/ Brighton Marathon - Dehydration

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Euge - on 09:36 Wed

Morning All

I ran the Brighton Marathon at the weekend and had a bit of a mare from mile 15!!!

I was going for a sub 4 Hr and trained really hard for it, my previous Marathon time was Loch Ness  with 4:14... Started behind the 4:00 pacer and felt really good. Had a small bottle of water with me (as Brighton give out cups and didn't want to stop!!)... Did the first half in 1:56 so a tad fast, decided to drop the pace as it was hot (I had been training in winter in Scotland lol).  At mile 15 I started to really suffer (came on very fast) and even slowing down was not enough, I had to stop and walk (never did this before)... As I saw my time move away from the 4 Hr, I tried to pick up again but couldn't... This happened the whole way to the end, mixing running with walking. I slowly saw my 4:14 time go and then I was determined not to go beyond 4:30, and completed in 4:25.

The route has a lot of switchbacks which really affected me mentally, seeing these runners pass by me that I was running with not too long before!!! 

When I got to the finish I got really dizzy and cramped up... I drank my electrolyte drink but got sick on the bus to the car-park (fluid)...

I reckon I didn't drink enough in the first half and during the second half I stopped at every water station but by then it was too late!!!!

I will learn from this and either carry a camelbak for the next or take the water as it comes.

Thanks for listening and be careful out there



wbo - on 10:04 Wed
In reply to Euge:. You're absolutely sure it was dehydration rather than just blowing up, though they can be hard to separate.  Heat can be difficult to manage too.

My thoughts - what are you wearing  - the fashion nowadays seems to be too much.

I wouldn't wear a camelback - I would however say to myself ok I need to drink properly, and if that means walking for 10seconds every 5km that's ok (to use a cup)

Trained ok, tapered properly, no overtraining or fatigue?

Wanderer100 - on 11:09 Wed
In reply to Euge:

Did you eat anything whilst running or take on any energy drink or energy gels? Sounds like your blood sugars crashed. How far did you run in training and did you do many runs longer than 15 miles? I always take on food and water wherever possible. Paper cups aren't ideal but I understand they are better for the environment than plastic bottles but taking in plenty of water is important for me and even if half of it ends up down my front then at least than the other half will be going down my neck.

Euge - on 11:16 Wed
In reply to wbo:

I think my clothing was ok... 

I wore a camelbak during my long runs in training and it was the business...

Training was great as was my tapering... I felt great and strong.

My only concern, and still is, is that if the long runs are not at my target pace... how can you switch it on for 26miles??



Euge - on 11:24 Wed
In reply to Wanderer100:


Took gels every 5 miles as in training...

In training ran up to 22 miles including 18miles and 2 x 15 miles... In fact 10 Half marathons

Thanks for feedback


Eric9Points - on 11:38 Wed
In reply to Euge:

Did you take any gels during the marathon?

Wanderer100 - on 11:56 Wed
In reply to Euge:

You were certainly prepared for the distance then and you weren't short of energy foods. It's a hard one to answer. I ran a marathon last autumn and felt fine apart from the last 5 km and didn't do anywhere near the training you did.

Did you run much faster on race day compared to your training runs? Maybe you overdid the pace. I stick to 5 minute kms when long distance training but closer to 4.30 for 10kms and 4.00 for 5kms. 

wbo - on 11:59 Wed
In reply to Euge:well if you were doing all your long runs at target pace then every long run would be very hard.... So you'd need to have done some kind of faster work.  Then you let your training, taper, adrenaline get your pacing up.

How fast we your fastest 1/2? Do anyshorter races?

Phil79 - on 12:24 Wed
In reply to Euge:

Quite tricky to pin these things down in my experience.

Sounds like your training was spot on. Might have been simple dehydration if you didn't drink much in first half?

Alternatively, could be lack of electrolytes if it was hotter than you expected, and you sweated a lot?

I ran London last year with a 4 hr target time. It was freakishly hot for the time of year. Mid to high 20s on the tarmac, following weeks of cold weather, hottest LM on record, and I suffered as a result.

First half I was bang on 2 hrs, then really fell apart in the second half, cramps from about 16 miles, and lots of walking. I drank loads of water due to the heat (lots more than I usually do) and I think it depleted my electrolyte levels, as I had never experienced cramp before. Probably should have drunk some lucazade or similar, but I didn't want to try anything new on the day so didn't touch the bottles they were giving out (my wife did and she was fine!)

Ended up with a time of 4:27 and felt really awful afterwards, which continued for about 24hrs!

My training runs were up to 21 miles at target pace which went fine, and my eating strategy was the same as in training. So I can only put it down to heat and dehydration on the day. 

Incidentally my wife also ran Brighton on Sunday, she said it was fairly cold & windy (but then we live in Devon not Scotland!). She came in at 4:30, so you may well have crossed paths.

Better luck next time, I think its really hard to bring it all together on the day!

Post edited at 12:37
Euge - on 13:05 Wed
In reply to Phil79:

Thanks for that...

My friends that live in Brighton thought it was cool as well,, but they were spectating on the seafront which was windy... also I have been training in winter in Scotland lol...

However, I saw a few people collapsed on the route and a lot of reports of sunstroke!!!

