Yesterday I did a ride I have done for years. 106 miles, 10,000’ climbing. Of course at 62 I don’t go as fast as when I was 30. In fact I strategize how to come back in one piece and enjoy the ride. Whopping 12.9 mph avg HR 123. I used HR for years before I got PM pedals so I make a habit of watching HR. I can tell without looking what my HR is. It varies but I know how it responds. There are some very painful hills on this ride. What PM does so much better than HR is tell me exactly when I want to shift on hills that have a rapidly increasing series of pitches.On short rides this concern about conserving energy is not as important but I don’t want to make the call of shame 50 miles from home!