Much has been written about fuelling and hydrating for marathons (or eating and drinking as normal humans refer to it) and the advice is often conflicting.
The legendary British runner Ron Hill ran his debut marathon at Liverpool in 1961 and recounts the rules forbid drinking at all until 10 miles irrespective of conditions, and then drinks only at 15, 20 and 25 miles. When questioned on what he ate during a marathon he’s previously responded that it isn’t a picnic it’s a race. To anyone that has run London Marathon and the like and seen aid stations every mile with water, gels, fruit and sweets this sounds inconceivable. It should be noted Ron has a marathon PB of 2:09:28, winning Commonwealth Gold and is still one of the fastest marathon times by a Briton.
Over time the advice on hydration during races has swung from one extreme to another and no one demonstrates this better than Dr Tim Noakes. An accomplished Doctor of Medicine and Doctor of Science with degrees from the University of Cape Town in South Africa, he has raced at a very competitive level in more than 70 marathon and ultramarathon events.
Dr Noakes recalls that for his debut marathon in 1972 there was a single aid station at mile 20 and runners were actively warned not to drink during exercise. This seemed at odds to various articles and publications at the time advising that being denied hydration could eventually lead to deaths. Dr Noakes took up the mantel for the cause and penned various articles, some as prescriptive as recommending 900ml per hour. In a further article in 1981 he recommended marathon competitors should drink whenever possible and as much as able. The guidance continued in this vain and The American College of Sports Medicine in 1996 advised drinking over a litre per hour or “as much as tolerable”. In public perception if you were thirsty in a race it was already too late. This potentially lead to deaths from exercise-associated hyponatremia (a low sodium concentration in the blood).
The symptoms of hyponatremia are confusion and loss of consciousness and often appear similar to dehydration. It will probably never be known how many runners collapsed during events and ultimately died or had the condition worsened as a result of well-meaning spectators and medical staff forcing more water upon them. Due to a quirk in the brain much as patients with hypothermia can feel they are burning up and seek to shed more layers (paradoxical undressing), those suffering from hyponatremia can shut down urine production, exacerbating the fluid retention. Continue to drink and your body and tissues become bloated. With only a minimal loss of fluid through sweat the brain can swell, pressing on the blood supply to it and in serious cases causing brain damage, loss of breathing and death. All from drinking too much water.
Dr Noakes and others continued to research in this area after learning of deaths and revised his beliefs as did the general medical guidance. In 2007 the American College of Sports Medicine published new guidance and Dr Noakes released “Waterlogged: The Serious Problem of Overhydration in Endurance Sports” in 2012. The basis of both is that you should drink to thirst. As with many things in running the message is ‘keep it simple’.
The main takeaways from Dr Noakes book are that overheating and dehydration are not linked. Run too fast and you overheat regardless of hydration. Your body will control this overheating and force you to slow. Heatstroke is very remote without another underlying ailment or medical issue. Some dehydration is to be expected during exercise and again the body controls itself and signals thirst as required. Access to water is key but drinking prescribed volumes at given intervals, or drinking early to get ahead of your thirst is strongly advised against. At best it will be detrimental to your performance, at worst detrimental to your wish to continue to exist.
So where is this all going?
Influencers. Don’t they annoy you? You can barely click on twitter or Instagram without some bright-eyed runner with overly-filtered selfies extolling the virtues of their pre-race routine that for a mere £49 a month they’ll share with you. It will require you to wake many hours before your race and waste precious beauty sleep on pointless rituals. Most will recommend overnight oats and often use the same stock images of beautiful oats in a gleaming mason jar, topped with a luscious compote of goodness. Why the same stock images? Because most of the time it looks like sick in a glass with a leaky highlighter mashed in top. Have some toast and get over yourself. If you’re thirsty have a drink, don’t chug 2 litres the minute you awake, a further 2 litres on the start line and then a bottle every mile.
The nutrition during the race is no better. If it’s not a ghastly powder with dubious unproven medical claims it’ll be a bar made up of floor sweepings from the local hamster food factory bound with honey and costs multiple times more than a far tastier Mars bar.
