Water is an important nutrient for life because it helps regulate our temperature, lubricate our joints and transport nutrients throughout the body. Around 70% of our body weight is made up of water and it is vital to maintain that balance so that your body and mind can function correctly.
How much do you need to drink?
The European Food Safety Authority (EFSA) determined that women require 2 litres of liquids a day and men require 2.5 litres a day. So this is the absolute minimum you should be aiming to drink each day.
It is difficult to know what your levels of hydration are. Thirst can be a poor indicator of hydration status and therefore athletes should not rely on thirst alone.
A simple way to check that you are drinking enough fluid is to check the colour of your urine. The more transparent it is, the more hydrated you are. You should seek to produce urine that is ‘very pale yellow’, ‘pale yellow’ or ‘straw coloured’.
Hydrating when exercising
Staying hydrated is important for everyone, but athletes have an even greater need to maintain proper hydration. Performance can start to decline even with only 2% dehydration. It also makes your heart rate and body temperature spiral upward, making strenuous exercise tough to carry out.
During exercise, the physical effect of dehydration is that you get fatigued more easily, so every bit of effort feels harder and tougher. The mental effect is that you lose concentration, skill and accuracy. The combined effect is that you are going to end up in a situation where your performance will suffer. This can easily be avoided through effective hydration.
Why is water not enough?
86% of people drink water to hydrate when exercising but this is not the most effective way to stay hydrated. Your body needs electrolyte minerals, including sodium, potassium, calcium and magnesium, which you lose along with water when you sweat.
Prolonged heavy sweating can lead to significant mineral losses, particularly sodium. If you drink water, which has no electrolytes; you can dilute the concentration of remaining electrolyte minerals in your body. This imbalance means your performance is impaired.
Drinks containing electrolyte minerals improve the speed of absorption to the body, which is important when you need to rehydrate quickly, especially during strenuous exercise in the heat.
Your hydration strategy
There are 3 basic rules:
- Make sure you are well hydrated before you start your training or event or your performance will suffer. 400 to 600ml is a sufficient amount to take 3 to 4 hours before exercise. If you are participating in a demanding event, start paying attention to your hydration a couple of days in advance, to make sure you are optimally hydrated by the time you are on the starting line.
- Drink at regular intervals during exercise –. Take 3 to 4 sips every 10 minutes if possible, or 5 to 6 swallows every 15 minutes. Depending on exercise intensity, duration and temperature general guidelines are 500 ml to 1 litre per hour.
- Drink after you have finished. Iideally weigh yourself before and after exercise and for every 1/2 kg you lose, replace with 750ml of fluid. Don’t drink too fast – aim for around 500ml per half hour, allowing your body to hydrate at a reasonable rate.
Once rehydrated, do not forget your recovery product to help fatigued muscles recover quicker in time for your next session.