Thoughts on a Sub-4 Hour Marathon

I've found myself in a bit of a conundrum lately.  Now that I have officially started marathon training, I find it is important to solidify my goal.  My first marathon was great—I enjoyed the experience and I finished.  But, I went out too fast, fell apart in the final miles, and ended up with a time less than ideal.

But I'm ok with that.  That experience has caused me to approach my upcoming marathon not as avoiding the failure of last time, but as pushing myself toward a new and more exciting goal.  I initially set this new goal as "run a marathon in less than 4 hours".  Why 4 hours?  In my mind, 4 hours separates the plodders (a group of which I was proud to belong to) and everyone else (which I hope to become).  My intent is not to demean those who run a 4+ hour marathon, but I think it's important to set goals that push us ahead.  I feel that 4 hours is attainable for me, and that's my goal.  Sure, it involves taking almost 50 minutes off my last marathon time, but if I work hard enough, I can do that.  There lies my conundrum.

I've been training hard.  I've done intervals.  I've done tempo runs.  I've ran so many hills that my vertical distance is probably close to my horizontal distance.  Because of all this, I'm in great shape, and I'm running stronger and faster than I have at any time since high school.

So, what do I make of this?  Well, using fancy gizmos known as running calculators, I decided to see if I could predict my marathon time.  I put my most recent race (22'06" from the Brian Kraft 5k) into these calculators, and this is what I get:

McMillan Running: 3:35
Runworks.com: 3:31
Runner's World: 3:32

So, all 3 say I should be able to run a marathon in about 3 and a half hours.  Sounds great, right?  Well, a caveat is that it's hard to predict a longer race from a short race like a 5k.  But, even if I add 10 minutes to those predicted times, it's still in the 3:40 − 3:45 range.  In marathoning terms, that's a whole lot faster than 4 hours.

Can I run a marathon in 3:45?  I don't know.  What I do know, however, is that with a goal of 4 hours, my training paces are slower than I think they should be.  To train for a 4 hour marathon, I should do my long runs somewhere between 10 and 11 min/mile, and my marathon "pace runs" at 9:09/mile.  Comparing that with what I'm actually doing, I haven't run slower than 9 min/mile since early April.  Ratcheting myself down to 10 min miles might not even be possible right now.  I do understand the importance of going slow on the long runs, but 9:30/mile is probably as slow as I'd like to go.

What do I do?  I don't know.  I think I'm going to shift my goal to a 3:45 − 3:50 marathon and train based on those paces to start.  I may also enter the Red, White, and Boom! half marathon on July 4.  I've never run a stand-alone half, but I feel like it would be a much better predictor of what I'm capable of than a 5k.  If you've got any suggestions, though, I'd love to hear them.