Good question. The lower you are to the ground, as at the start of a sprint or in a three point stance, as a running back, there little to no momentum to take advantage of.

Your leg muscles are also at their weakest position since the joints (hips, knees, ankles) will be at the beginning (or end) of their range of motion, depending on which muscle groups you are focusing on.

Either way, strength is all you have to work with at this point. This is where weight training has the best advantage to help, since you are training your body to overcome weight/gravity.

Once you are moving, in as little as one or two steps, momentum is created that becomes easier to take advantage of as you build speed. Also, your joints start to move away from their initial (or ending) position and this will enable your body to generate more leverage.

With regards to changing directions, unless your change is 180 degrees in the opposite direction, you will be able to take advantage of any momentum you have created. Also, you will probably be in a more upright position, and this enables other muscle groups to come into play to help improve your speed.

Our speed training program will help at the beginning of a sprint or run, but it is most effective when the body is more upright and has generated a little momentum to work with.

I have a question regarding the difference between “speed” and “power.” Does your training method also affect the initial power application at the beginning of a max effort run? For instance, I am a running back and I’m interested in reducing the time it takes me to accelerate to top speed after a change of direction. I figured that a good way to improve my initial power output was to run weighted sprints, but reading over your studies I guess I’m wrong.

http://athleticquickness.com/page.asp?page_id=91

It will give you some tips on how to continue with your strength training and include your speed training as well. As far as which stance your in, you can best decide that depending on what you anticipate will happen in the play.

http://speedtrainingsecrets.com/blog/speed-vs-strength/does-weight-training-have-a-place-when-training-athletes-for-speed.html

In addition, the idea that the “greater the force production into the ground the faster one would be” is widely disputed. It may appear to make sense at first, but on closer examination it begins to not make sense. Here are some conclusions from Harvard research study about the limits of running speed:

“What limits top speed, then, is the minimum time you take to swing your leg into position for the next step,” ….

“These results support the conclusion that running involves little active muscle power. Much of the work of running is done through passive mechanical processes, in which tendons and muscles act through elastic rebound, much like springs uncoiling,” Sternlight comments. “The uncoiling delivers the power to swing your legs.”

These comments support the idea that running speed is more a factor of the speed of your forward moving leg and not the strength of your backward moving leg. Which means that your thigh flexor muscle would be the primary muscle group involved in sprinting faster. (http://www.athleticquickness.com/page.asp?page_id=85)

You can read an article about this study here: http://www.hno.harvard.edu/gazette/1998/04.30/StudentSolvesMy.html

http://www.athleticquickness.com/page.asp?page_id=91

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