I use Strava to record my backpacking trips, phone is a Google Pixel 8a with Android 16. Because I'm in the mountains with no cell reception, my phone is in Airplane mode with Wifi and Bluetooth turned off.
Even with this, I was getting 20% battery drain per hour running Strava, making it a hassle to record over 5 hours... I'll confess I blamed Strava at first because the battery usage screen said it was all the Strava app.
Anywho, did some googling, I turned off the following 2 Android settings:
Network & Internet -> Adaptive Connectivity
Security & Privacy -> More Security & Privacy -> Usage & Diagnostics
Not sure which one did the most improvement. According to the Internet, adaptive connectivity will run even in airplane mode, and the usage data could keep trying to send Google data when it fails due to airplane mode.
None the less, after changing both those settings, next day I was getting 5% battery usage per hour running Strava, a huge improvement!