Warm-ups (for the really slow)

So with my first 5K coming up, I've been reading about what kind of warmup I should do before the race, and the thing is, I'm so slow that there's no such thing as an easy jog that won't start to tire me.

Will brisk walking do much to warm my running muscles? I'm thinking no more than 10-15 minutes jogging before the race, but I know I'm going to need more warmup than that, especially considering start time is oh-dark-thirty. But the minute I transition from walking to jogging, my HR goes over 155 (80% of max). As I've said before, my running HR zones are really, really narrow.

Any recommendations?

I'm pretty slow. I don't like to do alot of warming up before a race, and only a minor bit of stretching. I'll usually jog from where I parked over to the start if it's not far. I might do some lunges and I will stretch out my arms and back. I've found that since I'm not that great of a runner, warming up doesn't do a huge deal for me.

When I run on the treadmill I always walk 0.05 miles at a brisk pace to warm up my muscles, so I would think that walking would be ok for you.

Here's what I might do before a 5k: 1.5 - 2 mile run, start out really slow and easy but run the last half mile at or close to race pace... depending on your pace, you could actuallly fit this warmup within 15 minutes. Since a 5k is such a short race, you're running at a pretty high per cent of max hr, and you want to warm up to that level for at least a short distance before the race.

I notice that in training, it takes me about a mile to feel warmed up (so that everything "feels good", stride feels easy and coordinated and breathing is easy) in warm weather, and closer to two in colder weather.