Long run confusion

To follow this rule and get a 20-miler in, one would have to have an 80-100 mile week. I've never had an 80-mile week in my life.

Re-check your sources. The rule of thumb, I believe, is 50%.

I can only tell you from my experience training for two HMs, and I increased my mileage pretty quickly.  I am no coach, etc., and consider myself a beginning runner, with all of that in mind.  I used to get injured too if I ran too many days, but then I changed my cadence (increased) and those problems seemed to go away (I've run the last 5 days straight, total of 22 miles, no adverse effects).  Everyone is different

You have to get out there and run at least the amount of time you expect to be on the course, plus a little more, at least a couple times (IMHO).  SO that would be close to 12 or 13 + miles.  I imagine you are not running 26 mile weeks, or won't be (my biggest were in the low 20s) so I really don't see a way to not do it having the long run equal 50%. 

The other alternative you mention, increasing the shorter runs, is, again IMHO and as you state, a recipe for injury.  I think doing a week of a 12 mile run plus 2 8s, unless you're WaterDog66, is pretty hardcore.  Just from your post it sounds like way too much.  I think you need to have a long run, a tempo run, perhaps hill repeats or some other type of run, and an easy run.

Again, this is just my amateur opinion.

First, I must admit that I have read NONE of these web pages (except the one from the BT forum), but I was doing a google search on the subject:

http://www.rhoderunner.net/training.html

http://www.everythingtrackandfield.com/catalog/matriarch/OnePiecePage.asp_Q_PageID_E_311_A_PageName_E_ArticleGardinerCrossCountry

http://www.aggiesrunning.com/Coaching/AggieXCTrainingSeptember2005/tabid/143/Default.aspx

http://www.beginnertriathlete.com/discussion/forums/thread-view.asp?tid=70396&posts=18&highlight=long%20run%2050%%20weekly%20miles&highlightmode=1#M739388

The last link from the BT forums is what got me thinking about this.  Here is the quote from our own JohnnyKay:

The "rule" itself comes from running experts like Jack Daniels, et.al., and was written with dedicated runners in mind.  Most marathon plans (at least for beginners/intermediates) will violate this rule as you stretch your long runs out because (as bear notes) most people are simply not going to do 75-80mpw.  Many beginner marathoners develop some overuse injuries or require long recoveries post-marathon (I did on both counts).  For triathletes, it can be very difficult to achieve while trying to balance swimming and biking along with running.

Its intent is to reduce injury risk and improve running consistency over a season (consistency, of course, being the key to long-term improvements).  If your long runs are 50%+ of your weekly volume, it is more likely that you don't have the base to be doing that safely (10% rule or not) for an extended period.

So I do think it is "better" to try to keep the long run at a more manageable percentage of your weekly volume, but realize it's not always practical.  I think for triathletes, the cross-training may provide enough benefits to stretch this to 30-40% (frankly, this is probably about where I am at least during tri-training season).  And perhaps even 50% is OK if somebody has enough long-term base or is done for a limited period (like getting in those 20 mile runs for your first marathon).  But I do think the risks climb as you push the ratio higher. 

This is all information I've gleaned from others (whose opinions I respect on these matters) and tried to incorporate in my own training to some extent.  Everyone has their own circumstances to work with though and may have to figure out what will work for them (hopefully without having to spend to much time figuring out what doesn't. )

Hope that helps some.

Thanks JK for chiming in on this!  (Especially since I quoted you.    )  Although I haven't read any Jack Daniels, my PT and I actually discussed just this point based on Mr. Daniels teachings.  But then I read those other mentioned plans and hence the confusion.  I think what you said makes a lot of sense.  Of course running 3 days a week, if every run was equal in length, then each would account for 33% of the volume.  In order for a long run to be a lower percentage, then one would have to run more than 3 days/week.

Most of this is just food for thought for me right now anyway.  I've just been running "normally" (for me) for only a month or two after battling achilles tendon problem.  How the heck does someone injure themselves running 3 days/week and no more than 10-12 mpw?  Neither my PT or my doctor really understands why it happened.  Whatever, I'm now running comfortably at 10mpw and am going to work up to 15-20mpw with my longest run being around 6-7 miles.  I'm not going to even think about changing anything for 6-12 months.  I'm just dreaming of things to come in the future. 

Diane