How can I run faster?

For the last previous 3 Night Moves, I've been able to be a minute faster. My first run: 11 min mile, second run: 10 min and then third: 9 min. My last run lastnight, I came in again at 9 min. I was really upset. I was hoping I could run an 8 min mile. Was it because I went out the night before and had too many vodka tonics? I just wasn't in a running mood and I had stomach cramp half way into the run.

So I perused on the web and found that I need to work on my Speed Endurance and the 3 factors that limit them:

V02 - is the maximum volume of oxygen you can use per kilo of body-weight. Can be improved a bit through losing excess body fat (hence my spin classes three nights a week) and V02 Training .

Lactate Threshold - Lactate is a by-product of the process of burning energy to fuel movement. Lactic Acid produces energy and carbon dioxide when mixed with oxygen. As you run faster, the greater the rate of lactate accumulation.At some point as you increase your speed, the lactate concentration in your muscles and blood stream will become so high that your muscles can’t operate, and you start feeling pain – especially in the quadriceps (thigh muscles).And no matter how hard you try, you can’t increase your speed.

Running Efficiency - improve your efficiency through working on your form

As I was attempting to run faster, I was breathing faster and before I knew it, my legs started to give out. My thighs were hurting and no matter how much I tried to force myself to run faster, I couldn't. So I slowed down to a walk (cramps) and noticed that when I started running again, I no longer felt the pain as lactate clears quite quickly if you slow down or stop per the article.

hmmmm.... but surprisingly, I read another article which countered the previous article. This article states that lactate was not responsible for muscle fatigue:

"lactate is actually an important fuel that is used by the muscles during prolonged exercise"

aaaarghh..enough reading. Well, I have two more night moves (5K) to run before the event is over. I am going to work on some interval training and short sprints. If I can finish the event with an 8 min mile, I will be content.