My mare has always worked about 15 to 20 bpm higher than most horses I have trained or ridden with. I have just learned that that is her way. Some people say that if their horse hits 140 they slow down. If I did that I would not get anywhere. I have been competing with this mare for 8 years now and she does well, so I have just learned that this is her way of going. Mare has always been a little on the heavy side, but I got some serious weight off her this year. It helped with recoveries and CRI's. It did drop her working pulse a tiny bit, but she still runs higher than most horses though.