Training & Nutrition - race warm-up

what's the best way to warm up for a race? and why is it a good way? i.e. what is the goal? warming muscles, 'priming' heart, beginning energy cycle/metabolism, etc.

i guess it various for events, but i do mostly 2-4 hour MTB races...

what i usually do is: about 20-30 minutes before the start i ride for 10 minutes in low gear with really fast spin and get my heartrate up to about 140 (70% max - my lactate threshold is about 165) for maybe 4-5 minutes. then i get to the starting line to take my place about 5-10 minutes before start.

i this enough? too long? what's the goal here? i learned TO warm-up but not really why and so i don't know best how...

P.S. i finished 124th out of about 400 in my 1st MTB race this year - 50km and 1100m vertical in 3:00:55 in Austria near Salzbug on Sunday April 21st and it was really muddy!

Click here for an article on this. (http://www.bike.com/features/template.asp?date=4%2F11%2F2002&page=2&lsectionnumber=5&lsectiondirectory=training) It was published very recently.

It doesnt hurt to stretch at the end of your warm up. Dont stretch cold, and dont use bouncing (ballistic) stretches. Martial arts classes are a good way to learn stretch techniques.
At the end of the race , do a cool down and stretch.

I just read the article suggested by Velo. It seems to make a lot of sense. Back when I was racing (as a junior), my best race ever was the Snowbird Hillclimb. My dad couldn't drive me to the start (20 miles away), so I rode (including getting stopped by a cop for riding a small section of interstate--the shortest route). I got to the race just in time, and flew up the mountain (a 10 mile race!). I didn't win my category, but I placed respectably and clobbered my previous best.

To the article I would add that you should take a good look at the first 10 km of the course. If it's a long race, then usually a short warm-up is a good option. But, if the race begins with climb, you should do a longer warm-up to be prepared for the climb in order not to be dropped at the beginning. I've got a war story there, too, but I'll spare you the details--it's not that exciting.

Also, get to the start line as late as possible (and still get a good position). I get pretty stiff in the joints after just a few minutes rest.

By the way, congrats on your performance on Sunday. It sounds like it was a great race.

Cheers,
Jamie

thanks velo,

that article was almost exactly what i was lookign for (OK maybe a little more technical stuff and formulas would be nice, but it was very helpful) - i had the general idea right, but it's good to understand why a little better... and to confirm that what i've been doing isn't totally wrong...