Zwiftout

Zwift workout generator command line tool and library.

Used as engine for the online workout-editor.

Motivation

Creating custom workouts is a pain.

The workout editor in Zwift is pretty clumsy and slow to use:

• drag'n'drop is not the fastest way to edit,
• positioning of messages is especially tricky as they easily jump out of place,
• there's no copy-paste functionality to speed things up.

Editing .zwo files by hand is also inconvenient:

• you'll have to constantly convert minutes to seconds,
• you can easily make errors in XML syntax, rendering the file invalid,
• it's really a bad format.

There are a few alternative editors online:

• ZWOFactory is very much point'n'click based which doesn't help much with speeding up the process.
• Simple ZWO Creator is more akin to my liking as it's text-based. But it's lacking lots of features: no way to add cadence, text messages, warmup/cooldown etc. The syntax used is also kinda confusing.

Features

• Fully text-based workout creation.
• Easily add cadence targets.
• Easily place text-messages within intervals.
• Support for Warmup/Cooldown & FreeRide interval types.
• Automatic detection of repeated intervals - conversion to <IntervalsT> in .zwo file.
• Generation of stats: average and normalized intensity, TSS, zone-distribution.

Install

$ npm install -g zwiftout

Usage

Write a workout description like:

Name: Sample workout
Author: John Doe
Tags: Recovery, Intervals, FTP
Description: Try changing it, and see what happens below.

Warmup: 10:00 30%..75%
Interval: 15:00 100% 90rpm
  @ 00:00 Start off easy
  @ 01:00 Settle into rhythm
  @ 07:30 Half way through
  @ 14:00 Final minute, stay strong!
Rest: 10:00 75%
FreeRide: 20:00
  @ 00:10 Just have some fun, riding as you wish
Cooldown: 10:00 70%..30%

Feed that file into zwiftout program, which spits out Zwift workout XML:

$ zwiftout my-workout.txt > my-workout.zwo

Also, you can query various stats about the workout:

$ zwiftout --stats my-workout.txt

Total duration: 65 minutes

Average intensity: 50%
Normalized intensity: 75%

TSS: 60

Zone Distribution:
 14 min - Z1: Recovery
  6 min - Z2: Endurance
 10 min - Z3: Tempo
 15 min - Z4: Threshold
  0 min - Z5: VO2 Max
  0 min - Z6: Anaerobic
 20 min - Freeride

Usage as library

import { parse, generateZwo, stats } from "zwiftout";

const workout = parse(`
Name: Sample workout
Warmup: 10:00 30%..75%
Interval: 15:00 100% 90rpm
`);

// Output ZWO file
console.log(generateZwo(workout));

// Output various statistics
console.log(stats(workout));

TODO

• Repeats (and nested repeats)
• Unsupported params: message duration & y-position
• More restricted syntax for text (with quotes)
• Concatenate similar intervals
• Distinguish between terrain-sensitive and insensitive free-ride.