The Ridiculous Swim – Eton 10K Open Water Swim Race Report

At some point swimming ten kilometres seemed a good idea. Sufficiently good for me to enter yesterday’s Eton 10K Open Water Swim. I hoped fear would be enough motivation to get me back in the pool. I wasn’t afraid; as an unusual birthday celebration I’d swum seven kilometres in the Tri2O Lake two year’s ago, I could manage three more. Boredom was a bigger concern, if anything would motivate me to train it was the thought of finishing earlier. My distinct lack of enthusiasm remained till race day.

I didn’t need an alarm on race morning – a painful calf cramp woke me before my watch went off. An inauspicious start, I’d memories of Ironman UK where I cramped in the swim, at least I wouldn’t have to bike after this. Cramps are rare and not a good sign; it might be an electrolyte issue, but more often it’s a strong indicator of heavy fatigue. Since returning from Lanza I’d not been one hundred percent. I hadn’t raced, but my body was trashed – perceived exertion was high while heart rate was low, I was retaining water and felt lethargic.

No excuses, I wasn’t backing down. I found some High5 Zero electrolyte tablets in my box of sports nutrition and downed them hoping they would alleviate further problems. Otherwise a regular breakfast, plenty of coffee and a final check of the race bag. I prepared my pre-race nutrition as recommended by Gordo Byrn600 calories in fluid form – three sachets of High5 2:1 Energy drink concentrated in a bottle. I was winging it: no race plan and I’d only considered fuelling the previous evening. I’d not even tried the High5 drink before. I put thoughts about stomach issues to the back of my mind, doesn’t fructose disagree with some people?

Speedo Open Water Swim Series Eton 10K - Dorney Lake

For once it didn’t matter that the weather was miserable, I’d be wet anyway and when I left the water the race was done. Sheltering under bushes I pulled on my race wetsuit and liberally applied vaseline to the neckline, three hours of chaffing was a painful prospect. With twenty minutes I put Gordo’s advice into practice – I downed the energy drink. It was hard going, I felt bloated and understood why it stopping him going out hard. In theory I’d consumed the fluids and fuel to swim 10K without a stop.

Despite contrary advice to Ironman athletes I was unwilling to place myself too far forward on the start line. This was a long training session and surely only strong swimmers would enter a 10K. When the horn went I hit upon a familiar problem: lots of slower athletes ahead. I’d anticipated a civilised swimmer’s start, but there was all the rough of a typical triathlon. Passing people more frequently than expected, but certain I wasn’t pushing the pace; everything was focussed on a comfortable stroke I could maintain for the next few hours.

My lack of racing showed, I was uncomfortable surrounded by others and with the constant contact that entailed. Part nerves, part frustration, I wanted clear water. The first lap never offered it, with swimmers around me I made frustrating progress. Using an old pair of goggles wasn’t helping; comfortable, but worn, my visibility was limited to a few meters. I’d only a vague idea where I was in the lake and who was nearby. Zig-zagging between swimmers I rarely held a straight line throughout the first five kilometres.

Cramp hit my right calf about a kilometre down the opening straight. I was calm, relaxing the leg and letting it slowly release. It passed as quickly as it arrived. The second came in my left calf no more than five hundred metres on. For two laps a pattern of alternating calf cramps plagued me. Each time: stay calm, relax the leg and let it pass. I cautiously scrunched my toes and flexed my legs hoping it would delay further onset. By the last lap they’d vanished, I suspected my legs were too tired to cramp anymore.

Two loops of crowds, meanderings and cramps; I entered the final lap feeling strong and with the clear water I wanted. Race nutrition was working – I’d not had to stop and still had more in me. I found the buoy line, a rope ran along the bottom that eliminated sighting issues, I picked up the pace. Technique and timing clicked; it felt good – I was working well. This far into the race I couldn’t say whether it translated to speed or holding on to what I had. Relative to the field I was moving, I passed swimmers picking a few up on my feet as I went.

Everything went into the closing four hundred metres. Once again my goggles let me down as I arced wide into the finish line. I wasn’t fast out of the water – nervous of cramping when I stood, I paused before steadily jogging to the timing mat. Job done.

For all my doubts I thoroughly enjoyed the race. I regret not prioritising it more, but lessons have been learnt. I can pace better, put more in early on and stay focussed; I can wear better goggles and actually see where I’m going; I can practice my drafting and relax more in contact with other. Next time – there will be a next time – I can actually race and perhaps improve on my time of 3:00:31.

The hunt is on for more long open water swims (that allow wetsuits). Swimming long is fun.


  • Mark

    Hi Russ, Have you thought about the Henley to Marlow swim organised by the guys that do the Henley swim? It’s about 14k, downstream and is more in line with a cyclosportive than a race.

  • Hi Mark,

    Unfortunately I’m away that weekend, otherwise I’d have my entry in already! Looks like a great event.

    Wetsuit allowed, long open water swim events seem to be rare.


  • Susie Phillips

    Well done Russell. Enjoyed the report.

