Most of us sweat when exercising, it's one of the reasons why gym's are some of the most unhygienic places on earth! Granted, not everybody has the same sweat response, some people can train hard and barely sweat at all, especially in the cooler winter months. Conversely, some only have to look at a dumbbell and they’re sweating like a meathead in a supplement shop!
Sweat needs replacing...
It’s a simple fact that (within reason) what goes out must go back in. Homeostasis (a constant internal and external environment critical to normal health) dictates that electrolyte such as sodium chloride, potassium, magnesium and zinc (for example) must be balanced with total body water. Too much water and we become hypertonic, too little water and you’re hypotonic, either way your body will become imbalanced, and balance is key to survival.
What is sweat?
Sweat is comprised of water, sodium chloride (salt), potassium and magnesium, although the respective amounts vary from person to person. Sweat is a thermoregulatory mechanism that aims to cool you down (through evaporation from skin) and still maintain internal fluid and electrolyte balance.
Going back to why sweat needs replacing, if you consider that many people lose as much as 3 litres of fluid an hour through sweating alone (not including insensible losses such as evaporation through breathing, excretion and so on), then it highlights the need to consume a minimum of 2-3 litres of fluid over the course of the day.
What does YOUR sweat consist of?
The composition of peoples sweat varies, some people lose more salt through sweat than others. A leading sports coach once ran a test to see how much of the electrolyte in his athletes sweat was salt, and all he needed was a black t-shirt. The athletes were told to exercise to the point of sweating, and after were asked to remove their t-shirt and leave to dry naturally. The next day athletes observed their shirts and found some had white patches under the arm pits and lower back…this was of course, salt. Just 50% of t-shirts had white patches which shows that some athletes lose more salt than others during physical activity.
So what should they do?
Let me be clear, just because you don’t have white patches under the arm pits of your t-shirts does not mean to say that you aren’t losing salt, you will be losing it, only some people will lose more than others and may need to up their total sodium intake after and during exercise.
Fortunately companies such as EZ Fuel, High 5 and Science in Sport have formulated some great tasting and optimally balanced isotonic drinks to help you replace all that was lost during exercise, as well as enhancing performance!
Isotonic drinks are pivotal in optimal performance, and several studies support this such as Del Coso et al. (2015), who found that salt supplementation significantly reduced the time it took athletes to complete a half-ironman when compared to placebo. Blood tests also prove that the athletes used the salt rather than simply sweating more of it out, implying that the body actually needed it.
So you can do one of two things, try adding a pinch of salt to approx. 500ml of fluid to replenish sodium losses through exercise, or you can opt for an optimally balanced isotonic supplement that does the job for you.
As a rule of thumb, take approx. 8-10 mouthfuls of isotonic drink every 8-10mins of physical activity whilst sweating. If you are clearly not sweating, and don’t expect to sweat during the session then maybe water will suffice. A good way to go is to alternate an isotonic drink with regular water during sessions that aren’t causing you to sweat, the carbohydrate in the isotonic drink will enhance fluid absorption, energise you, whilst the electrolytes and fluid will help to maintain balance.
Del Coso, J., Gonzalez-Millan, C., Salinero, J, J., Abian-Vicen, J., Areces, F., Lledo, M., Lara, B., Gallo- Salazar, C., Ruiz- Vicente, D. (2015). Effects of oral salt supplementation on physical performance during a half- ironman: A randomised controlled trial. Scandinavian Journal of Medicine & Sciencein Sports (Epub ahead of print).