Convert training prescriptions to Intervals.icu workouts with Claude Opus AI

Description

Transform training prescriptions into perfectly formatted Intervals.icu workouts using AI. This workflow automatically converts free-text workout descriptions into structured interval training sessions with proper heart rate zones, pace calculations, and exercise formatting.

What this workflow does

1. Collects workout details via a web form (date, title, and workout description)
2. Fetches athlete data from Intervals.icu (FTP, max HR, threshold pace, LTHR)
3. Processes with AI using Claude Opus 4.1 to intelligently parse and format the workout
4. Auto-detects workout type (Run, Ride, Strength, HYROX, CrossFit, etc.)
5. Converts training zones - RPE → HR%, pace calculations, power zones
6. Formats workout structure with proper transitions, rest periods, circuit formatting
7. Creates the workout in Intervals.icu via API

Use cases

• Coaches: Convert training plans from documents/spreadsheets into Intervals.icu format
• Athletes: Quickly add structured workouts from coaching apps or training programs
• Hybrid training: Handle complex HYROX, CrossFit, or multi-sport sessions with circuit formatting
• Time savings: Eliminate manual workout entry and zone calculations

Supported workout types

Running, cycling, swimming, strength training, HYROX, CrossFit, indoor rowing, virtual training (Zwift), triathlon, and more.

Key features

✅ Intelligent workout type detection
✅ Automatic RPE to HR zone conversion using athlete-specific data
✅ Proper formatting for intervals, circuits, supersets, and progressions
✅ Adds transitions between exercises/machines
✅ Calculates exercise durations and pacing
✅ Handles warmup/cooldown sections
✅ Generates unique workout IDs

Setup requirements

• Intervals.icu account with API access (API key required)
• Anthropic API key for Claude AI
• Athlete must have training zones configured in Intervals.icu (FTP, max HR, LTHR, threshold pace)

Setup instructions

Getting your Intervals.icu API key

1. Log in to Intervals.icu
2. Go to Settings (gear icon) → Developer Settings
3. Click Generate API Key (or copy your existing key)
4. Save the API key securely

Configuring credentials in n8n

For Intervals.icu (HTTP Basic Auth):

1. In n8n, open the GetAthleteInfo or CreateWorkoutAPI node
2. Click on Credentials → Create New Credential
3. Select HTTP Basic Auth
4. Enter:
   • Username: API_KEY (literally type "API_KEY")
   • Password: Your actual API key from Intervals.icu
5. Click Save
6. Apply this credential to both HTTP Request nodes

For Anthropic:

1. Open the Anthropic Chat Model node
2. Click on Credentials → Create New Credential
3. Enter your Anthropic API key
4. Click Save

Important: The Intervals.icu API uses HTTP Basic Authentication where the username is always the literal string "API_KEY" and the password is your actual API key.

How it works

The workflow uses a sophisticated AI agent with a detailed system prompt that understands training terminology, zones, and Intervals.icu formatting requirements. It applies sport-specific rules to ensure workouts are properly structured for tracking during training sessions.