The real difference in Marathon Training between the recent past and today, is the different interpretation we have about how to build the right fuel.
The secret of top Marathon runners is the ability in changing your engine.
As my English is not very fine, may be that is difficult to explain the idea, but I try.
We have a table. On this table there are 3 different containers : one is full of FAT, another is full of GLYCOGEN, and a third is empty. The athlete must learn to create the optimal mixture, taking part of it from one container, part from the other.
At the beginning, running at a supposed Marathon Pace (MP), he goes to use a lot of glycogen, and little fat.
When we go for the test of lactate (6 x 2000m even pace, including the MP, with 40.0 recovery, plus 1200m free at end : for example, at the beginning of the preparation for an athlete having the goal to run at 3:05 per km (2:10:08), we go for 2000m at the following speeds :
6:30 - 6:20 - 6:10 - 6:00 -5:55 - 5:50), we can see the level of lactate producted for every EVEN speed. From the lactate level, we understand which type of fuel the runner is using : higher is the level, more glycogen you use running.
In this case, one example is as follows (3 months before the race) :
6:30 1.7 mml
6:20 2.3 mml
6:10 3.4 mml
6:00 4.8 mml
5:55 5.8 mml
5:50 7.6 mml
Because there is not a STEADY LEVEL, the athlete at the moment is not able to run a full marathon at 3:10 (2.3 mml is a normal level of speed for running a marathon), but finish his fuel earlier,may be about 32 km.
You continue your training, EXTENDING THE DURATION OF LONG FAST RUN and of SPECIFIC MARATHON ENDURANCE TRAINING (for example, 3 x 5000m in 15'25" alternated with 1 km in 3'45", become 4 x 5000 at the same speed). After one month, you go for the test again, and these are the results :
6:30 1.4 mml
6:20 1.8 mml
6:10 2.2 mml
6:00 2.8 mml
5:55 4.6 mml
5:50 6.4 mml
We are starting to build a STEADY STATE between 6:20 and 6:10 speed, that means adaptation for a new type of fuel, less rich of glycogen and richest of fatty acids.
When you are really ready, you can have a final test as follows (we cancel the slowest, and use steps of 5.0 only) :
6:20 1.6 mml
6:15 1.8 mml
6:10 2.0 mml
6:05 2.4 mml
6:00 2.8 mml
5:55 3.8 mml
5:50 4.6 mml
Normally, for controlling HOW MUCH GLYCOGEN you have still in your tank, we use a final 1200m free. If you are able running at a level of 7-9 mml, it means that you have yet a lot of glycogen in your tank.
So, for PUSHING the athlete to chose,among the fatty acids, the ones having higher energetic power, WE HAVE TO PUT IN CRISIS THE MUSCULAR FIBRES AND THE BODY.
We start running FAST, for example, 28 km at 3:10 pace, waiting that the tank of glycogen becomes empty. After 28, suddenly you run 3:30 and after 3:45. THE REAL TRAINING ARE ONLY THE LAST 2 KM, THE FIRST 28 HAD THE GOAL TO USE THE FUEL YOU HAD IN THE TANK.
When the body is in difficulty, our fibres pay more attention to the ability in chosing and selecting and using the fats with more energetic power. The next long run fast, our athlete is able to last, at the same speed, not 28, but 30 km, going in crisis after that mileage.
So, now WE START FROM THE INTENSITY.
In the past, starting from LONG SLOW RUN, we had a lot of km NOT ABLE TO CHANGE OUR ABILITY IN SELECTING THE FATS MORE POWERFUL.
Not all the fats have the same level of power. Is like the coal : coke and anthracite are different kinds of coal, with the first we can last a lot of time with not many calories, with the second we can have a higher level of calories per minute, but it finishes in shorter time.
So, to change the SPECIFIC MARATHON ENDURANCE means not to run a lot of km without influence on the bioenergetic system, BUT TO CHANGE THE ABILITY IN CREATING THE RIGHT FUEL. And this is possible only putting our body in crisis, so the fibres are able to recognize the best fats and to use them, reducing the use of glycogen at the Marathon Speed.
Now, we cannot depend on the tests for knowing the speed possible to run. WE GO DIRECTLY TO BUILD THE ABILITY OF THE BODY IN RUNNING AT A WELL IDENTIFIED SPEED, before the race. WE BUILD EXACTLY THE MARATHON WE WANT.