Question, did you train your long runs at race pace?



Euge - on 13:07 Wed
In reply to wbo:

My PB's are 

5K: 23:17

10K: 49:30

Half: 1:54:43

Full: 4:14:44

r0b on 13:32 Wed
In reply to Euge:

A weather station in Brighton reports that the temperature on Sunday was less than 10C pretty much all day, I don't think this is anywhere near hot enough for dehydration to be a problem


The most likely explanation is simply that you ran the first half too fast, which - if your HM PB of 1:54 is recent - is almost certainly the case if you went through halfway in 1:56

Phil79 - on 14:00 Wed
In reply to Euge:

> Question, did you train your long runs at race pace?

Most of them yes. Certainly the longest one (21 miles) I did at pace (9 min/miles). 

That made it even more annoying when my pace went tits up from mile 16 onwards! 

Roadrunner6 - on 14:04 Wed
In reply to Euge:

It really doesn't help. You are carry weight, that slows you down. You don't drink and breath efficiently when you are sucking up liquid. 

Your long runs shouldn't be at target pace but the end should be.

1 x 22 miles, 1 x 18 and 2 x 15 miles is not enough.

For Boston I did 1 x 26, 1 x 24, 1 x 21, 2 x 20, 1 x 18 and god knows how many 15-16's and mid week 10-13 milers. 2 long runs over 16 miles will give you very little adaptation.

Michael Hood - on 14:07 Wed
In reply to Euge:

So aiming for 4 hours you went through half in 1:56.

Ideal is neg split so let's say ideal first half would be 2:01.

That's 5 mins too fast which works out at 23 secs/mile too fast. That's quite a bit.

So although you may have been dehydrated, etc, sounds like you've basically blown up, or at least all the factors together have caused you to blow up.

Trying to get it back again. From there - no chance.

Bit surprised that the 4 hour pacer did first half in 1:56, but then pacing is a difficult thing to do.

Euge - on 14:11 Wed
In reply to Michael Hood:

I thought he was going too fast, that's why I backed off.

Also demoralising seeing your pacer get further and further ahead lol !!!

Roadrunner6 - on 14:39 Wed
In reply to Euge:

Poor by the pacer, a few seconds per mile as the course changes is one thing but not that uneven. He shouldn't be trying to bank time. 

I have seen people brag "Brought the sub 4 group home in 3:50".. as though it was a good thing.

I paced the women's Olympic trial qualifiers at Philly and we ran 6:15 pace or whatever it was almost regardless, even into the wind, down the hills, bloody hard work. 

Euge - on 14:46 Wed
In reply to Roadrunner6:

I spoke to the pacer beforehand regarding his strategy, as I was not interested in banking time.

He did say it would be a consistent 9min/mile!!!

Still, not blaming him... it is my race after-all


Roadrunner6 - on 15:10 Wed
In reply to Euge:

That's 4 minutes under 4:00 isn't it?

That's a very odd attitude but I can't say I'm surprised having heard others. 

Roadrunner6 - on 18:55 Thu
In reply to Euge:

I was thinking about this last night as I am trying to analyze boston.

Sadly its all academic and futile. There's so much that can go wrong.

I slowed and ran 1:23:30 1:26:25 halfs. Did I go off too fast? Humidity? It is a slower second half but my legs didn't come back for the final descent. 

Not enough conditioning from specific down hill running, just not enough miles in general.

Diet the day off, food in the race, different gels. 

Did my low grade cold I have play a part..

It could be anything, its the beauty of marathons.

I saw one old elite runner call everyone 'onfa'z'

The old "I was on for x before y" excuse we all trot out. I don't know anyone who reckons they actually ran the best marathon possible at the peak of fitness. Me being a classic example, I was 2:36 but was "on for" 2:30 once at Berlin before a back issue meant I had to DNS.

Post edited at 18:56
Dom Brown on 11:33 Fri
In reply to Euge:

I also ran brighton. my pace died off from about 21 miles. 

It started out much warmer than expected, and the head wind when running east (about half the time) was brutal.

The race winner had said that the wind was the worst he'd known. so you might just have been unlucky.

Roadrunner6 - on 17:21 Fri
In reply to Dom Brown:

I read Russel Runners blog and he said similar. He ended up in a disappointing 2:28..


DancingOnRock - on 22:44 Fri
In reply to Euge:

If you drank at every station after halfway you could have been over hydrated or suffering from hyponatremia. That will leave you feeling confused, and sick.

Brighton is my PB. Favourite bit was out to the Marina, also enjoyed the bit out towards Hove, unlike some, but messed up my calculations and was behind target pace so reduced pace at 40k in order to have less pain!

mountainbagger - on 08:05 Sat
In reply to Euge:

I've run Brighton multiple times. I've blown up around mile 15 a couple of those times from going too fast in the first half. There's more ascent and descent in the first half so it's harder. So, I agree with the poster who said 1:56 seems quite fast, given your PBs and target time.

I personally always feel sick after long runs when working hard. I'm still working it out, but suspect dehydration is main cause. Salt tablets and Tailwind have both improved things, whereas gels always seem to make me feel queasy.

Better luck next time chasing the PB!


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