  • Peter Cusick

    I did a 750m OW swim once with goggles like that – absolute nightmare………10k……………..extremely well done.

  • James

    Well done, Russ. This will be a def for me next year.

  • Thanks for the comments.

    I surprised myself with how much I enjoyed the event. Time passed so much quicker than expected; I’d thought it would be boring! DEfinitely looking to do more in the future – though not hard core enough to consider non-wetsuit.

    James – thoroughly recommend it. Great fun and a real sense of achievement. Only warning – it’ll change your perception of a long swim. I can’t be bothered entering a 2.8K or 5K swim, seems too short!


  • Jane Mitchell

    Really enjoyed reading this Russ. It was the 10k swim at Beijing that re-alighted my passion for long distance swimming. The farthest I have done in a race was 3.6 k last year but I hope to do a 10k soon. Well done

  • good read buddy :o) iam booked in for a 10km in september but iam training just for the event ! time wise i need to work out but love to hit around 2:10-2:20 …… TIME WILL TELL

  • Mac

    I’m signed up for Windsor in September and I’m terrified. I’ve done a 5km but never anything near 10km. Pool time is difficult to get, so a long 8km swim isn’t possible in the time the pool is available. Any tips would be very welcome. I was hoping to do it around 2 40. So fingers crossed.

  • Mac,

    I wouldn’t be terrified, I got round on surprisingly little training, though at a far more modest pace than you’re intending. Any open water options for getting a couple of longer swims in? I’d not stress too much about really long swims prior to the event, rather if you can get a good routine and consistency of swimming going with perhaps a couple of long sessions around the 6K mark in there you’ll be fine. I’d look to swim as much as you can during the week, mix of sessions, obviously plenty of longer sets, but still keep some shorter/faster sets too; and I’d look to try to get 2 long sessions in at an open water venue, swimming for a couple of hours each time. If you can swim for 2 hours continually, you’ll be fine for 2:40.

    Is that the Maxifuel Big South Swim Challenge at Bray Lake that you’re doing? If so I’ll be there supporting. Had considered doing it myself, but having decided to focus my efforts on running for a while didn’t fancy another 10K swim without some preparation.


  • Mac

    Thanks for the advice. It’s good to have some things to focus on as I’ve been heading towards the swim without a clue. I’ll try getting some ow swims in before and will definitely do some longer swims in the pool too. I’m quite happy to do a 6000m set so that isn’t a problem. Yes, it’s the swim down in Bray Lake. It is bound to be warmer than up here in Scotland so I’m looking forward to that at least!

  • Andy firth

    I am planning to do this10k swim next year, very nervous about it.
    You mention a rope running along the bottom, is that visible as sighting is my biggest concern ?

    What are the best per swim eloctrolyte products you would recommend .


  • Hi Andy,

    Assuming the set up is the same as when I did it and it’s swum in the side lake, then the ropes should be visible. They are quite deep though, so I wouldn’t guarantee this as water clarity might be a factor too. Once I’d found them though I was able to largely follow them without any issues. You will probably find the start of the race is too hectic to easily get to that line, unless you place yourself well back or are swimming off the front, but as it settles down you’ll be fine and initially you can just follow others. Sighting in general isn’t too much of a problem because you’re going up and down a straight man-made lake, you can see the banks to help guide you too. As well as building up the distance you can swim and working on your endurance practice sighting, you can do it in the pool too, mix it in with the occasional set.

    Regarding electrolytes – they are all much of a muchness really. I’ve used Nuun and High5 products without problem, they taste nice and dissolve easily. Lately I’ve been using MyProtein Electrolytes Plus pills simply because they’re cheaper and basically contain similar salts. Any should work and if you take a good dosage before the event may help avoid cramps. Just be aware cramps are caused by many factors, including fatigue so training sufficiently for 10K will help.

    On the training front – once open water season starts next year get yourself into a lake (though it’ll be cold), slowly build up the distance you swim over the couple of months you should have before the event. If you can do a 7K swim at the weekend in training, you’ll know you’ll be fine. In the pool in the meantime over winter, there’s plenty of time to build endurance there too, it doesn’t have to be long sets, frequency of swimming and a few decent sessions will help. I would say, don’t be too nervous, it’s not as tough as it sounds and as long as you’ve got some training in in the few months prior to the race and got comfortable swimming at a steady pace for longer distances you’ll be fine.


  • Andy firth

    Thanks Russ much appreciated.
    I am swimming 3 2 mile pool swims a week at the moment and doing that comfortably. Am going to continue working on my endurance through the winter. Have done my first couple of open water mile swims this year. Plan is to do a lot more next year.
    Definitely going to give it a go. Cheers for the great advice.

  • Hi Guys,
    Get yourselves up to the Lake District with a few mates, buy a flag alpha and hire a rowing boat for safety cover and then try swimming Coniston (8.7km), Ullswater (11.8km) or Windermere (16.8km). I’ve done Windermere wetsuited and it was a fantastic experience – the spectacular scenery beats multiple laps around a man made muddy pond any day!