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One Rep Max API

Estimate 1RM from submaximal lifting performance and return strength planning targets.

Endpoint

  • GET /api/v1/fitness/one-rep-max
  • POST /api/v1/fitness/one-rep-max/post

Parameters

Name Type Required In Description
weight number Yes Query/Body Weight lifted.
reps integer (1-15) Yes Query/Body Completed reps.
formula string No Query/Body epley, brzycki, or lander; defaults to epley.
lang string No Query Response language (en,fr,es,de,pt,ja,hi,ar,bn,gu,id,it,ko,mr,nl,pa,pl,ro,ru,ta,te,th,tr,ur,vi,zh).

Request Example

curl -X GET "https://api.hefitapi.com/api/v1/fitness/one-rep-max?weight=100&reps=5&formula=epley&lang=en" \
  -H "X-API-Key: YOUR_API_KEY"

Response Example

{
  "weight": 100.0,
  "reps": 5,
  "formula": "epley",
  "one_rep_max": 116.67,
  "submaximal_load_chart": {
    "95_percent": 110.83,
    "90_percent": 105.0,
    "85_percent": 99.17,
    "80_percent": 93.33,
    "75_percent": 87.5
  },
  "strength_estimate_band": "reliable",
  "summary": "1RM estimate is reliable for programming when reps are low to moderate.",
  "recommendations": [],
  "language": "en",
  "_api_metadata_": {"endpoint_name": "one_rep_max", "response_language": "en"}
}

Localization

This endpoint reads health_fitness_one_rep_max.json from the supported language catalogs.