Heart Rate Query

I would be grateful if someone could shed some light on the following and maybe provide a rational explanation and also re-assure me I am not about to expire!

I PB'd in a 10k on Nov 4th. (7 min 40secs per mile off about 8 weeks of 15ish miles a week training). I have done minimal running since (about 5 miles once a week)  I just bought a HR monitor and went for a run at what I thought would be an easyish pace even bearing in mind loss of conditioning (around 9 min milles). I was suprised to see my HR at a constant 188bpm at this pace and up to 200 when I sped up to 7.5 min miles for the last half a mile. The effort level did not seem ridiculously hard (apart form at the end) Does this mean I have got very unfit quickly cos otherwise this would imply I ran a 10k at about 200 bpm which is surely impossible or very unhealthy. Any comments appreciated.

How old are you Scottles ? 

This does'nt sound right to me but i'd expect one of the more experienced runners wiil tell you more.  It sounds far to high to me,  my max HR is 186 and i'm 39 and have been running on and off for years.

Thanks for this, I think the monitor was working fine as when I starte walking it went down to 120 and then down to 100 when I sat down afterwards and 60 at rest, which seems about right. I will do a max heart rate test soon, this would imply mine must be at least 210 which I thought was maybe a bit worrying.

oh I am just 36 btw