http://blogs.msdn.com/ericgu/archive/2005/09/27/474446.aspxA couple of blog comments sparked the following question from Chris: As I rode the Zoo my heart-rate hovered between 180 and 184. 184 is the absolute highest I have ever seen for me on a bike. My resting heart rate is roughly 56. Out of curiosity....en-USCommunityServer 2.1 SP1 (Build: 61025.2)http://blogs.msdn.com/ericgu/archive/2005/09/27/474446.aspx#474552Tue, 27 Sep 2005 23:28:34 GMT91d46819-8472-40ad-a661-2c78acb4018c:474552Mark PearceOne reasonable indicator of fitness is the heart range, i.e. your max heart rate minus the resting heart rate - the latter figure goes down as you get fitter. <br> <br>Back in the days when I was fit enough to run a 2:29 marathon, I used to train with stars like Mike Gratton (2:09 marathoner, 1983 London Marathon winner). His max heart rate was significantly lower than mine, but his resting rate was low 30s! <br> <br>But heart rate is not nearly as good a metric for measuring cardiovascular fitness as your ability to utilise oxygen and your ability to buffer lactic acid production. http://blogs.msdn.com/ericgu/archive/2005/09/27/474446.aspx#475096Thu, 29 Sep 2005 01:24:09 GMT91d46819-8472-40ad-a661-2c78acb4018c:475096rezBased on your argument my heart should be as big as a walnut! My heart rate at rest is 96-100. <br>Of course there can be another explanation, I am a fatass asthmatic developer, who's sitting behind computer more than 14hr a day! <br>Shame on me.