Why some top-level sprinter are many strength in the full-Squat and Benchand others no?
The speed isn’t daughter of the Force limit?
Bump!!!
No, she is only a step-daughter. 
If you are asking if a big squat or big bench is needed to sprint fast the answer is no. Yes, speed is strength related, but that strength can be expressed and developed in different ways (plyos, med-ball, resist-runs).
And what’s the relation between maximal strength and speed-strength/explosiveness?
Up to a point, the development of max strength will enhance speed strength and explosive strength. However, with respect to speed strength sports, there comes a point in which the difference between maximum strength and the force which may be applied during the sporting action becomes too great. This would be classified as too large a percentage as indicated by the explosive strength deficit. Thus, further increases in max strength would cease to faciliate improved sporting performance, and the training emphasis must shift to decreasing the explosive strength deficit.
Put simply, with respect to sports in which power/speed strength/speed are the dominant motor requirements, there comes a point in which the further development of max strength becomes futile. However, the majority of athletes who participate in these types of sports are a long way away from attaining such max strength levels.
Back to the original question:
1)Why some top-level sprinter are many strength in the full-Squat and Benchand others no?
2)The speed isn’t daughter of the Force limit?
-> 1. Different morphologies and natural abilities, different training methods. Some world class sprinters even never benched or full-squatted (but use other exercises of course) !
-> 2. No, speed is daughter of power, and power is sister of force limit or maximal strength. However, sprinting is more complex than just speed. Sprinting improvement comes along strength/force improvement, but also with improved running technique, health/medical, mental, personal life and other flucuent factors… Decade after decade, it has been evident that at world class level, sprinters with better max strength weren’t better starters than “weaker” sprinters. And start is just a little part of 100m running, so max velocity and speed endurance have even less to do with max strength.
Anyway, few coaches and sprinters train for max strength, even when we look to golden oldies like in USA with Bud Winter’s athletes, in Germany with Armin Hary, in France with Joseph Maigrot’s athletes, in USSR with Valeriy Borzov, etc… Manfred Letzelter mentions in his force training book that an inquiry concerning the best 30 FRG sprinters revealled that only 10% of them used max strength training.
jman -
I don’t quite understand this. If improvement on one part of the strength curve affects all other parts of the curve, then shouldn’t improvements on the strength end always cause improvements in speed, no matter how high max strength levels already are? Obviously I do agree though that athletes with high levels of max strength and low RFD should do more RFD work than strength work.
Yes but only an INCREASE in the POTENTIAL to generate great speeds. You have to realise your potential by doing the correct things at the right time. Hence the fact that Max St training is reduced and then maintained in CF’s training (annual plan) and Bompa’s periodisation plans while other aspects (speed endurance and speed) are developed.