I'm doing sprints, hills and distance runs on various days.  I've improved my time, but I'm wondering how far I should push myself when I'm doing distance training.  

Should I go at an easy pace enough to complete the run (4-6 miles) or push myself till I'm exhausted?  I do it at an easy pace but am I cheating myself?  Is it simply completing the distance that counts?

If you can run 4-6 miles then the 2 mile run (I assume for the military) should be a cake walk! It will be 1/2 to 1/3 the distance you are capable of so "turning it on" for a faster time in 2 miles should be no problem.

Quoted: If you can run 4-6 miles then the 2 mile run (I assume for the military) should be a cake walk! It will be 1/2 to 1/3 the distance you are capable of so "turning it on" for a faster time in 2 miles should be no problem.

I complete the distance but I stop a few times or shuffle my feet to rest.

I did a mile today and shaved 2 minutes off.  Three weeks ago I did it in 10min now I'm down 7min 54sec.  The workouts are paying off!

For over 1.5 mile runs run at the lactate threshold.  Run till your legs start to burn then back off and keep it there right at the border line of burning.  There is a direct corrolation in improvment till you hit about 50 miles a week. Do more miles per week till you can do 50 miles total running a tthe lactate threshhold the entire run. At that point you should do more interval work to be more time efficient rather than run more miles or more times per week.

Again assuming you're training for mil 2-miler - how long till you have to do it?

There are some good folks over at Runner's World .

Quoted: Again assuming you're training for mil 2-miler - how long till you have to do it?

I have a few months till the test.

Sounds like you have a good combination going there. How many Miles a week are you getting in? Also how many days.

Dont forget to throw in a couple 2 mile repeats. One day go out and un two miles like its a race. Walk for 10 minutes get your heart rate down and Go at it again.  It will kinda like a test run day.

One of my favorite workouts for speed goes like this. 2 miles easy, nice running pace, I can still talk comfortably, Then the next two miles, One minute sprint, one minute easy jog, on and off for the two miles. Then an easy 2 mile run.

6 miles 5 days a week and when you can do that at aound 8:00/mile pace then change 1 day to fartleks for 1 mile and build up to fartleks for 3 miles over a couple months. The day after fartleks should be a very slow pace run or cross-training or even nothing. That helped me get my time down but it took alot of months.