A hot topic among marathon training runners is whether or not one should run more than 20 miles as their longest long run.
Oh the 20+ mile dilemma!
Here are my opinions on the matter and what I have gathered from helping other runners train for marathons:
If you are training for a specific time goal then I would possibly recommend doing a 20+ mile run at least once before the marathon.
If this is your first marathon and you would consider yourself a beginner runner you body is likely to become too stressed with a 20+ mile run and so you should skip it!
If you are going to need more than 3 hours to complete a long run then it would be best to save that for the marathon itself as you will be sustaining quite a bit of physical breakdown and you will already be sufficiently overloading your aerobic pathways at that pace as it is and that is the whole goal of your long run anyways!
If you are going to have to add on more than 10-15% of your total running mileage each week in order to complete a 20+ mile run then save that 20 mile+ run for race day.
Your risk of injury (whether major or minor) is too great a chance to take if your body is not ready for it.
As you can see with my 32 Week Marathon Training Plan I do schedule a 22-23 mile run because your training plan is so long and you are NOT increasing your long run distance every week but have reduced mileage weeks instead.
Depending on the research you look at, running over 20 miles does not give you added benefits to your marathon training.
One theory is that if you can run 20 miles then you will be able to add 6 more.
Those last 6 miles are going to be a mental and physical struggle either way but the fact that the finish line is there in 6 miles eases the burden.
Therefore, once marathon race day comes around you might have already reached and experienced your physical peak and be coming off of that and therefore not have your grand performance on race day.
There is a science to peaking at THE right time in order to have your marathon race day be your ultimate physical performance of your training period versus entering the race with a body that is slightly (or majorly) feeling run down and stressed. You want to be running at your optimal best that day!
This should be contingent though on previous mentioned factor: how that runners is feeling (enthused and motivated or ready to have marathon race day here and long training runs over with?), and if there have been any previous injuries along the way.
Schedule your last 20 miler or 20+ miler to be about 2 weeks before your marathon race date.
I really enjoy the confidence boost that I get with doing one 20+ mile run before the race itself.
Therefore I aim to do about 21-22 miles at least 2 weeks before the marathon.
To give you some perspective, I usually train for a marathon for about 4 months but my long runs start at about 6-8 miles, I am usually training for a time goal, and I regularly run each week before actually starting a training cycle.
This is the KEY! In the end, it will come down to you, your body and how you are wired!
And if you determine that in this marathon training time you are going to run 20 miles max or less - don't fret about it. Stick with your decision and move on!
I'll send you my free 24 Hour Timeline Checklist of Things You Should Do After a Long Run when you sign up!