Russo22, when running remember "Big Elbows." When you get to that point in your run, usually a fast paced one like the PRT, where your legs begin to feel like Jello, and you feel like a 'wall' is pushing against you... remember use Big Elbows. I was taught this in high school track. I ran the Open 400 and the 4 x 400 relay. I always felt like Poo the last 75 meters, and my coach would yell out "big elbows."
What happens is when you begin to 'sag' in your run you lose your composure. Run tall with your shoulders up. You start making short steps with your feet because your legs feel twice as heavy. You also start to lose power in your arms. Believe it or not, you don't just run with your feet only. Pump your elbows back as far as you can. This will feel like you're a retard I promise, but no one will notice cause your hitting that wall. Throwing your elbows back instictively brings your knees up higher which in turn lengthens your stride. The longer your stride the least amount of steps it takes to get to the finish line. Mind you, you should only do this in a timed run such as the PRT when you've given all you can give. Don't start off your easy 4 miler like this or you will definately turn some heads, and not in a good way. That's my coaching tip for the day free of charge. Good Luck.