Speed, Agility, and Quickness (SAQ) training has been a buzzword lately in sports performance training. There are some that say you can train for SAQ by doing certain weight training exercises in the gym that will translate to performance on the field.
A proper strength-training program will improve SAQ!
If you double the strength of the athlete you will greatly improve their Speed, Agility, and Quickness. Now to improve SAQ, that doesn't mean that strength training exercises are to be done fast. In the typical program, this is where "explosive training" (i.e. power cleans, snatches, etc.) would normally be used with the thought being "if you lift fast, you'll be fast". This is the LEAST productive type of training and the MOST stressful to the joints. Just yesterday in gym I saw 2 collegiate girls basketball players doing "power cleans". What power cleans have to do with girls basketball, I have no idea. What I do know is that it's a good way to have a severe injury especially for younger athletes that are still growing.
The quickest way to improve Speed, Agility, and Quickness is to develop strength throughout the whole body by doing a proper strength training program as outlined at FitLike51.com. Then go to your position coach and perform specific SAQ drills for your position. For example, a lineman looking to gain more explosiveness at the snap of the ball needs to practice the form and technique required for that action. If a wide receiver needs to improve quickness and reaction time, they need perform specific drills, mechanics of running, and timing on the practice field. No amount of "explosive training” or “power cleans” will improve their sports performance.