SO many things wrong here:

-Running 2xs a week makes you essentially a "weekend warrior" this will set you up for injury.
-Running without weight training is foolish and will set you up for injury. You should be spending 20 minuets before bed doing leg exercises. Mainly various forms of squats, RDLs, split lunges, and ideally balancing on the BOSE ball. and then you should do 10 min of abdominal work.
-IF you incorporate strength training, in order to increase your speed, you should do running intervals for 30 min.

I started out like the OP as far as a beginner. Due to a lot of injuries, I had to quit running and focus only on strength training, as my body could not take it, I was running 10 min miles. I did strength training for 3 months-HARD and then I felt better and ONLY did interval runs 3xs a week for 30-40 min at a stretch.

I then ran the DC marathon last March with ZERO distance training, just the strength and the intervals. I finished it with hardly any effort at 9mm pace which was a PR. I probably could have done 8:30 and been spent.

I will never go back to boring long runs. I'm personally much better off in the gym and doing intervals on a treadmill. I do however run outside once a week, gotta keep those stability muscles working, though I do think the BOSE ball fills that gap.

Hi intensity interval training (HIIT) might help you break thru....

also you wrote "One other note -- other than being active with my kids, I do no other exercise other than the run"

That's probably a mistake for you (at your level, or any level for that matter)... I would wager that a bit of weight training would help you TREMENDOUSLY... squats (and/or deadlifts) ... hi-intensity core work (regular planks and toe to opposite elbow planks)... to name a few.

and because all you do is run... I'd wager that you are less flexible and stable in your hip adductors and abductors than you need to be ...

Hope you find it useful.

What really helped me was having a set goal and small incremental increases to get there. Earlier this summer I worked up from <3 to >5 miles over the course of six weeks or so, at about your pace. Every week, I increased my mileage by 10%, and then dialed it back every third week for a recovery. That 10% increase was overall mileage for the week, and also the distance of my 'long run' which I would do once a week.

If at all possible, I'd aim for at least 3 runs a week: one short, one medium, and then your long run. So if you're running 6 miles/week now, run 1mile one day, 2 miles another, and 3 miles for your long run. Next week, run something like 1.3, 2, and 3.3 miles for your long run, for a 10% increase. You'll be up to 5 miles in a few weeks, and the increases are so small that mentally very easy to make it through.

OP: look at this information from Runner's World, it might be helpful.

http://www.runnersworld.com/beginners/have-i-reached-a-training-plateau?cm_mmc=Twitter-_-RunnersWorld-_-Content-Training-_-TrainingPlateau

I'm surprised everyone is saying just to increase distance. That will just make you slower--even on your shorter runs. To increase speeds, you need to do some interval training. Run fast a block, run slow a block, or add some short runs where you really focus on speed. Or run some hills.

If your only goal is to increase distance, then just add distance, but you'll probably become even slower.

What about adding one or two interval runs and one longer run to your routine?

Twice a week is simply not enough. You need to be running more often and more consistently.

Either increase your distance, or increase your speed. You don't necessarily need to run more often, but your gains will come slower if you don't. Recognize that no matter what you do, gains will come slower as you get better.

If I were you, I'd keep running the three mile route, but try to run it faster each time. Wear a watch, and make it your goal to beat your previous time by at least 10 seconds.

Report back and let us know how it goes.

The problem is you are only running twice a week. You need to run at least 4 times a week. You are building up a little fitness and then losing it. Once you get up to 4 days a week you can start lengthening one of the runs but at 2 days a week you will always be a little out of shape for each run.

For what it's worth, I had the same experience, and felt stuck at 3-4 miles for a VERY long time. I think I was afraid to try to go longer and fail. I felt "spent" after running 3 miles and wondered how I'd ever be able to go further. That was six months ago - on Sunday I'm running the Army Ten Miler and feel genuinely ready to do so.

The keys to breaking the plateau for me were to incrementally increase my distance on a set schedule (I gave myself permission to walk if I needed to, which I did in the summer when it was really hot and miserable, but no matter what, I covered my set goal of X miles); to vary my distances, pace and routes so my body didn't get used to a set pattern (e.g., today I will run 2 miles under 10 min mile pace or do 5 miles at any pace); and to start running with a friend who had similar fitness level/goals (so we'd go out together with the goal of running x miles together). I've also learned that I really like trail running (i.e. in the woods on a dirt path versus a paved surface). I also found that using a tracking program helped keep me motivated - I use RunKeeper but I know there are others out there.

My next phase is to work in strength training and more speedwork. I'm not sure I want to run more distance at this point, but would like to see if I can bring my times down.

Good luck - you can do this!!

Agree with PPs to slow it down and focus on distance. Also try doing 2 shorter runs during the week and a longer run (start with 4 miles?) on the weekend.

Definitely focus on distance over speed. I would also suggest adding in some basic weight training to build your leg muscles.

You'll need to run more than twice a week to break through. More like 3 miles 4xs a week and then increase your mileage. I find I have more stamina if I set a route for myself rather than just running anywhere. Try mapping out a 5-mile route and run/walk it until you can do the whole thing running.

Try finding someone to run with. That always helps me.

Slow your pace to go farther, since that pace is still tough for you at 3 miles. If you can add some distance (even if it's slower) it will be a confidence boost. Speeding up will come with more time.

I'm a new runner.. I tried starting with a couch to 5K.. that was too easy for me, so I just started running as far as I could, walk a bit, then run more. it's been 3 months or so... I'm at 3 miles straight running now.. at about an 11 and a half minute mile... but I can't seem to get past that point. I've been doing the 3 miles, at that pace for over a month now. And I'm still in the phase where the entire 3 miles is pretty tough.. each day I never think I'll make 3, but usually do.

I try to run 3 times a week, but most weeks it's just two times. What should I do to break through? I want to get a little faster.. but speed is not my main goal. And I'd like to stretch it out eventually to 5 miles.. that's my target. I don't envision ever wanting to go more than 5. What should I be doing?

One other note -- other than being active with my kids, I do no other exercise other than the run.