How do you deal with performing much worse than you hoped to in a marathon?

My best advice is enjoy the build and dont think so much about the end result you desire. Ask yourself this: are you confident you are getting fit and getting the right training stimulus during the build? What part of your race did you struggle the most? How can we adjust our training plan to fix that? I went almost 4 years training for a 10k and failing to PR until I finally did, and I now know for the future what I need to do correctly to keep progressing. You will do fine as long as you compose yourself and dont let 1 bad race define you.

Ask yourself why do you NEED your marathon PR to equate to the other distances? If the possibility of failure (or less than an ideal race) is so frustrating why force it? Just do what you enjoy. And don't apologize for doing what you enjoy either. Let's short, have fun training and racing.

Now if you come to the conclusion that you really do want your marathon PR to be something you personally feel is respectable, then accept the risk and deal with it.

Your post tells me that you do not know how to properly train or race plan. Get a coach.

1. Enter a shorter race like a half or 10 miler a few weeks out from the marathon. A good race here will make a crappy marathon sting less.

2. Analyze your training - be honest with yourself - did you really do what was needed for a good marathon. Some people are super talented and can run a respectable time on 40 mpw. Others won't ever get their marathon pr in line with their other prs no matter how much mileage they run. But you can look at your mileage, how much running at mp you did, etc. Chances are a respectable marathon takes a lot more work than you think it should for someone of your talent level.

3. Run more. If you aren't running over 140 miles a week, running over marathon distance in long runs a few times a season, and routinely running 15-18 miles at marathon pace in runs over 20 miles, you can be doing more.

4. Analyze your race - were you honest with yourself about your abilities. Did you go out at a pace relative to your current fitness level, not the fitness level of the pr you hoped to set.

5. Read the 5 key marathon workouts thread

6. If all else fails, peak for shorter distances. Right now everyone over age 22 hypes the marathon, but if you can tune that out and train for the half or a track 10k, there will be no worry that your marathon time isn't too good.

Marathon running is hard, very hard.

Once you reached your highest level, it is very difficult to get faster and any result which is 2 minutes slower is disappointing.

Some people start doing ultras for that reason, others stop running altogether and them others , usually not that fast just start collecting Marathon races.

Good luck with your choice.

There's nothing here to deal with. There's nothing here to come to terms with. This is all just psychological masturbation. The race is done. Another race is coming up. Do better in that one.

There's no way I've reached my full potential. I'm 25 with 2.5 years running, and I'm still hitting PRs on most every race under marathon right now. 18:46 5k and 1:28:56 half marathon are my PRs, both within the last 3 months, and I really don't know what my capabilities are yet, trying to figure it out. I know my marathon pace isn't supposed to be as fast as my half marathon pace, but 2 minutes is a pretty massive gap there. I do really enjoy 5k races though, and there's definitely a case to be made for me to get what I can from them before I hit my 30s, and then try marathons again once I plateau there. For some context on my 5k time, I didn't really try racing them until last October, and I dropped about 1:45 from then to April. Haven't raced one since, but since I took time off in May when I went to Italy and it's so hot now, a PR today might be tough, but hitting one in the fall when things cool off shouldn't be.

2.5 years isn't enough before taking a crack at a marathon. You've got lots of potential left in mile-HM distances. Do a few more rounds of that.

Don't even think about another marathon build until fall 2025 or 2026. You just need to learn more about running in general, and about yourself as a runner, and about the odd specifics of marathons, before giving it another go.

if your half marathon pace is really 2 minutes per mile faster than your marathon pace that means you have run 1:28 and 3:48 -- wow. Something very wrong there.

3:50:5x for the marathon, so even slower. The half marathon is much more recent, so that probably has a lot to do with it, but I had a 1:37:xx half marathon prior to starting the marathon training. Both attempts at the marathon I crashed HARD at the end.

Yeah, hopping on the marathon bandwagon is what got me into running, but I've seen value in shorter races I didn't see before. I do really enjoy 5k races, so I may as well push for sub 18, and then see if I have 17:30 in me because why not. My mile is also weaker than my 5k, at 5:34 compared to 18:46, so giving that a go could be fun too. I just hate how bad my marathon PR looks compared to my other ones, but that is just a dumb ego thing rather than a real love of marathons, so maybe I could just get over that, especially since I'm not really fast enough to have an ego about anyway.

The guy has to up his mileage and do more long runs, with some MP in the long runs, I agree.

But running 140 mpw ??? Running more than marathon distance in training ???

The guy is a 1:28 half marathoner, not a pro.

Consistently running 40-50 mpw may get him a long way.

I didn't know that when I made the post. For him maybe he needs to get to 70 now and do more 20 mile runs. The principle applies.

I don't think any pro has a marathon PR minutes per mile slower than half marathon pace, unless you count DNF or DNS as "PRs". But I'm certainly well under 140 mpw, so I guess that means I fall into the "could do more" category

Out of the 16 marathons I did, I would only say that five of them were keepers. Two were disasters and almost DNFs. Most were bonks of various degrees where I was on pace until the last 6 miles and lost my race goal shuffling it in. But the bad races only made me want to get back into training and try again. And ultimately, I enjoyed the process much more than the results. It is frustrating to put in the work and then have everything go to sh$t on race day. But those twenty milers add up over time. And unless your training is crappy or your race pacing is off, you will get some good results.

You should not consider 3:50+ a representative time for your marathon. Sounds like you undertrained for the mileage, crashed and maybe walk/jogged for several miles at the end?

And maybe you started out too fast (I'm projecting here)?

Did you follow a good plan like Daniels or Pfitzinger? If you can nail the workouts in those plans then the only thing stopping you from success is going out too fast ("I can run this fast pace all day") or bad weather.

Wow, did I write that and forget? All of that is the same experience and outlook that have.

I no longer worry (too much) about the result I want. I figure what's the worst outcome - I'll just improve my fitness?

Out of curiosity.. besides the OP, how do all of your half marathon PRs compare to your full marathon PRs? My marathon PR is 2:42 from 2018 and I ran my half marathon PR of 1:15 in 2019 (NYC marathon and a relatively flat Long Beach half marathon). Marathons are much harder than IMHO with much more chances of something bad happening but stick with it and you will improve your marathon time significantly. I improved from a 4:12 marathon in 2016 through consistent training and racing a series of half marathons.

There's a possibility that things will go wrong, but that possibility is increased to around 99% if you don't fuel throughout the marathon.

1 gel is ridiculous; you're just setting yourself up for failure.

I had the equivalent of 9 gels in each of my last 2 marathons, and performed exactly as expected.

Most of the underperforming in marathons is the result of poor fuelling, hydration and/or pacing.

Get those 3 things right, and you'll have eliminated almost all of the uncertainty.