Ed: Dionne has written a piece about dehydration that spells out the dangers and importance of preparation. If you have any comments please leave them for us and if you’d like to contribute, please contact me.
The ballot for the London marathon 2012 has been drawn and autumn marathon season is well and truly underway with less than a week till marathoners take a bite of the Big Apple across the other side of the pond…. forget Christmas, marathon fever is upon us!!
This casts my mind back to this year’s London marathon; there I was at the mile 25 mark watching zombie like figures stagger along the Mall. It was obvious to me that many of the runners had ‘hit the wall’ putting every last ounce of blood, sweat and tears to reach the finish line after 26.2 miles of the famous roads of London town and battling through the pain pushing themselves to exhaustion!
Hitting the wall
This got me thinking; what causes this phase of hitting the wall and how can athletes steer passed it so they have a much smoother and enjoyable ride to the finish line?
It was when doing my dissertation whilst studying sports management at the University of Birmingham that I got some ‘fuel for thought’ about one of the detrimental causes which could have such a negative effect on performance.
Research into dehydration
According to research, one of the common causes of hitting the wall is dehydration. When an athlete becomes dehydrated fluid is lost from the blood making it thicker and harder for the heart to pump an adequate supply of blood with each heart beat. This places the body under huge stress as the heart works to supply an efficient amount of oxygenated blood to the working muscles. Just a 2% reduction in body fluid can have a negative consequence for performance whilst dehydration can lead to a 6% reduction in performance and often will have a detrimental effect on the health of the runner, leading to symptoms such as intense thirst, impaired judgement, fatigue, anxiety, headache and in more severe cases, where adequate fluid had not been replaced, it has been known for runners to suffer from strokes or in extreme cases can lead to death.
Many of us are guilty of waiting for the thirst mechanism to tell us when we need to drink, however there is reason to suggest that this thirst mechanism is ineffective, because by the time it kicks in you are already likely to be mildly dehydrated by around 2% body weight. This is the 2% body weight that can lead to a 6% reduction in performance, meaning those that are not keeping hydrated could lose out on reaching their target time no matter how well their training leading up to the marathon has gone. It has therefore been noted that the athlete must be well educated in the advantages and importance of being properly hydrated in order to avoid severe dehydration and the consequential conspicuous impairment on overall performance, specifically when competing in endurance events like the marathon.
Effects of dehydration
As a result of the notable effects of dehydration on performance, specific hydration guidelines have been recommended by the American College of Sport Medicine. They suggest that an athlete needs to consume between 150ml and 200ml every 15-20 minutes of exercise equivalent. This is up to 600-1200ml per hour. However it is important to note that you don’t over hydrate as this could also cause adverse effects on performance, not least the dreaded ‘stitch’. Fuel for thought indeed!
This brings me to my final thought and the famous quote ‘poor planning leads to poor performance’ as it is clearly evident that without having the efficient amount of fluid in place performance is likely to be reduced and those goals you have worked so hard to achieve will be further out of reach, so grab those water bottles, find the drink that suits you and stand on that start line feeling fully prepared, confident and ready to fly. Good Luck!