What does isotonic mean?
First up, let’s start with the basics – what even is isotonic? Well, the term ‘isotonic’ is used to describe a solution that is a similar ‘thickness’ to another solution.
In the context of sports drinks, an isotonic drink is a similar concentration, or tonicity to use the scientific term, to our blood. Our blood has an osmolarity of 280 – 300 mOsm/L and put simply osmolarity is the measurement for the concentration of the blood.
So, both isotonic sports drinks and our blood have an osmolarity of 280 – 300 mOsm/L, which means they have a similar concentration of water, carbohydrates, sugar, salt etc.
Why should I use isotonic drinks for sport?
The concentration, or tonicity, of a drink is important when it comes to sport or exercise because it impacts the amount of carbs, electrolytes and fluids that go into your bloodstream and how quickly they take effect.
Because isotonic drinks have a concentration similar to your blood, it means your body can quickly replace the fluid you’re losing through sweat and provide a boost of carbohydrate.
Why are fluids and carbohydrates important during sport?
Carbohydrates are your body’s fuel, giving you quick release energy to boost your endurance performance. Your body can only store enough carbohydrate for around 90 minutes of exercise and therefore you need to top up in order to stay at your best. Sports drinks are an easy way to do this while you’re on the go.
Similarly, staying hydrated is key to performing well. You actually lose more than one litre of fluid for every hour that you exercise and that fluid needs replacing. The fluid you lose is more than just water, it is water and electrolytes, key minerals that your body needs to function. Again, sports drinks typically contain electrolytes as well as water and carbohydrates.
Original Post Wiggle UK