Health and hydration: 5 reasons to drink up
When you're drenched in sweat after a 10k run or are trying to survive a hot summer day, sipping on water is more than a refreshing sip—it's a necessity. Water is crucial to many of your body's processes, and without proper hydration, especially during exercise or rising temps, your body won't function as efficiently as it should.
We’re breaking down why hydration is essential and how much you should drink.
Why hydration matters
From increased alertness and improved physical performance to better digestive health, it all starts with proper hydration.
1. Cognitive function
Struggling with slow reactions, short-term memory, or staying focused? You might be dehydrated. Even mild dehydration—between 1-2% body water loss—can impact cognitive performance, including:
- Decreased alertness
- Poor concentration
- Increased moodiness
- Decreased critical thinking
Water is vital for proper brain and cognitive functioning. It aids in neurotransmitter production and function, facilitating communication between brain cells.
2. Physical performance
Like with cognitive performance, even mild dehydration can reduce your performance in the gym.
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Muscle function. During exercise, dehydration can decrease blood flow to your muscles due to reduced blood pressure. This reduction can compromise muscle performance, endurance, and strength, plus increase fatigue.
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Oxygen delivery. Sarah Eby, MD, PhD, from Mass General Brigham, explains that dehydration "thickens the blood and affects the blood’s oxygen-carrying capacity. This lowers the amount of oxygen that your muscles get," which can affect your physical performance.
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Body temperature regulation. Hydration is essential to maintaining your body temperature, especially during exercise or hot weather. Sweating is how your body cools down, but if you don't replenish the water you lose from sweating, it won't be enough to offset the increase in body temperature.
- Joint lubrication. Water is a major part of synovial fluid (SF), which lubricates joints and prevents bones from rubbing together. Hydration improves SF production and maintains cartilage shock absorbency, which can help maintain joint flexibility and reduce your risk of injury.
3. Kidney function
Your kidneys regulate fluid balance and act as the body's natural filter. But they need water to help remove waste from your blood and excrete it through urine. Water makes the filtration process run smoothly, flushing out toxins and waste products—ultimately supporting healthy kidney function.
4. Digestive health
Water makes your body work. It aids in proper digestion, passing waste, absorbing nutrients, and supporting metabolic processes:
- Food breakdown. Digestion starts with water—specifically, saliva, which breaks down food so you can absorb nutrients.
- Metabolic support. Water aids in metabolic processes, like metabolizing stored fat into energy.
- Digestive tract lubrication. Water lubricates your digestive tract to help food move through it.
- Stool support. Water can prevent constipation by softening stool, making it easier to pass.
5. Nutrient transportation
Blood—which is mostly water—is responsible for everything from transporting oxygen to your lungs and removing waste products to regulating your body temperature. It's your body's transport system, sending nutrients, hormones, and oxygen to cells, promoting healthy cellular function.
Without proper hydration, your blood can't do its many jobs in your body.
How much you should drink for ideal hydration
You've probably heard, "Drink eight cups a day." It's an old adage to encourage us to drink enough water. But is it still accurate? Maybe not.
While hydration suggestions aren't one-size-fits-all, a general rule of thumb is to divide your body weight in half and drink that many ounces of water. So, if you weigh 140 pounds, you should drink about 70 ounces of water daily.
Nearly 60% of your body weight is water. Because we all have different weights, the amount of water in our bodies varies, too. Using the body weight formula to understand hydration needs allows for a more personalized recommendation based on your weight.
Hydration by activity level
To cool your body down during workouts, your body sweats. This extra water loss requires more hydration to replenish what was lost, which is why athletes typically need to drink more water and electrolytes than sedentary people.
Another reason more active individuals need to drink more water is because they may have more muscle. Muscle mass is mostly water—between 70 and 75%—whereas fat is only between 10 and 40% water. With muscle holding significantly more water than fat, two people who weigh the same but have different body compositions will have different hydration needs.
The American College of Sports Medicine suggests adding 8-16 ounces of water for every 30 minutes you plan to work out.
Drink up
Improved digestion. Better focus. Enhanced physical performance. There are many to stay hydrated, especially if you're an athlete or enjoy your gym sessions. But we get it—getting enough water every day is tough.
Bored with the lack of flavor? Add fruit to your water to flavor it naturally. And if you struggle to get enough, carry a refillable water bottle to guarantee you stay hydrated throughout the day.
Drink up!