Garmin contacted me and were not happy about how Intervals.icu has been using their “backfill old data” API endpoint (too many calls, large date ranges). They explained that it puts a lot of stress on their systems and they prefer developers not to use it at all and only work with new activities. I explained why history is valuable on Intervals.icu and they agreed to allow calls to fetch history going back up to a year.
This applies to activities and wellness data. I have implemented this limitation in Intervals.icu. The “Fetch old data” and “Fetch activities since” options will now not go back further than one year.
Garmin have actually been pretty good about this. A lot of big tech companies would have just disabled API access and I would have spent weeks trying to get it restored. I received email from a real human to connect via teams and discuss the problem and it is now sorted out without any API interruption.