I fully agree with Antonio. In choosing a type of training, I try to analyze the characteristics of every athlete. I\'m not AGAINST plyos and weights, but I\'m not PRO these trainings. Simply, there\'s some athlete that can have advantage using it, and some other not.
Plyo is good for increasing elastic strength and muscle reactivity. So, if you have an athlete already talented under this point of view (for example, Cherono has wonderful feet), what is the reason for using this type of training ? I prefer to use short sprint for increasing explosive strength, and medium hills (till 800m) for increasing the strength endurance. I tried also, with Shaheen, to do short sprints (80m about) uphill with 2 hurdles 91cm high : this is a very difficult exercise, but I think that can produce very high specific strength endurance for steeple.
Another important thing, when you have to choose a type of training, is the relation between ADVANTAGES and RISKS. Personally, I don\'t agree that plyo and weight can give 1% of improvement, but of sure can give 30% of risk. A lot of athletes fall down in some injury due to plyo.
And you must always remember that we are speaking about EVENTS OF ENDURANCE, so the most important problem is ENZYMATIC. About a good balance between strength and endurance, for example, I propose you the following test (only for marathon runners) :
a) The Faraggiana - Gigliotti test for investigating lactate level after 6 x 2000m improving speed every time, with very short recovery, at the beginning of the preparation.
b) The same test developing the special period of training for specific marathon endurance
c) The same test while you train the athletes for increasing their strength.
You can see that, without using strength training, the level of lactate REGARDING MARATHON PACE is going down, meaning the gradual adaptation of fibres in using, for the same speed, a mix of glycogen and fatty acids with, step by step, more fat and less glycogen (that means to be able to last more long time at the same speed).
But you can also see, using strength training, that, while strength is growing (every test can show it), the level of lactate regarding the marathon speed doesn\'t go down, on the contrary often goes up.
So, what is the role of the strength in the marathon ? Of course, if you have too low strength, you cannot run well, but if you are strong but not able to reuce the consumption of your fuel, you cannot finish the race.
Always a good training must look at the best connection between the different types of training, according to the personal individual qualities, in order to prepare the best performance possible.
In events of endurance, the main dish is SPECIFIC ENDURANCE, after a very extended base of GENERAL RESISTANCE and SPECIAL ENDURANCE. All other type of training (plyo, weights, technical exercises, stretching, etc.) are like the dessert. Too many times coaches think that the dessert can be the main dish, disregarding what is really important for building the performances.