Been using STRAVA on my iPhone the last six weeks or so after returning to cycling from a years-long hiatus. I'm 74 now, STRAVA default tells me my Max Heart Rate is 190, which is absurd. How do I go about altering that little bit in my Profile on the phone app to reflect a more modest 160 or so? I can sustain 120 for a few minutes now, touch 150+ briefly w/no issues. It's the proportional representation of max vs. endurance periods I want to have presented with more accuracy.