Week 3 of my Marathon Tips and Experiences from taking part in the Marathon des Sables, billed as the ‘toughest footrace in the world’.
Hydration: “Water is the driver of Nature” — Leonardo da Vinci
Water is: 70% of muscle; 80% of blood; 85% of the brain.
Every physiological and biochemical process in the body takes place in water. Water is so vital to our bodies that we even have an organ dedicated to reclaiming some of the water that would otherwise be excreted with waste — the colon (or large intestine). So, we know that water is essential but how much should we drink and in what form.
Pure, filtered water is preferable as tap water has a cocktail of chemicals to ensure it is safe to drink (in the UK). Some naturopaths advocate drinking between 2–3 litres/day and more if exercising or sweating. Whilst this might seem quite a lot, I would aim for around 2l/day. If you are not drinking anything like that amount, I suggest you slowly build up to that, rather than try and achieve that over a short period of time as the body needs to get used to being properly hydrated, slowly.
One thing’s for sure: if you only drink when you’re thirsty, your body is already dehydrated. Get used to drinking at regular intervals — preferably not at the same time as eating (as this will dilute your digestive juices and render digestion less effective). Between meals is best. An easy way of determining if you’re dehydrated is to check the colour of your urine when you go to the bathroom. The lighter your urine, the more hydrated you are (nb. If taking vit B supplements, this will colour your urine yellow, rendering this simple test useless).
Don’t be tempted to drink carbonated drinks (including sparkling water). The carbonation will alter the pH (acidity/alkalinity) of your blood and strip your bones of calcium.
Use sports drinks during your training runs and the marathon as these will replace not only the lost fluids through sweating and breathing, but will also replenish the electrolytes lost through sweat and provide much needed carbohydrates to maintain your energy levels. During the race be careful to maintain your usual routine of replenishing fluids at regular intervals; it can be easy to get distracted by the occasion and hype of the event and forget the basics.
During the Marathon des Sables, we were given 2l bottles of water at dedicated pit stops along the course each day. Once we had used our quota for that day, that was it; it was used for everything — drinking, washing, brushing teeth… it was a balancing act. I carried a bottle of concentrated electrolyte fluid for the week and added it to the water bottles. Getting the correct dilution was crucial. I knew of at least one competitor who got his ratios mixed up and quickly became dehydrated — the Sahara is not the place to get this wrong. He struggled on, unaware of his mistake. He was one of the front runners that year — young and very fit. Forging on, he began to ascend up a very large sand dune. With fewer than 200 competitors strewn over the vast expanse of the desert course that year, it was easy to lose sight of fellow competitors very quickly. Under the relentless desert heat, and with the effort of climbing a steep sand dune, all the while losing water through sweat and the sheer effort of breathing in the airless desert furnace, the competitor fell onto the sand, exhausted.
Because there were so few runners taking part compared to nowadays, no one passed by close enough to stumble across him. The first the organisers knew of any problems was when runners failed to register their arrival at the end of that day’s course. All they could do was retrace the course for that day — but with the longest day being 50km, over rough terrain and sand dunes, their jeeps could only manage the stony desert floor — some sand dunes were too steep for vehicles.
The competitor was blessed — some local Berber’s in a passing camel train passed close by and spotted the collapsed man in the sand dunes. They hauled in on a camel and delivered him to the safety of the camp. It was his lucky day. Others were lost in the desert as night fell, and the Sahara, shrouded in blackness was impossible to search. Although all competitors carried flares, time and distance was impossible to gauge in such a featureless landscape.
Next week: Stretch, Stretch, Stretch