I appreciate very much your intervention, because it's possible to see that education doesn't have anything to do with intelligence. If you in the future need (I hope not for you) some surgery and the best doctor is a French not speaking English, may be you prefer to die...
May be you prefer to talk using your fluent Italian.
In any case, we are speaking about athletics, not about English. In athletics, the only language are the results, and the methodology we use for reaching them.
About warm up and warm down, I want to precise my position :
a) These practices are strictly SUBJECTIVE. Everybody can use it in different way, depending on event, weather, shape, attitude, training conditions.
In 1988 (OG Seoul), I saw an incredible warmup of Edwin Moses (3 hours before the final of 400 HS) and of Jackie Joyner (before the last afternoon of Eptathlon) : they put in their warmup an unbelievable attention, with a lot of analytic exercises, only after more than 2 hours of wup going to something more global.
In WCh 1995 (Goteborg), I saw Michael Johnson before his races : almost 2 hours on the bed for massages, with his physio (a lady) helping with stretching step by step more hard, but without running. Half hour before the competition, about 100m straight with normal shoes, then he put his golden spikes, one full turn at high speed, after he removed and went to win. And, after the race, almost 20' continuous jogging, in order to remove the lactate from his muscles.
If you see the Wup of Bekele and the Ethiopians, they run their last 10'/15' very fast. Kenyans jog very slowly, and sometime the results are the same.
But, if for example you run a cross with 0°, jogging is useless, because you are not able to "break the breath". You need some minute fast, exactly like when we have to warm the engine of a car when is very cold. In this case, Kenyans are wrong.
I suggest every athlete to try different solutions, and to chose the best for himself. So, I explain the physiological effects of Wup and Wdwn, but at the end the best teacher is the personal feeling : when they feel better, this is good (I remember Christopher Koskei running 3 hours in St. Moritz when I wrote 1:30:00, telling me that, after it, he felt better).
In any case, we must remember a rule :
a) More fast is training, more warm-up you need
b) Warm-down after a session of long run is not only useless, but ridicolous, because we do the same thing of training : better running 10' or 15' longer, without any warm-down. Wdwn is important for removing lactate, but after long run the level of lactate is very low, so.....
c) Better go for stretching when muscles are already a little bit prepared. So, I'm absolutely against the idea to start training with stretching. If we have time, we start with 10' progressive running from easy to moderate, THEN stretching, then training.
d) Personally, I don't believe too much in stretching ALONE. I prefer to combine stretching with dynamic exercises, in order to STRETCH THE MUSCLE in a longer way. If we want to improve our elasicity, we need to OVERSTRETCH our muscles, and this is not possible using the classic stretching, that is ISOMETRIC.
In any case, speaking about middle and long distances, I confirm my idea :
I saw athletes beating WR without any exercise of stretching, but using a lot of training for increasing their metabolic ability.
At the same time, I never saw any athlete with wonderful stretching, wonderful technique and wonderful postural balance, reaching top performances in middle distances without a very tough training of endurance for increasing his threshold and specific metabolic attitude.
Running fast is fatigue : with stretching, there is no fatigue, so many times to give too much importance to this practice means to reduce focus in what is really useful for our events.