I am on Lopressor and have found it to keep my max in the range of 140-160 I am doing spin classes which make monitoring a bit easier as you don't have to watch for cars etc. What I found was when it felt like I was putting out max effort and just hanging on my heart rate is low in the 80-90 range. When it is in the 120-140 is when we are recovering so it is like I don't get the push when I need it and it goes up during recovery and then comes back down again. I am feel stronger with the higher heart rate. I have a mio fuze for a heart rate monitor and check some other activities like stairs and get the same effect. Am on blood thinner as well good news no stroke or heart attack.