Today's run lasted not much more than seven minutes, but the entire time I was running as fast as I could (I mean, without the extra burst of adrenaline that being pursued would lend me). You'll note that my average pace for this run was 9'20"! On a "normal" run (where I'm expecting to spend 3x as long moving and cover 3x the distance) I run on average an entire 1'30" slower than that... and that's on a good day!
The point of a tempo run is to make you sustain a quicker than comfortable pace for longer than you're used to. And again, since I'm just starting out, 7 minutes at 9'20" is a heroic effort.
I'm interested to see the effects of this training over longer distances, too. But I'm not rushing it. I've made that mistake before and it always leads to quitting before I've reached my goal. But I'd really like to succeed this time! So... onward... one run at a time.