The v2 is here: 5,800 exercises and muscle heatmaps. Explore the v2

GymFit API

The exercise API for fitness apps

5,800 exercises with their target and secondary muscles on three levels, steps, difficulty, variants and alternatives. A search that reads typos and abbreviations, a muscle heatmap for each exercise, and BMI, BMR and TDEE calculators.

Free plan, no credit card. 1,000 requests a month.

GET /v2/exercises/squat-barbell

Show full response
{
  "name": "Squat (Barbell)",
  "slug": "squat-barbell",
  "category": "Strength",
  "difficulty": "Intermediate",
  "force": "Push",
  "equipment": "Barbell",
  "primaryGroups": [
    "Quadriceps",
    "Glutes"
  ],
  "secondaryGroups": [
    "Adductors"
  ],
  "targetMuscles": [
    {
      "name": "Quadriceps femoris",
      "commonName": "Quads",
      "group": "Quadriceps"
    },
    {
      "name": "Gluteus maximus",
      "commonName": "Glutes",
      "group": "Glutes"
    }
  ],
  "secondaryMuscles": [
    {
      "name": "Adductor magnus",
      "commonName": "Adductor magnus",
      "group": "Adductors"
    }
  ],
  "variations": [
    {
      "name": "Front Squat (Barbell)"
    },
    {
      "name": "Box Squat (Barbell)"
    }
  ],
  "alternatives": [
    {
      "name": "Air Squat"
    },
    {
      "name": "Lunge"
    }
  ],
  "easier": [
    {
      "name": "Air Squat"
    }
  ],
  "harder": [
    {
      "name": "Overhead Squat (Barbell)"
    }
  ]
}
Muscle heatmap of the squat, front and back: Quadriceps femoris, Gluteus maximus highlighted
Target: Quadriceps femoris, Gluteus maximus. Secondary: Adductor magnus.

An exercise database built for developers

exercises
5,800exercises
muscles in 21 groups
49muscles in 21 groups
types of equipment
33types of equipment
movement families
136movement families

Used by 1,600+ developers.

Everything your fitness app needs in one API

A search that reads what people type

Typos, abbreviations, plural forms and muscles named in plain words: rdl, bech press, quads. Results are ranked by relevance, then by how often the exercise is done.

rdl
  • Bench Press (Barbell)Barbell
  • Squat (Barbell)Barbell
  • Deadlift (Barbell)Barbell

A muscle heatmap for every exercise

One SVG, front and back, with the target and secondary muscles colored. Set the colors to match your app.

Muscle heatmap of the bench press: pectorals highlighted, shoulders and triceps in a lighter shade

GET /v2/exercises/{id}/heatmap

Muscles on three levels

21 groups, 49 muscles and their heads, each with the name people use.

  • group Chest
  • muscle Pectoralis major (Pecs)
  • head Clavicular (Upper)
  • head Sternal (Lower)

Variations, alternatives and progressions

Offer a variation, an alternative when the machine is taken, or an easier and a harder version.

Squat (Barbell)
variationsFront Squat (Barbell)Box Squat (Barbell)
alternativesAir SquatLunge
easierAir Squat
harderOverhead Squat (Barbell)

Fitness calculators

BMI, BMR, TDEE and ideal body weight, one request each.

male, 180 cm, 78 kg, 25 years, active

BMI
24.1
BMR
1,785 kcal
TDEE
2,927 kcal
Ideal weight
75.1 kg

From sign-up to your first exercise in a minute

  1. Create a free accountAn email and a password, no credit card.
  2. Copy your API keyIt is shown once, in your dashboard.
  3. Call the APISend the key in the X-API-Key header.
curl "https://api.gymfit-api.com/v2/exercises/search?query=squat&equipment=Barbell" \
  -H "X-API-Key: $GYMFIT_API_KEY"

What developers build with GymFit API

Workout trackers
Log sets and show the muscles each session worked, from the target and secondary muscles of every exercise.
Muscle heatmaps
Count the weekly volume per muscle group, or draw the heatmap of a session with the SVG of each exercise.
AI workout generators
Give your model structured exercises, muscles, variations and alternatives instead of free text.
Coaching platforms
An exercise library with steps, tips, common mistakes and progressions for your clients.

