Ok, so this year I am tackling my first sprint duathlon (late April) and a couple of century rides, too...in addition to running a 25k, a trail relay, and a couple of half-marathons.

What I'm "running" into is figuring out how to set up training plans for these things. Even the more difficult plan I have for a sprint du is assuming that a person is training ONLY for that race...but 2 weeks after the du I will be doing a 25k and I think the longest run that du plan would have me do is about 6 miles. Training for my first century ride in the Summer and a HM a month later also has me scratching my head at how I should proceed.

I put together a rough-draft training plan for the duathlon, including training for the following 25k. At least one of those weeks would have me working out for 12 hours that week. Granted, I know time on the bike will be less of a physical toll than the same amount of time running...but TWELVE hours? Seriously. My concern is that my body is going to say "f you!" I think my max week training for my last marathon was about 10.5 hours of training...and I was feeling a little beat-up and burned-out by that point.

So what do you all recommend? Cutting back a bit on the running mileage? I had hoped to hit 1500 running miles this year (had 1800 last year, but without any substantial bike miles), but now wonder if I might be better off simply setting a goal of 100 miles on-foot each month. I'm guessing that the time on the bike can substitute for some of those short recovery runs, as long as I am still getting a long run and some mid-length support runs...is this right?

Thanks in advance for any insight/advice.