Yea. This past week I ran Sunday, Tuesday, Thursday, Friday. Yesterday's run was alot a 6.2 miler at a pace that hadn't been seen since XC. Thats the danger of the treadmill.
So today its an cycling day. See what happens tomorrow on the trails.

I usually go 6 days a week, 8 runs, but I've been at it for awhile and injury free for over a year... knock wood. I know most only recommend 4-5 running days per week for triathletes, but hey, I do love the runnin' and because I can... I do.

I listen closely to what my body's telling me though and have no problem taking a few days off if I start feeling something goin' south. I'm not really going to lose any base and the rest does a body good if needed.

When I do need to fill in gaps, I'll concentrate on my weakest link, swimming at the moment, and get in some extra strength and core training.

I think you said it best in your post "slowly building" is the only way to go. Everyone's different, work out what's best for you to keep yourself injury free.

As for being sane...:D

The number of runs a week really isn't the issue...it's the quality of those runs. You can run very effectively on 4 per week as some folks here do...Long,speed,tempo,easy. Any more than that and you risk injury...Simply look at all the threads here where folks talk about injury...running too hard, too often,increasing milage too fast...no rest days..running hard bricks.
The key is to be consistant with the quality and not fudge the long runs... really do them at a relaxed pace. Too many folks do their long runs hard and there's the devil to pay if you do that for too long.
There is no formula,Al...ya have to find what works for you.
Saying "What do you do to compensate." implies that it's not good to be running only 4 times a week...
In fact, if you ran fewer times a week, but ran your miles smarter, your running would improve.
Biking is key....Good quality miles on the bike helps with running. You can safely replace some of those extra runs with time spent on the bike...as long as you aren't mashing gears and trashing yourself constantly.

I am currently following the IM training plan available at Trifuel so I am running 4 times a week. The only change I have made is a long run buildup on Sundays for Bosotn.

I thought I would have a tough time not running 6 days a week but I feel better than I have in a long time. So many of the aches I had in the fall are completely gone. Plus I am loving the bike, even though it is on the trainer. I have never done the drills before and I am feeling stronger each week.

There are no completely off days because of light lifting and core work.

I usually run 3x a week. One long (up to 2 hours) and two sorter (usually an hour or less.) During the build periods of my season, those short runs are pretty intense. With all the riding I do, there's no real point in running more. Make it quality time, and stick to 3 or 4 days.

I run 5 to 6 times a week...with a long run up to 2 hours...
I agree with Anton depends more on the quality of the runs...more than the frequency....sometimes just for pure amusement I will go an extra day of running....

Al -- I'd say it's time to find your love for the bike, or get on a mtn bike, or go for a hike. There are other ways to enjoy that part without the risks, and you've been injured like crazy this year. I come from a running background, and it took time to realize that the other sports can bring just as much enjoyment if you let them in. It's part of what kept me in tris... else I would have gone back to just running if I didn't enjoy the other parts.There isn't just a runner's high but also a biker's high, swimmer's high... oh let's just call it a trihigh :)

How many runs per week is like asking how long is a piece of string. Having been in this sport for 20 years with varying degrees of personal success the question is what are your race plans and what is your training plan to get the best result. Running comprises about 30-35% of most races but is the most
stressful of the three sports on the body. Yes, it is the most physically/mentally satisfying aspect but one must learn to keep their eye on the prize i.e. a personally satisfying race result.
To be successful year in and year out you have to have discipline to keep the engine running on all cylinders. Too much of this and not enough of that makes for an injured athlete.
Runnig ten times a week is mentally and physically unhealthy for a multi-sport athlete. The body become fatigued and subsequent workouts are junk miles. Try 3-4 quality runs with purpose.
Training with a plan and a goal and staying focused on both is shows maturity and culminates in a good outcomes.
If logging 70 miles a week running is a goal then do it. If finishing in the top third of the field is a goal and running 70 miles a week is making the body too tired to be in the top third then it is time think.