Today I have uncheck automatic calculate for those two fundamental values because now it's cleare that algorithm is full of errors. 3 days ago Garmin tell me an HRMax of 177 (my real is 184-185...) and after training I change it manually. Today it tell me that my new LTH Is 178 (real Is 168-169...), 1 more than HrMax calculate 3 days ago, really impossible and idiot. Every time that I run.I have HR Pro Plus belt, so there are not error. Garmin must change it very soon!!!