Runners- anyone run a training run faster than their race PR?

This is so frustrating!

I've run over 10 5K's, a 10K, a half-marathon, and a full marathon in the past year and a half.

My current focus is improving my 5K speed.  I've been doing hills, intervals, and tempo runs to achieve this.  I ran my 1st 5K in April 2007, in 26:58.  My last 5K, June 2008, was 24:28.  In July, I ran a one-mile race in 6:34.  When I input that one mile time into the McMillan calculator, it says I could run a 5K in 22:45 (not 24:28!)  ALSO, there have been 2 occasions in the past few months where I have run a 3 mile tempo training run in 22:30...  which would be about a 23 minute 5K.

SO WHY IS IT I CAN'T RUN FASTER ON RACE DAYS?????  The only thing I can come up with is nerves... is it possible that my heart rate is higher at the start of a race and that's why I can't go faster?  Anyone have any tips on how to make my next 5K (next Saturday) the one I FINALLY run a sub-24?

I'm not sure what kind of training you are doing, but two recommendations for preparing for any kind of distance race:

- make sure you are getting some good rest the week or two before the race. I cut my peak mileage by at least half. In the final week, do one short, fast workout during the week (200m repeats or similar) and a short, easy run the day before the race.

- on race day, make sure to warm up by jogging for at least half a mile. This will help calm your nerves and get you in the rythm of running.

- don't put too much pressure on yourself & have fun!

Something to think about is that your training runs of 3 miles may not be actually 3 miles long.  A race usually is certified distance, at least most of the bigger races are.  You could be running 2.8 miles and not knowing it on your training route.  I like to take the day off before a race.  Some people take the day 2 days before a race off and do a short easy run the day before, but that's just personal preference.  The McMillan calculator is just an estimate of how fast you can run, it can vary quite a bit depending on how many miles a week you put in.  I run one day of intervals and one day of temp runs a week, then 3 days easy and one day long, and one day rest.  Keep up the speed work and remember to rest one or two days a week and your times should come down.