"stretching" as you people refer to it is a whole universe in itself.
it's a means to power and full range of motion, that is to undo the damage of aging, training, and less than perfect living.
it works.
but the traditional runners or western ideas are horsseeshit. binary logic,
it needs to be custom. yoga chick instructors are usually wacked out and over do it.
people that don't stretch, or rather understand basics of yoga don't get it.
however there are many converts.
the idea that you can touch your toe and do the splits is some kind of great thing are ill informed.
there are a million kinds of stretches, breathing, before and after workouts.
yoga chicks regularly have problems with overdoing it,
with running is you're doing some really hard work, you don't want to stretch too much and wait for recovery,
light work to get the blood to flow is in order.
if you're healthy and recovering you won't need to do so much yoga,
for sure if you over stretch you're going to lose some muscle tension, some of which is useful. and you'll be noticeably slower,
at the end of the day, in the off season everyone should try yoga, and give it several weeks for the lights to come on.
basically if you notice how your body is going, you're going to clue into what you need, rather than some moronic static schedule,
so I've said nothing precise here, well too bad, go figure it yourself, yoga is something to love, it grows on you.
I definitely wouldn't want my runners doing the splits however, ….
at a minimum do yoga on the muscles that are in obvious bad shape, like Moorcroft calves, there are half a dozen exercises that are good to great,
such is the nature of this paradigm, asking such a completely stupid question, does stretching help.