gf_200,
At this time, we could suggest doing a few blocks, med ball throws, etc. But, I have found that giving the athlete the choice in what gets them the most prepared is what we do, as long as it fits. Both for the mental aspect and they know their body (or should) better than we do.
When warming up for specific endurance, I do part 1&2 of Gerard Mach’s warm-up, it takes about 20-25 minutes to do and when I have completed Part 2, I am ready for specific endurance or a Meet for that matter.