How can I access the best maximum pulses in the last 42 days? I don’t know if this is possible
Yes you can:
Example pulling the athletes MMP power curve for the last 42 days (from activity date) and extracting best 5m power:
let mmp42d = icu.bestPower['42d']
let best5mWatts = mmp42d.getWatts(5 * 60)
Sorry I just realised you were probably looking for heart rate data. You can do:
let hr42d = icu.bestHR['42d']
let best5mBpm = hr42d.getBpm(5 * 60)
Everything available is listed here.
Any chance to access fit file messages as in custom activity fields?