VO2 Max from ORM Fit Files in Intervals.icu

[DXCanas]

Hi all,

For any Intervals.icu users:

I noticed that TCX files had the VO2max calculations "baked in" to the files using description. I thought that was nice, for portability. I was bummed that Fit files didn't (Though they get them automatically uploaded as descriptions on Intervals and Strava).

That is, until I discovered they were in fact written there! To a standards-compliant field, no less!

Sadly, it seems very few encoders (even Garmin) don't use the purpose-built field.

But I wanted to see it in the interface, so I created a custom field to show in the summary. It would look like this:

Why would I need this if it's in the description, you may ask?

Having it as a field makes it easier to compare using Intervals' spreadsheet capabilities. So you can see how each workout's calculated VO2max differs or changes over time, average them out, etc. It's neat! And if you prefer to manually pull the file and upload it yourself, you get to keep it without having to go to the TCX to grab the string 🤷

The field is public. But search is very basic, and there's a lot of VO2Max results. I added a description mentioning ORM and max_met_data that should help it stand out. Reprocess the file after adding the Custom Field to see it in your Summary pane 👌

Or, if you want to write your own, here's the code inside. Should also be visible there:

{
  let vo2max = null;

  if (icu?.fit?.max_met_data?.length > 0) {
    for (let msg of icu.fit.max_met_data) {
      const fields = Object.values(msg || {});
      
      // Find the field that contains "vo2_max" in its name getter
      const vo2Field = fields.find(val => 
        val !== null && 
        typeof val === 'object' && 
        val.name && 
        String(val.name).includes("vo2_max")
      );

      if (vo2Field && vo2Field.value !== undefined && vo2Field.value !== null) {
        vo2max = vo2Field.value;
        break; // Stop iterating once we find the first valid VO2 Max
      }
    }
  }

  vo2max;
}

A little overly cautious (thanks, LLMs) but it works! Feel free to make it neater if you like 😄