THQ Trainer Posts – Hydration
By Jamie Thorne
Water makes up around 60-70% of our body weight, it is important to drink enough fluid to maintain a healthy balance of fluid within our body. On average the human body loses about 2.5 litres of water per day through sweat, urine and breathing. You also lose electrolytes and minerals like sodium and potassium. The exact amount lost varies depending on environment and activity level. Despite this many of us do not seriously consider the effects of hydration on our performance in the gym.
The carbohydrates and proteins we eat are metabolized and transported by water in the bloodstream, so without adequate water intake we cannot fully utilise our food. Your body can’t synthesise enough of its own fluid so we must consume water. When we exercise, we need blood to efficiently transport oxygen and the other essential nutrients and energy to allow us to exercise, if we are dehydrated our blood delivery can be less efficient therefore our physical output can decrease. Studies have also found dehydration can impact your mental game, findings show that dehydration can make exercise feel harder with an increased rate of perceived exhaustion (RPE).
Pre workout your main priority is to ensure that you are well hydrated. ACSM recommends drinking around 500 ml of fluid around 2 hours before exercise this can allow enough time for excretion of excess water, and an additional 125-250 ml immediately before exercise.
You will begin to lose fluid as soon as you start exercising so its important to offset any fluid loss by drinking early and at regular intervals. ACSM recommends 125-250 ml every 10-20 minutes while exercising.
Post workout the goal here is to replace any fluid lost during your session. The simplest way to track this is to weigh yourself before and after exercise. Research has shown that it is most beneficial to drink the equivalent of 1.5 times the amount of fluid lost. Working on the basis that 1 litre of sweat is equivalent to 1kg of body weight loss, you need to drink 1.5l per kg lost.
As the chart below shows the clearer your urine the more hydrated you are, the darker the more dehydrated you are.
When looking for an average daily intake many of the apps and websites use this formula:
- Your weight (kg) x 0.033
i.e. 85kg x 0.033 = 2.805 litres
Ultimately you should drink when you feel the need to, if you feel thirsty you need to drink. Our brain subconsciously tells us when we need to drink by making us feel ‘thirsty’ our brain is constantly monitoring everything and hydration level is a key indicator. Once we go below a certain level our brain tells us we are thirsty so don’t ignore it! In terms of how much fluid you need you need to look at the wider picture of your exercise needs, your work requirements and your body requirements.