A TypeScript library for parsing and building Intervals.icu workout text format. Convert workout text into a structured AST or programmatically construct new workouts.

Features

Parsing

• Convert workout text into structured AST
• Parse with zone info to calculate duration, TSS, and intensity factor
• Support for section and step repeat calculations

Building

• Fluent builder API for creating workouts programmatically
• Serialize workouts back to Intervals.icu text format
• Configure duration, power/HR/pace targets, cadence, and ramps

Example

import { parse, build } from 'intervals-icu-workout-parser';

// Parse existing workout
const ast = parse('5m @ 50% + 3x(10m @ 90% + 5m @ 60%) + 5m @ 50%');

// Build a workout programmatically
const workout = build()
  .step('5m', { power: '50%' })
  .repeat(3, (r) => r
    .step('10m', { power: '90%' })
    .step('5m', { power: '60%' })
  )
  .step('5m', { power: '50%' })
  .toString();