Exercise API pricing

Start free, upgrade when your app grows. Prices in USD, taxes included.

Free

$0 a month

  • 1,000 requests a month
  • 30 requests a minute
  • Requests beyond the quota are refused
  • Prototypes and non commercial projects
  • MCP server for AI assistants
Get a free API key

Starter

$9 a month

  • 20,000 requests a month
  • 60 requests a minute
  • Then $0.002 per extra request
  • Commercial use, 1 app
  • MCP server for AI assistants
Choose Starter

Pro

$29 a month

  • 100,000 requests a month
  • 300 requests a minute
  • Then $0.001 per extra request
  • Commercial use, 5 apps
  • MCP server for AI assistants
Choose Pro

Data pack

$399 once

  • The whole catalog, as files you own
  • A durable copy for your app, offline included
  • 12 months of updates
  • The only offer to store the data yourself
What is in the data packBuy the data pack

Every plan includes every endpoint. Cancel anytime from your dashboard.

Exercise API FAQ

Is there a free exercise API?

Yes. The GymFit API free plan includes 1,000 requests a month and 30 requests a minute, with every endpoint and no credit card. It is meant for prototypes and non commercial projects.

What data does each exercise include?

Name, category, difficulty, force, equipment, type (compound or isolation), laterality, target and secondary muscles, step-by-step instructions, tips, common mistakes, variations, alternatives and easier and harder progressions. A separate endpoint draws the muscle heatmap of the exercise as an SVG.

Does the API include exercise images?

No. The v2 does not serve photos or animations. Each exercise has a muscle heatmap (an SVG of the body, front and back, with the muscles colored) that you can match to your app. The legacy v1 keeps its image fields for existing integrations.

Which muscles does the API cover?

49 muscles in 21 groups (chest, lats, quadriceps, hamstrings, glutes, abs...). Every exercise lists its target and secondary muscles, and a muscle comes with its common name, its aliases and its heads.

How does the search work?

It reads typos (bech press), abbreviations (rdl, ohp), plural forms and muscles named in plain words (quads, abs no equipment), and ranks the results by relevance, then by how often the exercise is done. Filters cover muscle, equipment, category, difficulty, tier and more, and options add a suggested spelling or counts per filter.

Which fitness calculators are included?

BMI, BMR (Mifflin-St Jeor), TDEE by activity level and ideal body weight (Devine formula), one request each.

Can I use the exercise API from Claude, Cursor or another AI assistant?

Yes. GymFit is also an MCP server. In Claude or ChatGPT, add it as a custom connector and sign in with your GymFit account; in Claude Code, Cursor, VS Code or Windsurf, add it with your API key. Your assistant then searches the exercises, finds alternatives and runs the calculators for you. Each tool call counts as one request of your plan, the free plan included.

Can I use GymFit API in a commercial app?

Yes on the Starter and Pro plans: one API key for one app on Starter, up to five on Pro. The free plan is for prototypes and non commercial projects. Reselling the data or building a competing database is not allowed (see the terms of use).

Can I store the data in my own database?

Not with an API plan: use the responses to serve your users, without keeping a durable copy of the catalog. The data pack is the offer to own the catalog: bought once, from your dashboard.

What happens if I exceed my plan limits?

On the Free plan, requests beyond the monthly quota are refused until the next month. On paid plans, your API keeps working: each extra request is billed at your plan's rate at the end of the month. You can follow your usage in real time from your dashboard.

Can I cancel my subscription at any time?

Yes, from Manage billing in your dashboard, with no commitment or cancellation fee. Your plan stays active until the end of the current billing period.

Is my payment information secure?

Payments are handled by Stripe, which acts as the merchant of record and processes your card on its PCI-compliant platform. Your card details never reach our servers.

I subscribed through RapidAPI. Does anything change?

No. Your RapidAPI subscription keeps working as before, and its billing stays with RapidAPI.

What languages does the API support?

All exercise data and responses are in English. If your app needs another language, tell us: new languages are prioritized by demand.

Do you offer technical support?

Yes, by email at contact@gymfit-api.com. Mention the X-Request-Id of a response and we can find the request.

Build your fitness app on real exercise data

Get a free API key