Fast Miles - Disappointing Data

Just ran my first fast miles since June 14th. My favorite 5 miler that goes from my house, out to Los Altos Hills and back. A mile of roads to start, then 1.5 miles of trails with a nice little climb at mile 2. It's a run that I've done many times so I was interested to get a good comparison to my pre-injury runs.

Started out easy at 8:00 pace for the first mile, then progressively picked things up. Fastest pace dipped just under 7 (haven't seen 6:5x on the watch for a very long time!) and the mile splits were 8:02, 7:30, 7:19, 7;32 and 8:00. Average overall was a respectable 7:44 for just over 5 miles. It was nice to get moving quickly again after such a long break. Didn't feel too strained, and achilles was fine, but I know my heartrate was pretty high and the average was 165 (which is usually what it is for a half marathon)

On May 28th I ran this exact same route, in very similar weather at the same sort of pace. That run was a slightly steeper progression (8:30 down to 6:54) but average pace was similar (7:41). Heartrate for that run was only 154. So I'm up 11 beats for a tempo run. Or put another way, I'm running slower at 165 than I used to. Previously that heartrate, for that sort of distance would have been run at around 7:15 pace, so I've lost about 30 seconds/mile since the end of May, which is pretty depressing. Guess I should have run a little harder in the pool on some of those days....

So I have my work cut out for me if I'm going to get back to where I was for the 10k in 23 days. I was blindly hoping that I'd be able to match my pre-injury best of 42:51 (6:54 pace) but all the signs right now suggest a pace more like 7:25 which is right around what I was running way back in January (46:25 10k on New Year's day). I'll be really happy if I get down to 42:51, and really disappointed if I'm way back at 46:25. Chances are that I end up somewhere in the middle.

Of course, I need to do all this without buggering up my achilles again, which has been OK through these first few weeks back, but I'm obviously at fairly high risk of doing too much too soon. Let's see if I can manage to reign in my enthusiasm long enough to do this properly.