For the last few years, I thought that my max HR was 194. I've hit it a couple of times each year in tests. This year I have breached the figure 4 times, recording 198 at the end of a TT. My threshold, the HR I like to TT at, has also changed. Last few years it has been around 173, this year it is 180+. I've discovered all of this over the last couple of months, after a lay off over the winter, so I'm not at peak fitness for the season yet. Please can anyone suggest what is happening here - am I just unfit - so my heart is working harder, or has my latic acid tolerance improved. I know it would be easy to test if I had some data, eg power at certain HRs year on year, but general thoughts anyone please?