It is probably easier (and you are more likely) to run your training runs too fast than run your races too slow. Have a look at the McMillan Calculator to get a better idea of what you should be doing on your training runs.
Just finished a very long run yesterday (20miles), I was running 1km and walking for 1 minute. I devloped a pain in my left knee exactly where my IT band is at the knee, but unlike previous experiences the pain developed when walking and eased on running. When I started to walk it took 45s to develop and disappeared a few seconds after starting to run again. This is totally contrary to the normal ITBS pattern. The left side of L knee is a little bit painful today.
T.mouse, I am specifically running 10ks, Club Training tends to concentrate on shorter intervals 200s-400s occ 800s and Longer tempo runs, although I can never seem to run them at anywhere near my race pace. I had a whole year off competitive running and have really just started back.The layoff was initially due to injury abut I never quite got back into racing again (fear of failure perhaps). I think I am lacking spefic speed endurance and perhaps I need to up the work on doing longer intervals 1km+ to try and get some endurance for the longer distances. As an ex-sprinter I tend to go all out from the start and hope to hold on, as you suggest perhaps I need to pace a little better. I find this hard. Certainly when I achieved my best times I was constantly watching my pace and adjusting, rently I have been looking at the lap times as they elapse, hoping they would be good, invariably not, which saps my energy a bit - hence the loss of focus. I run around 40-45km per week, over 4 days - easy (10), intervals(10), tempo(13), & long run (15-20km).
I have wondered whether in the past I was relying on the races to give me the speed endurance but with the long layoff I have lost this element of my training.
I too would like to run a sub 40 (again). The last time I managed this was two years ago when I ran 39:44, however I am currently running around the 42:00 mark. The problem is whilst I have the starting speed I seem to get much slower in the middle part of the race i.e. first 3-4k are ok, but thereafter my form seems to collapse. I can pick it up a bit in the last 1k. Any suggestions as to the problem and the corrective action required, other than running faster