[Edit: I'm going to CC this to my blog in lieu of a proper post]
Note to blog readers: what follows is a reply to my friend, Colin, who described a tough 22 km run last night. We had hoped to hook up, but it didn't work out.
That sounds like a really tough workout -- 22 km last night would have been gruelling. I'm also sorry I missed you. Just couldn't get away from work until about 7:30.
I got into the park at 8:20, having run smack bang into the bloody fireworks at Jingu. If I'd gone my normal route, I think I would have had rockets being fired up my backside! As it was I tried to skirt around and have a little bo-peep myself, but then I got completely stuck in a dead-end of jam-packed humanity. Pretty girls in yukata left, right and centre! People drinking beer and eating kakigori! It was almost enough to make me abandon the run. Almost.
I was able to turn around and re-trace my steps until it cleared out enough to move, then had to run along 246 from Aoyama-itchome to Omote-sando. Still very crowded on the footpaths, so I ran quite a bit on the road facing the on-coming traffic. Up Omote-sando not much better, and I surged up the section from Meiji-dori to the footbridge (upon which there were yet more bloody people watching the fireworks!). I did 2-1/2 solid laps in the park at 84%HRmax, yet the pace was only about 4:55/km. Unbelievable. As you described, in that oppressive humidity and heat it felt like I was really putting in a fairly hard effort, but the pace didn't match.
I then slid by the outside bar whereupon I met Gareth. Fueled up with two Yona Yonas, I headed for home. The stretch to the park and the stretch from the bar to home both produced average heart rates of 77%, but the first was at an average pace of 5:15, while the latter was an average pace of 5:50!!! (A couple of gratuitous exclamation marks there for you.). Total distance covered was a bit over 16 km, which I think at those heart rates will have done some good -- or at least I hope so.
On a positive note, my long-time niggling left leg is not too bad at the moment. I mean, it is actually fairly good. Touch wood. I now just have to tread very cautiously as I try to start increasing mileage.