Powering your distance run: Dupl expert Alex Cook helps unlock a new personal best for marathon runner

Powering your distance run: Dupl expert Alex Cook helps unlock a new personal best for marathon runner

If there’s one thing that every runner knows, it’s that your body will tell you when something isn’t right. If the problem recurs, we might consult other runners, personal trainers, search engines or our GP to find a solution and move past it. But we’re all unique – what works for the runner in front might not work for us. So where do you turn if you come up against a roadblock you can’t beat, despite having tried everything to resolve it?

Meet Martin. By day, he’s a National Sales Manager for Horseware Ireland. Outside of his challenging job, he’s a 44 year old distance runner who takes his passion seriously. It in turn takes him to marathons across the country. The goal powering each race? A sub three hour finishing time.

But Martin found himself frustrated by a struggle to beat his target times in training and demoralised by the violent sickness that would follow long runs. Feeling far from his sub 3 goal and with his very passion for running in doubt, Martin came to Alex having hit a wall he didn’t think he could break through.

I had to take a pop-up tent with me to give me somewhere to lay down as soon as I finished a marathon – I just wasn’t capable of anything other than being horizontal and throwing up for hours after a race. I’d become so concerned about the problems I was experiencing after running that I was considering giving up running completely.

So with Martin’s motivation depleted and severe sickness threatening to end his distance running for good, how did 1:1 support from Alex help him?

So Alex, you’re a dietitian specialising in endurance sports nutrition and a competing distance runner yourself. You must have empathised with Martin’s situation – where did you start?

It was no wonder that he was considering throwing in the towel on his passion! But I was confident that identifying the root problem and creating a personalised plan could help him overcome his issues and even exceed his goals. We went right back to basics with an analysis of his whole diet and lifestyle. It was important to understand how he was fuelling his life, not just his training. It quickly became clear that despite taking on fluids before and after exercise with minimal during,  Martin’s post-run illness was down to severe dehydration.

Dehydration? How did that cause such a severe response?

Well, prolonged exercise exposes athletes to the risk of dehydration because you’re sweating for long periods of time – you’re perpetually losing water while your body tries to cool down. And yes, the problems it causes can be dramatic. Even being dehydrated by 2% of bodyweight can result in stomach upsets, loss of coordination, increased heart rate and having to work much harder to keep going. The worse the dehydration, the more pronounced the effects. In Martin’s case, he was susceptible to losing fluid fast, so it was a question of altering his fluid intake across his whole diet to keep him properly hydrated for a run.

So how can dehydration be avoided?

As with most things body related, there is no one-size-fits-all solution. The only general rule is that you need to drink sufficient fluid to match your sweat loss. It’s simple to calculate your personal sweat rate by measuring your mass before and after exercise but Martin benefited from help to understand all the factors affecting it. For him, and many others, it isn’t simply a case of ‘drink more’. Nutritional intake, environment, length and intensity of exercise, metabolic rate and even genetics can all have an influence, so developing a new hydration plan that was tailored to him was the difference between giving up the sport he loved and harnessing his potential to improve his running performance. Six months sticking to a personalised nutrition and hydration plan that worked in harmony with Martin’s lifestyle and training helped him to fall back in love with distance running. And of course, it wasn’t long before his personal best followed.

I can remember the first run that I hydrated myself in line with Alex’s guidance. It was like switching on an ability to cover distance at pace. Not only did I not feel desperately ill after the run, I carved chunks off my usual times. The final pay-off came at the London marathon this year when I bagged a time of 2:56. And I didn’t need my tent!

So understanding your individual needs is key. Any tips to get people started with better hydration?

Sure, here’s a few things that will benefit everyone.

  • Start the race hydrated, having little and often during the morning (300-600ml)
  • Try and match fluid intake with weight loss (but don’t overdo it and drink too much)
  • During the marathon, drink early and taking ‘little and often’ is better than large doses
  • Do not over drink, weight gain during a marathon shows an increased risk for hyponatremia (when the sodium in your blood drops abnormally low)
  • Sports drinks or water are the best options
  • If it is hotter than you are used to on race day, be prepared to slow your pace, as drinking more fluid won’t necessarily cool you down
  • After the race you need to drink 150 per cent of fluid lost (if 1kg weight is lost, you need to drink 1.5 litres) over the next one to two hours and then little and often through the remainder of the day.

Want to find out what 1:1 nutrition and fitness advice can do to help you?

Try Dupl for free with a 1 week trial


Alex Cook, Dupl expert in performance nutrition,  is a qualified Dietitian, Sports Science graduate and competitive runner and loves all things running and nutrition!  She recently started running ultra-marathons, and earlier this year won the Endurance Life Exmoor Marathon, beating the course record by 14 minutes!