Our company participated with several hundred runners in a 6,1 km fun run and I was lucky enough to get a press permit.
No big deal, because there was no exclusive back stage or the like. But I enjoyed being able to move around unrestrained by guards inside the big soccer stadium where the run finished.
1. If in doubt, always favor higher ISO (and maybe a little noise) and fast shutter speeds over low ISO. Aiming for less noise is worthless if the trade off is even the slightest movement (think of pixelwise "micro blur")
2. You can't plan for shooting huge crowds
I also assembled a new fixture to digitize my analog film this weekend ...