IIRC 284 runners in the 10k run, and I saw at least 38 in my age bracket.
I started at the back of the pack, as I considered myself to be a slow runner. After the first 1/2k, my breathing settled in, and I started to pass people. I was quite surprised how quickly I started grinding away at passing other runners. I know it's not really a competitive race, but for someone who struggled with 500-1000m runs in high school....
From about the 1k to the 5k mark I went back and forth with a pair of young fellas in their 20s. Around 5.5k, they fell behind and I didn't see them again.
Then around the 5.5-6k mark, I picked up another guy about my age and weight, and we went back and forth for a bit. He then fell off at around 7k, and made a sudden surge at 7.5k. Unfortunately, it was short lived, and I easily passed him. Didn't see him again until 9.5k, when he came dashing by...Only to turn off about 20m short of the finish line!!
The most amazing one was an old guy, who had to be 70. I thought I'd just grind him over like everyone else. But each time I drew up beside him, he'd pick it up a bit more and pull ahead again. He then made a dash for it at about 100m to the finish line.
I had certainly not burnt through my tank, but the one thing I didn't train in was dashing, so I had to maintain my pace to the finish line.
But I had trained for hills. Having prepared, I was able to use the down hill sections to accelerate past other runners. So while they hung back and changed their strides to break down hill, I leaned into it, widened my gate and used the hill and gravity for more speed. But what blew me away was the uphill sections. I thought I was weak in them, as I would struggle up them and end up winded. But I worked and worked at it. I guess it paid off, as not only did I take the hills...I accelerated up the hills and used them to do some major passing.
So I got a race shirt, a finisher's medal, and free food.
Afterward, I headed up to the weight room and did my upper body work out...Including about 80 push ups, and ab and butt work....Then I went home, had lunch, and went to work.
Edit...Looked a bit like this...
[video=youtube;Z5bXbJitRZg]http://www.youtube.com/watch?v=Z5bXbJitRZg&feature=related[/video]