No-nonsense hydration
How to manage your hydration and electrolyte levels to run better
Hydration is crucial to running success, but it’s something a lot of people neglect. Just a 2% loss in body weight due to dehydration can impair performance, so fluid intake during exercise is essential, especially during longer sessions and competition events. It helps to maintain hydration, body temperature and adequate plasma (blood) volume.
Ensuring your plasma volume and temperature stay optimal has a direct impact on performance. When plasma volume decreases, it leads to an increased heart rate, which in turn accelerates fatigue. Dehydration also affects cognitive function, resulting in an inability to think clearly. Symptoms of low sodium intake and dehydration include gastrointestinal distress, nausea, bloating, fatigue, impaired concentration and dizziness.
The importance of sodium Sweat consists of water, minerals (sodium is the key component), lactate and urea. Sweating is crucial to thermoregulation and is therefore necessary during times of physical exertion or exposure to hot climates.
Most runners sweat between 400ml and 2,400ml per hour of exercise, with the average value being around 1,200ml per hour, although this will vary with age, sex, weight, intensity and the outside temperature.
The sodium content of sweat varies substantially, from 115mg to greater than 2,000mg per 100ml. But a runner who’s a ‘salty sweater’ (ie, has a high amount of sodium in their sweat) may lose more than the recommended intakes. I often suggest that runners take 700mg to 900mg of sodium per 1,000ml of fluid during longer training and competition. This can be a mix of salt tablets, energy drinks, whole foods and electrolytes.
What are electrolytes? Electrolytes are essential minerals (including sodium) that the body needs to stay hydrated. However, they also support important processes in the body such as muscle contraction (including the heart), blood pressure and nerve signalling. Electrolytes help your body retain fluid during exercise when you are sweating, as they draw fluid into working muscles.
Electrolytes come in many forms (powders, tablets, sticks) and are often added to sports drinks. Most provide 250mg to 300mg of sodium per serving. But some sports nutrition brands, such as Tailwind, Veloforte and Active Root, have realised the importance of salt, especially in long-distance events, and have created products with a higher sodium content. I like chewable forms of electrolytes – SaltStick Fastchews are my choice, as I find it easier to know how much sodium I’m consuming. It’s also possible to use real food in ultra-distance races. Some ideas include salted peanuts, mashed potato with cheese or Marmite, cheese straws and jerky.
Sodium balance and hydration is not just for while you’re running – it’s equally important leading up to an event. I recommend that individuals start drinking electrolytes in the 24 hours prior to race day. Precision Hydration has a variety of products for this.
Replacing electrolytes postrun or race is also key. One of the best options is cow’s milk, as it not only replaces fluid, but also has carbohydrate and protein in the right ratio to encourage recovery, while being rich in electrolytes.