You did not ask any questions.  You just made a statement.  Your title makes it seem that you believe your training may be too much and cause over-training.  First everyone is different.  Some people can handle working out a lot, 10-20 hours/week.  While for others 5 hours/week may be too much.  A lot of outside influences (work, family, etc) can negatively impact your training.  Second you do not say much about your background.  Your previous experience will most likely determine how much you can handle.  4:30 for a 50k may be aggressive depending on your ability.  Third you do not mention your race, is it a road or trail race with lots of climb?  Some trails have lots of climb and 4:30 may not be attainable except by the elites.

IMO the schedule you posted seems reasonable.  But it would not be reasonable for a beginner with no running background.

BTW, where did you get this training schedule?  It is geared more towards triathletes.

James

How does one know if they are overtraining?

I mean if I could get away with it i would train 15-20hrs/week, but family and job prevent this(maybe that's a good thing).  Most of my running is on treadmill, because it's too dam hot outside.  I'm putting in 60-80miles/week, never run a marathon and thinking of doing one in Nov. It would be nice to BQ with this relatively flat marathon in Fla.  I frequently get gluteal and leg pains, but I just run through it with ibuprofen.  Anyway are there some more obvious signs of overtraining other than pure exhaustion?

Kayvon

Some references for you to check out. Dead give aways for me are huge increases in irritability, trouble sleeping, increased resting heart rate and decreased performance.

http://www.trifuel.com/triathlon/triathlon-training/overtraining-syndrome-000134.php

http://sportsmedicine.about.com/cs/overtraining/a/aa062499a.htm

zebUSCG - That schedule will be hard for you if you usually run 30mpw and your long run is up to 16 miles.  The first week already has two longish runs: 18 and 14.  Also the plan peaks at 50 mpw which would be a big jump for you.  Cut back weeks are used to allow your body to recover from previous weeks of hard workouts or increases in mileage; cut back weeks are not intended to minimize burn out. 

I am purely a marathoner that will occasionally do an ultra.  There are elements of that program that I do not like: too much XT (from a runner's perspective), taper is too long (4 weeks), last week is too low in volume.  Mostly minor quibbles.  IMO, most (non-beginner) marathon training programs will get you through 50k.

Personally I take time off between races to avoid over training and burn out.  Also I have no problems skipping workouts if I am too busy or tired.

James

Good info, James, thanks for sharing. I wish I would have found this earlier, I love Hal Higdon plans. In all honesty, I'm a Ph.D. student in an incredibly competitive program so I don't think I'd have time or energy (speaking about burnout: it's not just running-related!) to tackle 50% more mileage. Sure I'd be better trained, but I'd never make it to the starting line. I've upped my longest run from 26.2 to 31 and plan to run before/after my marathons. May go longer than that. My understanding is that physiologically the Sat/Sun back to back runs in either program serve as one really long run (i.e. 20 on Sat and 10 on Sun roughly equal a 30 miler).