In light of the recent humid weather and as many of us begin our preparations for half marathons / marathons in the coming weeks I found this article in Runners World very useful. It is partly an advert for electrolyte tablets but nonetheless one of the most concise and practical articles on hydration I’ve read in a while.
Just 5% dehydration can result in a 30% reduction in performance.
1 Not just water
When you sweat you lose vital salts and minerals. These electrolytes – in the form of sodium, calcium, potassium, magnesium and chloride – are essential for the body to function, regulating blood volume, supporting muscle contractions (hence why cramp can be a problem) and even helping with energy production.
The most important of these is sodium and potassium. Replacing these salts at the same time as taking on fluids, especially when it’s warm, is crucial for effective hydration and avoiding hyponatraemia where sodium levels can fall dangerously low.
Studies by NASA found that sodium solutions were more readily retained by the body and better at beating dehydration. Some of the SE Fitness girls will tell you they swear by dropping electrolyte tables into their water bottle. This is important during the race and also in the days leading up to. Get some now then you can try them out during your training and long runs.
3 The pee test
Checking the could our you pee against the Armstrong Chart is a simple way to keep an eye on hydration levels. You should be aiming for pale straw. Don’t leave hydration to race day! Keep the pee straw coloured in the week before as you don’t want to be guzzling loads on race day itself.
4 Fast Lane Fluids
The rate fluids move from the gut into the bloodstreatm depends on the concentration of hydration solution you sip. With water slower passive hydration tends to occur. Glucose and salts can work together to help speed more water into the blood. Not all sports drinks are the same! Ever wondered at the difference?
Isotonic – classic sports drinks have higher levels of carbs. They are absorbed at roughly the same time as water supplying energy and fluid.
Hypotonic – lower in carbs so you get a more rapid absorption rate than water and best for hydration not energy. Electrolyte tablets in your water fall into this camp.
Hypertonic – have the highest level of carbs so should be used as a supply of energy rather than hydration.
Make sure to mix your electrolyte tables in the right quantities with water.
5 Avoid post-race cramps
For every kg of body weight you lose you need to consume one and a half litres of fluid.
Try to drink 500ml in the first 30 minutes after your run and top up with mouthfuls every 5 to 10 minutes. Add some electrolytes to help avoid cramps.
Hydrate properly on the way towards the beer tent and will help you to recover faster!