Isotonic drinks and hydration: finding the right balance for marathon runners

Running a marathon is a real challenge both physically and mentally. hydration is very important for a runner to perform at their best during this sustained exercise. One of the solutions to meet this need is isotonic drinks. But how much? How to find the right balance between water and isotonic drinks?

Prevent dehydration – the marathon runner’s enemy

Electrolytes are minerals in the body that have an electrical charge (positive or negative, like a battery). They play a vital role in the functioning of cells and muscles both at rest and during exercise. You probably know the main electrolytes – sodium, potassium, calcium and magnesium.

What can lead to dehydration during a marathon?

Dehydration during a marathon is a very common and avoidable problem. A body that is seriously challenged during exercise undergoes significant changes. Because when athletes do long distances, it is inevitable – the body produces heat.

Since the body is homeothermic, it will try at all costs to return to normal body temperature to avoid overheating. Where can difficulties arise? These interrelated mechanisms of rebalancing are likely to lead to severe sehydration. What are these mechanisms –

Sweating: the body evaporates water through sweating;
Respiration: Runners exhale hot, humid air during exercise, resulting in significant water loss;
Electrolyte Loss: Sweating not only causes fluid loss, but also electrolytes (sodium, potassium, magnesium). These minerals help maintain adequate water levels inside and outside the cells. As these are lost, water loss is promoted, also leading to dehydration.
In addition to physiological mechanisms, other factors should not be forgotten: duration of exercise and environmental conditions (high heat, humidity, altitude, etc.).

How can I recognize the signs of dehydration?

Even though it would be best to prevent dehydration altogether, every runner should recognize the signs of dehydration if it does occur:

Strong thirst: this is one of the first signs that the body signals;
Heart rate increases: the heart tries to compensate for the decrease in blood volume;
Faster Breathing;
Low blood pressure;
Headache;
Muscle Cramps
Feeling and fatigue .

If you notice any of these symptoms during the marathon, stop and, in more serious cases, seek immediate medical attention.

How does dehydration affect athletic performance?

In addition to the health effects of lack of hydration, performance is also affected.

The muscles activated during running receive less nutrients, oxygen and electrolytes, all of which are necessary for their proper functioning and efficient muscle contraction. The result? Muscle cramps, pain and loss of strength, which often affects your finish time.

Furthermore, dehydration reduces oxygen circulation, making general circulation less efficient – you get tired faster.

It should be noted, however, that according to certain scientific studies, mild to moderate dehydration does not automatically lead to decreased performance, although it may contribute to it. In addition to affecting your performance, dehydration can cause serious health risks (headaches, fatigue, dizziness, muscle weakness, constipation, high heart rate, kidney failure, etc.).

Plain water and isotonic drinks: what are the differences?

Plain water and isotonic drinks are not the same: they do not have the same composition, purpose or application.

Plain water is just that – water, with no additives. On the other hand, isotonic drinks contain carbohydrates and electrolytes. They may also contain vitamins, flavorings and other ingredients that give them additional properties.

If everyday water is intended simply for liquid intake, then the purpose of isotonic drinks is to provide the body with liquid faster, while providing additional benefits during exercise: energy, electrolytes, etc.

Therefore, for regular daily hydration and during exercise of less than 1 hour in not too hot conditions, you can use plain water, while isotonic drinks should be taken before, during and/or after intense and prolonged exercise.

What are the benefits of an isotonic drink?

Prevents hyponatremia and increases electrolytes

Isotonic drinks contain electrolytes such as sodium, potassium and magnesium, which are essential for the body’s internal balance. Drinking plain water to avoid dehydration does not always replenish electrolytes sufficiently. This can lead to hyponatremia ie. an abnormally low level of sodium in the blood compared to the amount in water.

The first symptoms of hyponatremia are dizziness, swollen hands, confusion and nausea.

Isotonic drinks enriched with sodium are specially designed to replenish electrolytes lost through sweating.

Increases energy with carbohydrates

Isotonic drinks often contain simple carbohydrates, which are easily digested and assimilated by the body. Therefore, they are quickly used as a source of energy during sustained loads.

By consuming this type of drink, you help yourself to avoid the risk of hypoglycemia , maintain stamina and delay muscle fatigue by providing a constant source of energy.

Improves water absorption for faster hydration

The composition and osmolarity of isotonic drinks is similar to blood and body fluids.

Osmolarity indicates the total concentration of dissolved particles in a liquid. This similarity promotes faster absorption of electrolytes and carbohydrates, making it particularly effective for rapid hydration compared to a hypotonic beverage such as tap water.

Which sports drink should I choose?

The choice available in the market is very wide. Pay attention to the composition of the sports drink. Choose drinks that also contain electrolytes.

They can differ in form – they can be in liquid form, they can be powder or tablets that need to be dissolved in water. Did you know that ISOSTAR is the founder of isotonic drinks ? Choose the most suitable way of taking electrolytes, vitamins and carbohydrates from our assortment – Powertabs dissolving tablets, one of Hydrate & Perform series powders, Endurance+ endurance series powders for longer loads or prepare Fast Hydration drink. Any of these ISOSTAR isotonic category products will help you ensure optimal hydration, as well as take in additional vitamins, minerals and gain energy. All you have to do is choose the type and taste you like best!

In any case, it’s important to test your energy drink during pre-marathon training to see if it’s right for you in terms of taste, effectiveness and digestive tolerance.