On the flip side are the hard-as-nuts influencers that label every run with ‘fasted’ to show how awesome they are for attempting the unimaginable feat of running around their local playing field without a pre-exercise jar of vomit. I don’t run fasted, I just can’t be arsed to make breakfast most days.
You’re still not getting to the point are you?
Nearly. I’ve run a lot of marathons. I’ve experimented with kit, food, drinks and pace but I’ve always been curious how much difference it all really made. Whilst in Spain on holiday I ran most mornings straight from bed to run in as few minutes and metres as possible because I had a busy day of drinking beer and eating tapas ahead of me. I hadn’t consciously avoided taking water on these runs but hadn’t felt I needed it. After a week of acclimatising I decided to try an experiment and run marathon distance at my usual pace, with no food or water and see how I fared.
Background
I was going through a decent patch in my running. Most of the year I’d been running broadly 80/20 effort approach, so much of my miles were very easy with hard efforts reserved for races or key sessions. After concentrating on the Transgrancanaria ultra in February, I returned focus to shorter stuff and in March ran a 3h28 marathon in a gale, and a 3h32 a few days later as a part of a race series. At the end of the month I managed a relaxed 3h22m followed by pacing the MK Marathon in early May at 3h45m. Late May and just before we left for holiday I squeezed in a looped trail marathon as a test of fitness and achieved a 3h14m, only a few seconds off my PB and slightly hampered by the punched card lap arrangement. It was arguably my best marathon performance ever, and run mostly to feel and a steady pace.
The Test
My goal was to run ‘fasted’ with nothing pre-run or during until I absolutely needed it. If I felt good I would run to marathon distance. If I started to feel awful I’d call it quits and end earlier. The route was along the beach between Cambrils and Salou so there were shops, showers and water fountains at regular intervals. I wasn’t running across the dessert unsupported for a laugh and likely death. Target was to hold just under 8 minute miles for the duration of a 3h30 marathon. I set off in the morning, straight from bed to beach in a few minutes without food or drink prior to starting. The temperature was around 20degC so warm but not excessive to start with.
With podcasts to listen to the miles went quickly and half marathon passed easily. I was running mostly to feel but checking pace at intervals to avoid going too fast. After 14 miles the effort level needed to maintain the pace increased a little but was manageable. I was also starting to feel thirsty. The dripping from my cap reminded me I was sweating at a fair but manageable rate.
18 miles is often referred to as ‘the wall’ in marathons and was the last mile I managed to keep sub 8 for. Was my body slowing or my mind using this measure as a good excuse to slow? The thirst was building and I was also getting hot with the rising temps and increasing effort level so diverted via a few of the beach showers to cool myself down. This slowed the decline and I was on the way back to the villa now.
Mile 24 required climbing the hill back up to home and saw a 9m53 mile as I lacked the ability to push the hill. By this point my thirst was definitely strong but I still had no desire to eat. Hovering around 84kg I’m a long way off wasting away so have fat reserves for days. Back at the villa I ran through the kitchen like an aid station and downed a half litre of the local generic sports drink (a knock off version of Aquarius with sodium) before heading back out to round up. Hot and bothered I was where I expected to be but not enjoying these last few miles. The pit stop caused an 11 minute mile which didn’t help the average.
The drink appeared to hit the spot, although how much is placebo is impossible to measure. The final mile and a bit was at a restored 8m28 pace and I finished the marathon in 3h36 and an 8m15s average pace. One marathon done in comparative warmth for a Brit (was approx. 30degC at the end).
The Outcome
Depends on your social media view. It’s either:
“Man runs marathon distance, gets a bit thirsty, has a drink, finishes it marginally slower than his usual times.”
OR
“Runner RISKS LIFE, attempts unimaginable distance in FASTED state, eschews VITAL gels and fluids. What he does at mile 24 to CHEAT DEATH will shock you.”
Either way I’ve found I can skip breakfast and happily run at (for me) a decent pace for 18 miles before struggling, but just need a drink to pep myself up. If nothing else it will build confidence if I miss a drink station on a PB attempt that I won’t expire instantly and can just get one at the next table.
Next time you’re at your 15th water station of a marathon, perusing the brightly covered offerings, consider maybe what you need might actually be nothing at all if you’re not thirsty.