February 18th, 2015
Water is a vital part of our body. Did you know that more than half of our body is water?
So, where is it hiding? Why can’t we see it? Well, just because we can’t see it doesn’t mean it’s not there. Apparent to the eyes, water is in our blood, urine (while it’s still in our body, it’s consider a part of us), saliva, tears and sweat. Water is also in many things that we can’t see, such as digestive juice and lymph. Still, all of those put together, it is still quite hard to believe water contributes to over 50% of our body, right?
Our organs like brain, heart, liver, lungs, skin, bones, muscles, stomach or intestines, are all made of micro organisms called “cells”. Each organ has its own kind of cell which differs in shape and function. However, the structure of all organs are pretty much the same, with genes on chromosomes in the middle part called nucleus, and plasma membrane that encloses it. There is fluid part in which these cell organels float around.
Cells also have water, although they are invisible to naked eyes. Over 80% of each cell is water, the percentage varying from cell type to cell type. Therefore, to stay healthy, we have to drink enough water regularly. Living organisms will be dead without water.
For people who do not exercise or are not in hot and humid environment in which the body sweats more than usual, drinking 10-12 glasses of water each day is recommended. Most of us only drink when we are thirsty. Actually, thirst is our body’s message that we are already dehydrated. Normally, when we feel thirsty, our body has lost 1-2% of water already. For example, a person who weighs 60 kilograms, losing 2% of body water means 100-120 cc or about a glass.
If we have lost water more than 2% of our body weight, the amount of blood in our body will also decrease, and the blood will become thicker when we exercise. The pulse will also become quicker and our body won’t be able to ventilate heat well. This means the body can’t tolerate much exercise or hard activities. Extreme dehydration can also result in fatigue, exhaustion and sleepiness.
Many elder people do not drink enough water because they do not want to go to the restroom often. Sometimes, they are not able to get up and grab a glass of water because of their physical condition. Dehydration in this age can add more risks for paralysis and Acute Myocardial Infarction.
Some people try to get enough daily fluid intake by drinking a lot of water in the morning. This is good, as the body loses a lot of water while we sleep, but drinking a lot of water just once or twice a day cannot prevent dehydration during the day.
Drinking plenty just once or twice is like pouring water on cracked soil in a plant pot. The soil cannot retain all that water for a long time. If you want to keep the soil moist all day long, you have to water it often.
Another group of people who could be dehydrated is sportsmen who work out heavily for an extended period of time. They sweat more than people in general. In the past, it was not recommended to drink water before exercise because it could cause abdominal pain. Now, the recommendation is drinking a glass or two about 30 minutes to an hour before exercise, and every 30 minutes during exercise.
It is very important to avoid exercising when the body is dehydrated as it could be hazardous, especially when the body has lost more water than 2% of body weight.
So, how do we know when we are dehydrated? Are we drying up too much before the workout? There are a few questions you should ask yourself.
Are you thirsty?
Is your urine very yellow?
Do you weigh less than of your weight 500 grams that morning?
If the answer to any of these is yes, then you are dehydrated. Get something to drink and wait 30 minutes to an hour before you start exercising.
In people who exercise hard, water needs to be replenished. Some people also sweat more than others. Generally, we lose 500 to 1,000 cc of water in an hour of exercise.
Therefore, for sweaty people or exercising people, don’t forget to replenish water loss by drinking water every 20-30 minutes during exercise. Post workout, your weight should decrease less than half a kilogram. For example, for a person who weighs 60 kilograms, if more than 500 grams is lost after workout, one or two glasses of water should be drunk to make up for they lost water. (Important note, the lost weight is mostly not fat. It’s water!)
If you want to exercise for your health without adding strain on your heart and blood system, make sure you understand the importance of water. It can be any kind of fluid – water or sport drink. If you prefer sport drink, watch out for carbohydrate(calories!!!) content. While you exercise, the body burns only a small amount of carbohydrate. Don’t celebrate the lost weight by adding carbohydrate to your body. Again, the lost weight is water, not fat.
Everything in moderation, that’s the key to good health.
Prof Nithi Mahanonda is consultant cardiologist and interventionist, Perfect Heart Institute.
ข้อคิดเห็นทั้งหมดนี้เป็นความคิดเห็นส่วนบุคคลของผู้อ่าน ไม่เกี่ยวข้องกับเจ้าของเว็บไซต์แต่อย่างใด โปรดแสดงความเห็นด้วยความสุภาพ ถ้าเป็นครั้งแรกที่คุณโพสต์แสดงความเห็น อาจจะมีการคัดกรองเนื้อหาได้ การแสดงความคิดเห็นควรอยู่ในประเด็น ห้ามโจมตีใส่ร้ายบุคคลอื่น หรือทำลิงค์ไปยังเว็บไซต์ที่มีเนื้อหาไม่เกี่ยวข้องกัน ผู้ดูแลเว็บไซต์สามารถแก้ไขหรือลบความคิดเห็นได้ทุกกรณี
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