Ari and vederci, I confirm that the 48 hours are a complete bullshit. Also an idiot understands that, IF my goal is to have some session with more intensity than in the past (in extension, or in intensity, or both together), BECAUSE I THINK THAT WITH THIS TYPE OF SOLLECITATION (of course alternated with the right recovery) YOU CAN REACH YOUR BEST SHAPE WHEN YOU NEED, and this is the only way for reaching the top of what you can do, automatically we need to open the recovery.
So, you consider the basic point of your training the same recovery and the continuity, I consider the intensity of the training and the modulation. We have a exactly an opposite idea of training.
All your considerations about what you need for building your "aerobic house" (I see now a lot of people use this words, that I used first in one congress some year ago for explaining what an athlete of middle distance has to do in his career) are connected with an obsolete idea of aerobic. When I came Kenya for the first time, I had many thing to teach, and a lot of thing to learn.
One of these, for example, was the different mentality between European and African about their athletics necessities. In 2001, I went from Sankt Moritz to Heusden for the meeting together with the athletes with me in training, from different Countries. In the group there was Sergey Lebid from Ukraine, European Cross Country Champion, with PB of 7'35" and 13'10", and Mark Bett, coming from a 12'55" run in Oslo. We arrived at 1:30 in the night. Immediately after having the room, Mark Bett disappeared, and went to sleep till the evening. Sergey went running 30' in the dark, because "without running after a long trip I don't feel comfortable".
So, for African runners the priority is to have their tank full of energy, nervous and physical, and for reaching their goal, sometimes rest is better than training.
For European and American, the priority is to have continuity, also if their training is no training. This is a mental problem, nothing to do with physiology.
At the time of Lydiard, somebody said that not running one day brings an athlete to lose a small percentage of his shape. This is a typical mentality for amateurs, because the truth is exactly the opposite : top champions NEVER have complete continuity, but use a very big modulation were training of very high intensity and recovery have the same importance, because one is not possible if there is not the other.
In Africa, every day we have some emergency. We don't know if tomorrow there is rain or not, and if there is roads are so muddy that may be better to rest. Injuries are the normality with this type of situation. Family problems are very common, and every problem goes back to the best runners for a solution. Do you think in this situation the base of everything is the plan, or is the ability of the coach in managing day by day every situation, following a phylosophy but not a precise plan ? Coaching in Africa means to have a periferal vision of a lot of problems, and inside this vision to organise the workouts. And you speak about 48 hours !
The fact is that too many western scientists, methodologists, coaches created a system based on the only things they knew : the reality of our Countries.
I have for you a very easy question.
You have an athlete running with little training 33' in 10k. After 3 months of good training he becomes able running 31'. The question is : WHY ?
This athlete was able running, before this training, in the same way used 3 months later. So,there was not a technical improvement. What changed ?
With training he changed his physiology. So, physiology is not mathematics, where you can have a calculation and after you can apply the calculation to some projet that you develop following rules (for example, you can calculate the parabol of a rocket for going around the Moon, and after you can build everything exactly as your calculation, and you succeed). Physiology can only study what really happens in the human body, and, till when something DOESN'T HAPPEN, physiology doesn't have any possibility to check the phenomen.
In this picture, normally physiologists NEVER are able to work with top athletes, and do the mistake to extend their experiences (done with normal persons) to top Champions.
Top Champions : WHY ARE THEY TOP CHAMPIONS ? There are many reason, but one is that they HAVE SPECIFIC ATTITUDES VERY DIFFERENT FROM THE RANGE OF NORMAL PEOPLE. Not only, but having more attitude, they can look for more important results, so their training is more professional, there is more volume and more intensity, they can dedicate a period of their life full time to their training, and this means THE BASIC GAP BETWEEN THEM AND NORMAL PEOPLE BECOMES BIGGER EVERY DAY.
Never there was a scientist creating something new in training. Instead, there were coaches without any knowledge of physiology (one of them was ecatly Lydiard) but with the idea to explore some new area, able to create a psychological feeling with some athlete, that tried something new, and in some case the supposed human barrier were overtaken. And after, only after, their system became a general method, used in all the World.
Try to understand that there are not physiological laws, about recovery, training, aerobic, thresholds, specific endurance, strength, biomechanics, etc., because EVERY person is different from another person, and EVERY IDENTICAL RESULT is produced, by different athletes, using different percentages of the same qualities.
At the end, coaching is not a science : is an art. And artists need to know science, but scientists don't need to know art.