Running after work for a change

Another first today - a run after work in the work vicinity.  No time for a lunchtime run due to meetings and car insurance crises, and anyway I'm becoming aware there's a risk that the time limit on lunchtime running creates a risk I'll not get a longish midweek run in.  It's very tempting to go for the sociable, easy option of 5 or 6 miles, and depending on who I go with the pace can be pretty easy too.

So - with Rich off in Toulouse learning about managing risk in European banking (and eating sausages, I expect) I decided to go out from work, after work.  I was quite taken with the Riddlesden road the other day, and am equally enthused by the idea of building up to a longish MP run midweek.  I did half a mile nice and slow, then kicked on at what was intended to be 6:45/6:50 pace, with the intention of running 8m at that pace then half a mile warm down for 9m.

My pace judgement was fine for the first three, with miles of 6:51, 6:47 and 6:46, but then I started to speed up and did every mile faster than the last, running 6:41, 6:36, 6:31, 6:28 and 6:26 to finish.  Whilst running faster may be good for the ego, I need to practice running to a pace.  Part of the problem seems to be using the current pace measure on my Garmin - maybe I should use lap pace to smooth out a bit of the lumpiness.  If I see "6:58" on the screen then I tend to push on a bit, similarly if I'm feeling the pace a bit then I naturally assume I'm slowing down.
 

My HR was utterly nuts - hitting 254(!!!!!) apparently, and averaging 199 for the session.  This is nonsense, but thankfully a post on the Garmin forum explained the problem - wateror  sweat in the workings - as demonstrated by the green gunky bits on the contacts and a rusty, recently installed battery.  New, posher one ordered from Wiggle forthwith, with a tenner off if you spend fifty, I got a tub of Power Bar lemony powder thrown in, and all for less than the price of the strap alone.  Hopefully this will enable me to get my pacing right in future!