You are regularly running at least 2 or 3 days per week and, 6 months before your marathon, can currently run/jog for at least 60 minutes without needing to walk. The pace doesn’t matter, but this marathon training plan should get you to a training run before the marathon of something over 3 hours without stopping to walk. You might need to factor in some short walking breaks in the marathon itself but, broadly, we are looking at low to high 4 hours to complete the marathon.
At this level, the actual result will vary hugely depending on age, gender, weight, lifestyle, commitment to training and pace judgement (not to mention whether you are lucky or less lucky on the endurance genetics.) The pace details are less important than at more advanced levels and the absolute key factor is simply heading out the door (or onto the treadmill, that’s fine) more often and for longer than you have been used to doing. Developing some understanding of varying the effort so that you can distinguish between ‘ easy’ ‘steady’ and ’harder’ will also make life considerably easier.
For this level of marathoner, interval training is of far less significance than some articles may suggest (albeit it remains a useful part of the package.) You should be clear, however, that the midweek harder run is at a stronger effort than the weekend longer run. The long run should not be a scenario where every week you run as far and as you can as fast as you can, though some such runs are included. If you follow this plan you will finish somewhere in the middle of any large marathon field, mainly because so many will be much less well prepared than you.
The ParkRuns and 10ks are strongly recommended as milestones, both for motivation and because they will help guide you on pace judgement as you go up and down the endurance distances. Your marathon pace is not likely to be within one minute per mile of your 10k PB pace so bear that in mind as the marathon approaches. Think in terms of about 80-to 90 secs per mile slower than your 10k pace.
This marathon training plan does not show weekly mileage as it is all based on ‘time on feet’ and the paces will vary considerably among runners. No-one need worry that they have done ‘only’, for example, 23 miles in a week instead of a supposed 28 miles. If you are doing the time at the right effort level, that is just fine.
Note – do try to do these runs in the order shown, particularly as the long runs get longer. The idea is that you don’t push yourself too hard in the day or two before or after the longest runs, and that you are getting a well-spread variety of harder training efforts.