About 60% of our body is made up of water.
The brain, too, is about 75% water, and water plays many roles, such as supporting the work of nerve cells and maintaining blood flow.
In fact, several studies have reported that losing just 1 to 2% of body weight in water may reduce cognitive functions such as concentration, attention, short-term memory and work efficiency.
For a person who weighs 60 kg, for example, that means losing about 600 to 1,200 mL of water.
This is an amount of water you can lose even without intense exercise, simply by going out in midsummer or spending long hours in an air-conditioned room.
It is also said that by the time you feel thirsty, mild dehydration may already have begun.
In other words, your brain may be gradually affected even before you feel thirsty.
How Much Water Do You Need a Day?
So how much water should you actually drink?
The European Food Safety Authority (EFSA) sets the guideline for total daily water intake (water from both drinks and food combined) at
• Men: about 2.5 L
• Women: about 2.0 L
per day.
Since we also get water from food, the guideline for the amount to drink as beverages is around
• Men: about 2.0 L
• Women: about 1.6 L
per day.
Of course, these are only general guidelines.
On hot days, days when you exercise or days when you sweat a lot, you will need to drink more.
The key is to drink small amounts often, rather than a lot at once.
Dehydration Is Easy to Miss When You Are Working at a Desk
It may come as a surprise, but dehydration does not only happen when you are active outdoors.
When you are working at a desk or studying, concentrating on your tasks can make it harder to notice thirst.
In addition, in an air-conditioned room you hardly feel yourself sweating, so it is not uncommon to become dehydrated without realizing it.
“I can’t concentrate in the afternoon”
“My head feels heavy by the evening”
If this sounds like you, it may be worth looking not only at lack of sleep or fatigue but also at when you drink water.
Beyond Hydration, “Time to Rest Your Brain” Matters Too
Of course, the condition of your brain is not determined by water alone.
Enough sleep, proper rest and time to relax are also essential for keeping the brain healthy.
At La HEAD,
“I feel like my head is lighter after the treatment”
“It felt as if my thoughts had been sorted out”
are some of the comments we hear from our guests.
Amid the busyness of daily life, it can be surprisingly hard to consciously make time to rest your head.
In this season, when the heat makes it easy to get tired, why not make a habit of drinking water often, and also cherish time to let your brain and mind slowly rest?