Hurdler/high jumper/sprinter here:
There is no one correct distance or time for the warm-up, but the basics should be similar. In general, start off easy, get loosened up and get your blood flowing, and slowly increase the intensity of the drills you are doing until you are ready to make a 100% effort. I posted my hurdle warm-up on another thread, here it is:
"I run a different race than most of you but hopefully someone will appreciate this! For the 60 Hurdles or the 110s, I start about an hour and a half before the race:
-Walk around for a couple minutes
-Jog for 10 minutes picking it up towards the end
-10 minute dynamic warmup - series of skips, carioca, etc. with lots of dynamic stretching worked in
-Sprint drills (A skip, B skip, bounding, etc.)
-hurdle drills - a couple walkovers but not much, just to wake up some muscle memory
-put on spikes
-hurdle drills part 2 - running over shorter hurdles lead, trail, over the middle
-2-3x 30m-40m accelerations up to full speed
-a few block starts over the first 2 hurdles until the race, full recovery in between
-Race: make sure to get the first couple steps down very quickly so the excitement of the race doesn't cause you to be too close to the first hurdle"
For an open sprint like the 100 or 200, you don't need to start quite as long before the race since you don't need to do hurdle drills, but I would still start at least 30-45 minutes before the race. I would keep the same general structure:
- Easy jog
- Series of skips, carioca, etc.
- Dynamic stretching (don't go nuts, you're not trying to gain a ton of flexibility with this, just wake up the flexibility you have)
- Sprint drills
- A couple accelerations
It is very difficult to over-warm up for a 100 or 200. To be prepared to sprint, you should definitely be breathing hard and sweating during the warm up. I would definitely recommend doing a few short sprints of 20-30 meters at maximum effort before the race. Of course, you don't want to work to the point where you are getting lactic acid build up and muscle fatigue, but you also don't want your first 100% effort of the day to be when the gun goes off, so make sure you are giving yourself time to fully catch your breath in-between, and that your full speed sprints are short.
The last thing I'll mention is consistency. Just like distance running, you don't want to change things up too much on race day. My practice warm-up and race day warm up are very similar, with the main difference just being that on race day it is a little more important to focus on a little bit of real speed at the end, since in practice it's okay to not be 100% at your fastest at the beginning of the workout.
I hope this helps! I'd love to hear input from other sprinters/coaches. As I said, the specific drills are less important than the overall goals: slowly build intensity, make sure to work up a sweat and get loose, then do something snappy and get ready to go fast. Good luck with your racing and training!