If you read our blog religiously (no one), you may find that some time ago, I wrote about stretching. Be my guest, read it if you haven't (it still has some real value)... but if you want the cliffsnotes (I always opted for those), I didn't speak highly of it. Basically, there's a lot of research proving that runners with tighter hamstrings are often more efficient then runners with a greater range of flexibility. Moreover, even if you value your flexibility, actually lengthening your muscles is darn near impossible! (especially as an adult) So I basically stated in my last post about stretching - what's the use?!
Let's try a little experiment here. Put down your laptop, get on the floor and do some serious ab work. Do some crunches and whatnot, and then do this particular ab exercise (this one always produces the affect I'm going for here). Don't stop, and don't let your feet touch the ground for as long as possible. I'd say at least 45 seconds. If you start going really slow because you just can't do it any more, that's ok, just keep doing it. When you stop, let your feet and back drop to the ground. Try and relax your abs. You can't do it can you. My stomach remains painfully tight after doing those for about 15 seconds, and even after that, my abs remain tight. That's how your legs are after running, and without stretching, they'll remain that way! Again, muscles aren't noticeably shorter, they're just tighter, less relaxed.
So let your muscles relax - stretch them out after your workouts. It doesn't have to be a long stretching routine, just 5 or 10 minutes. Make sure you hit up the sore places - nothing to strenuous, just enough to get some fresh blood flowing in there. I promise - it'll be helpful.