Lindsey: I ran the Ascent in 2011 and was in full swing to run the Ascent again last year when I got injured. I've been to Manitou Springs 3 times now to run the Garden of the Gods and train on Barr Trail.
You will need to get in some trail time to get used to running on uneven surfaces. As far as trails go, Barr is relatively non-technical but to pass people on race day you have to run the fringes.
The 1 & 1 suggestion is right from Matt Carpenter - see his web site. Try and do a tempo run on the treadmill and either vary the pace or incline such that you run for 1 minute at 5 beats per minute above your threshold or lactate balance heart rate with the next minute at 5 bpm below threshold. Work up to doing 40 minutes of this.
Some stair work or steep power hiking is also advisable.
Laslty if you can - find some altitude. I've been to the top of Pikes 5 times now and hiked the Nevado de Colima (also a 14er) twice and while the effects are reduced, I still feel the altitude.
Cheers and enjoy - this is an awesome event!
In response to:
Thanks so much for the input Milton. I took your advice and ended up putting together a plan with hills, trail runs, running some awesome stairs near where I live, yoga, incline treadmill runs, and regular old flat runs. Last time I ran PPM, I did a couple treadmill simulations of the ascent and will do that again as well.
In response to:
You can follow a typical marathon training program with a couple of exceptions.
1) Add a little time to your long runs. Consider how long you think it will take you to finish and go from there. However, the time might be skewed, comparatively, for front-of-the-pack and mid-pack runners. It would be beneficial for a 5-hour Pikes marathoner to run a 4-to-5-hour long run in training. It wouldn't be beneficial, in my opinion, for an 8-hour Pikes marathoner to run an 8-hour long run in training. You might want to consider anywhere from 4 to 6 hours for a peak long run (with walking of course) regardless of your expected finishing time.
2) You have to train for strength. Once a week, do body weight leg exercises like air squats, lunges, box jumps, etc. Add a weight vest if you're advanced. Also once a week, try to run a hilly route at a good pace, either tempo run/intervals or fast hiking.
An example week would be Tuesday run an easy run and do leg exercises, Thursday run hills, Saturday long run. If hills are minimal in your area, use the treadmill. I'll go to the gym and run 3-4 miles outside, go inside and hop on a treadmill with the incline at 12% and run 30 min either tempo or 1/1 intervals, and go back outside to do a 3-4 mile cool down.
Apart from strength and more endurance (ability to stay on your feet), it's just like training for a regular marathon.