Originally Posted by FrmrSpecialist
I do about 5-7 marathons a year, if your knees are "acting up" get your running form analyzed... you are most likely a heel striker which will cause you to need hip or knee replacement in the future. Get it evaluated and get the right shoes on.. 20 miles a week won't cut it unless your goal is to just finish. But if you want to recover fairly decently and enjoy the run slowly ramp up your miles following the general 10% rule ( your weekly mileage increase shouldn't exceed 10% of the previous week) same applies for your long runs... your long runs are the days you really push your body and are done usually once a week till you get to higher mileage (+15 miles) then you alternate your long runs every other week. Your long runs should also be at 1-2 minutes per mile slower thsn your marathon pace. Keep increasing your long runs until you hit roughly 20-21 miles.. you want to hit that point about 2-3 weeks away from the marathon.
Bam! I'm also a marathon and I'd follow the advice stated above. I'd also pick a certain marathon about 5-6 months away, commit to it and sign up! That's also some added motivation for those long runs. Lot of marathons now also have training runs on the race course every weekend. That's a good way to get connected with other runners and pick their brain about anything. Good luck!