I am a 53 year-old man training for my first marathon. About 4 years ago I had surgery on my left knee for some old sports injuries. The results helped with mobility but did not address the arthritis that often makes it difficult for me to walk any distance even today. My lack of exercise and careless diet was leading to high blood pressure.
Out of concern for my heart I decided to start running despite my knee- I figured that a healthy heart was more important to my overall health and was worth the risk of further knee damage. What I have discovered has surprised me, my family, and friends. A little over a year ago, I started jogging. At first, I couldn't go a mile without stopping but I realized that the knee wasn't as troublesome as my stamina. I found the same to be true on subsequent runs of longer distances. I continued to run 2-3 times a week and got up to 2-5 miles on average.
I ran six 5Ks in 2007 and always finished well in my age group. After a year of running regularly, my knee doesn't feel any worse than before and my blood pressure has improved significantly. Recently, I decide to go for a long time dream of running a marathon, something that I had pretty much given up on a couple of year's ago. My longest run is about 11 miles and I have a little over 2 months before the event. My 5k times are in the 24-25 minute range and my long training runs are at about a 10 minute/mile pace. Last week my total training mileage was 25 miles.
My questions are:
1. Advice on training?
2. Anyone with similar experience with arthritis?
3. Is hitting the "wall" unavoidable? (what I've heard concerns me)
Thanks, georgeandpat.

Congratulations on some fantastic progress! Given that it's two months before your marathon, it's too late for any real training advice - that needs to come 6 months before. You've got perseverance and desire, both of which will get you through. Given that your longest run to date has been 11 miles, it sounds like you're not following any structured training program, which is fine, but you'll just have to be careful not to end up with an overuse injury, which is common for people who ramp up quickly to a marathon. The wall is not inevitable with proper training and good pacing, but I would say you are very likely to experience it because you don't have a big training base and you won't likely get in a sufficient number of 20 mile runs to build up the endurance and fat-burning efficiency you will need to avoid it. Can't answer about the arthritis, but perhaps glucosamine/chondroitin will be a helpful supplement. Make sure that your pace on your long runs is such that you can sustain it through the entire run without being terribly drained at the end. If that's not the case, you need to slow it down a bit.

Formation flyer, Thank you for the feedback. I have been taking glucosamine chondroitin and have implemented other measures to minimize the impact of running on my knees. I know I should have started training earlier for this but I felt the time was now as I'm feeling pretty healthy these days and may not have another opportunity. georgeandpat.