Hydration is all about balance
Hydration is all about fluid balance:
Fluid balance is the relationship between fluid coming in (mostly from food and drinks) and out (from sweating, breathing, excreting, vomiting) of your body.
How much fluid do we lose?
Breathing and skin evaporation: Our nasal passages and lungs moisten the air that we breath and we’re always losing water through evaporation our skin, though we can’t feel it like sweating. These process cause around 650-850 mL of loss every 24 hours.
Excretion: WE lose fluid through both feces and urine. An average adult needs an absolute minimum of about ½ L water per day for healthy kidney function. At this low intake, you put yourself at risk of kidney stones and other problems due to the high concentration of your urine.
Lack of water also causes constipation, conversely diarrhea causes significant loss of fluid.
Sweating: During intense exercise, especially in hot climates, we can lose quite a lot of water. In general, we sweat around 0.5-2.0L per hour of activity.
How much fluid do we need?
Depending on what you eat, you can get about 4 cups of water from the foods you are eating on a daily basis.
Raw fruits and vegetables contain mostly water
Cooked grains and legumes contain some water when they absorb water through the cooking process.
High fat foods like nuts, seeds, oils and butter have very little water (which is why hydration is so important on a Ketogenic diet).
While we get some water from food, most of our fluid intake comes from what we drink. The body will regulate thirst to take in more water when we need it.
You are likely to feel more thirsty when:
The temperature is warmer
The humidity is lower
You’ve eaten something salty
You’ve consumed alcohol
You’ve been sweating
You are likely to feel less thirsty when:
It’s cooler
It’s humid
You haven’t sweated much
There’s generally a lag time between losing fluid and the body triggering thirst. Staying ahead of dehydration becomes important for all people but it becomes possibly life saving when exercising or working in extreme conditions as even slight dehydration can worsen thinking, focusing, and performance. Next week we’ll get into how much you should be drinking, but in the meantime… don’t wait to feel thirsty before you have your first glass of water for the day!
