Did you know that water makes up nearly 60% of our total body weight? (Enter the mental image of the Kool-Aid man! ) But seriously, we may not be giant walking glass pitchers but everything in our body contains water such as bone (22% water), muscle cells (75% water) and blood (83% water). Not only does water make up the bulk of our body, it has an essential role in making sure we’re functioning humans so it only makes sense to know a little something about proper hydration.
Water acts as a solvent (a liquid that can dissolve other solids, liquids or gases and transfer them throughout the body), as a transporter of nutrients to cells and remove of waste products, as a catalyst that speeds up enzymatic interactions with other chemicals, as a lubricant for joints, as a body temperature regulator, and as a mineral source.
It doesn’t take a Ph.D. to understand that all of those things are important and without a proper balance of fluid intake, you could be faced with some pretty serious consequences.
So…what exactly is fluid balance and why is it important? Fluid balance refers to the relationship of fluid you take in (through foods and liquids) and fluid you excrete (through sweat, respiration, feces, urination, etc.) Without a proper balance, you could be faced with dehydration, which we’ll talk about in just a bit, or hyponatremia, which is actually having too much water in the body relative to your sodium concentrations. (We’re only going to focus on dehydration for the purpose of this post.)
Fluid intake needs vary depending on body size, climate, and physical activity demands. A 250lb man will have a different need compared to a 120lb woman. A 200lb sedentary man that does not exercise will have different needs compared to a 200lb athlete that’s training 4-5 days a week. Or…a 120lb woman that trains in southern California with beautiful sunny blue skies may have different needs compared to a 120lb woman that trains in Philadelphia where the sun comes out on average 10 minutes a day and has been raining for the past 4 months… (I wouldn’t know how that feels at all, ugh!) A good rule of thumb to follow is for every kilogram (2.2lbs) of bodyweight you should consume approximately 30 – 40 mL (1 – 1.5 oz) of water. So if you weigh 110lbs, you should be drinking between 50 – 70 oz of water per day in addition to the water you’re getting from foods like raw fruits and veggies.
On average, a healthy adult loses water in several ways such as through insensible water loss (loss of water you cannot see or feel like respiration or evaporation from the skin), or through sweating during non-exercise conditions and while exercising, or through feces and urine.
Feeling thirsty yet? I am! Which leads me to my next point…thirst is actually a poor indicator of hydration since you’re not really “thirsty” until you’ve already experienced water loss. As little as a 1-2% reduction of body weight due to water loss can lead to changes in performance during activity and any additional loss can lead to illness and even death….no joke.
One of the most common consequences of having a body water imbalance is dehydration. I know…you know all about it, right? I can almost guarantee that the majority of you reading this right now don’t take in nearly enough water, myself included. Dehydration can be a result of things other than exercise too such as vomiting, diarrhea, fever/sweating, trauma or diuretics like coffee, tea or alcohol. Symptoms of dehydration are very similar to those of a hangover and include headaches, fatigue, low blood pressure, dizziness, fainting, nausea, rapid heart rate and constipation.
If you’re training hard on a regular basis, you’re also losing electrolytes as well as plasma which helps blood circulation. Without these two things, your heart has to work extra hard to pump blood through your body in order to produce the same cardiac output.
Electrolytes aren’t just some fancy thing you hear on Gatorade commercials either. They are minerals such as sodium, potassium, chloride, calcium, and magnesium that carry an electrical charge when dissolved in, you guessed it, water. Electrolytes are essential because they conduct electrical currents that enable fluid to pass through cellular membranes like transporters. Having an electrolyte balance in the body is equally as important as having a fluid balance in order to promote normal physiological function.
It’s important to replace both fluid and electrolytes as they’re both lost during respiration and sweat. Research studies have shown that a diluted carbohydrate drink that also contains electrolytes (like Gatorade or coconut water) is the best form of fluid replacement. The keyword here being diluted…anything greater than a 10% concentration in either carbohydrate or electrolyte will cause some GI discomfort and you may find yourself in the potty. Anything around 6-8% concentration is good. (We like good old fashioned Gatorade powder so you can actually measure the concentration compared to the bottles of Gatorade you can purchase almost anywhere.)
Why carbohydrates after training? Well, carbohydrates can improve the rate of fluid absorption and enhance endurance, increase your blood glucose, decrease stress response to training and improve immune function, decrease inflammatory damage and simply enhance whole body hydration. Carbs + Electrolytes = Match made in heaven!
Staying hydrated is pretty simple actually. For most people, approximately Two liters of water per day in addition to your normal food intake should be sufficient. You’ll get the most water from fresh raw fruits and vegetables as well as “wet” carbohydrates like cooked whole grains or legumes. Easy ways to make sure you’re getting enough water are things like attaching a new habit to an already existing one. For example, I’ve been taking a fish oil supplement each night before bed so I’ve attached drinking 8 oz of water to that just to get in more hydration before bed. Give it a try! Not sure if you’re adequately hydrated? A quick pee check will help too!
When exercising, things are a little different. It’s important to start the hydration process even before you begin training. The recommendation is to consume 500 mL (approximately 17oz) of fluid 30 minutes prior to training. I wouldn’t count 300 mg of caffeine in that pre-workout either. Replacing fluid and electrolytes during exercise is important in order to maintain the same level of performance too. This will obviously vary depending on body size, climate and the intensity, however, we recommend 250 mL (approximately 8.5 oz) every 15 minutes of exercise.
Another great intra and post workout hydration tip…don’t forget about protein! You know we’re always preaching about protein intake and here’s just another great example of how crucial it is. In addition to fluids, carbohydrates, and electrolytes, protein intake during and after training has shown to enhance muscle protein synthesis, improve recovery, reduce muscle soreness and decrease protein breakdown. It’s a win-win! For every hour of training, you should aim to consume a combination of 30g of carbohydrate + electrolyte and 15g of protein in 600 mL of water (approximately 20oz). Oh and don’t slam this back either unless you want to spend the next 20 minutes in and out of the bathroom.
So whether you’re standing around the office, training for your next competition or vacationing in Mexico, understand that there’s a reason why your mom, your coach and your doctor were always telling you to drink enough water! Cheers!