I play quarterback, so speed endurance is most likely not limiting me. However, I guess I was indirectly referring back to my days on the track. I was quick for 20-30 yards/meters, but then would gradually taper off.
Last summer in preperation for my football season, I ran a lot of 40s, 30s, 20s, and 10s… I also did some bounding, horizontal and vertical jumping, speed hops etc. I felt like not including any overtraining I never got in very good shape.
When the time came for me to run my 40 at camp, I was actually tired from the warm up our coach had us do, and I under performed. I ran 4.87, I was shooting for the 4.7s which I had run a few times that summer.
My '09 track season in a nutshell went like this: Preseason: worked speed- was getting faster. Season started- torn groin muscle… limited work for a month. I continued to squat heavy because the groin gave me no problems. Once I was healthy, I continued squatting- but my times were suffering. My times slowly got better as I got back into shape, but then they remained the same. So… I stopped squatting… and my times dropped dramatically. I was running much faster than I ever have. So, I automatically assume that I should stop squatting when race day approaches + back pain = I don’t squat the rest of the summer. Just speed work.
Now, post football season: I squatted from november until feb. My back hurts again. I didn’t have any problems when I wasn’t squatting. I have stopped squatting, but haven’t gotten back into much speed work, just been playing a lot of basketball 
Now I am excited to get back on the track. Squatting again if I must. I have not placed any emphasis on endurance training in the past and only a little on plyometric. I basically have just gone out to the track and ran 20 or so short sprints.
I think I will look to purchase CFTS. Sounds like its worth it-- make sure I am doing everything I need to be to be getting faster!
Thanks again