Last week my heart rate would hardly get over 130 no matter how hard I was riding. Previously my max heart rate was 155. I thought that maybe my monitor was going bad so I got my wife to wear it to the gym and compare it to the reading on the eliptical machine. She came back and said that it was within 1 beat per minute. I had been riding 20 miles a day for about 5 days so I decide to take a 35 mile ride. I just let my heart rate hang around 120 and at the end of the ride I feel good and almost tried for another 20 miles but decided why ruin a good thing. The next day my nephew calls and wants to go fishing so I decide to skip my ride and we go fishing. I play in the creek and swim while he fishes. So all this leads up to today. I head out on my ride and see that my heart rate is high even while I am taking it easy. I am at a rate of 120 with almost no effort and 12 mph. I start up a hill and get a little winded I take a look and I am at 140 but my legs are not tired. There is a pretty long hill on my route at about my 15 mile mark and I use it to try and see what my maximum heart rate is. So I start up the hill at 14 mph and the heart rate is 145 in about 2 minutes it is at 150. Another minute and it is 155. I try to see if I can get it higher and I start heaving in about 20 seconds and the rate did not go over 155.
So after saying all this all I can conclude is that some days my precieved exertion is that I have had it at a heart rate of 120 and another day I can hit a rate of 145 and not feel all that bad.
Do you find this to be true for yourself?