": 162, "max_bpm": 175},
  "threshold_zone": {"zone": "zone_4", "min_bpm": 162, "max_bpm": 175},
  "anaerobic_power_zone": {"zone": "zone_5", "min_bpm": 175, "max_bpm": 188},
  "readiness_signal": {"level": "high", "level_label": "High", "note": "Recovery indicators support quality intervals."},
  "goal_session_guidance": ["2 threshold intervals", "1 long zone-2 block"],
  "training_notes": {
    "warmup": "Build progressively for 10-15 minutes.",
    "cooldown": "Use 8-10 minutes low-intensity recovery.",
    "zone_switching": "Transition gradually when moving between zones."
  },
  "summary": "Balanced zone strategy optimized for fat-loss efficiency.",
  "language": "en",
  "_enterprise": {
    "client": "Acme Health",
    "plan": "pro",
    "request_id": "f6b9fb31d4f2a027",
    "quota": 120,
    "usage_tracking": true
  },
  "_api_metadata_": {
    "endpoint_name": "fitness_heart_rate_zones",
    "response_language": "en"
  }
}

Product Positioning

Ideal for connected fitness wearables, coaching dashboards, and endurance training automation.

Note

max_hr is optional. When absent, the API estimates max HR from age with the Tanaka formula.