When I ask people about their hydration the most common reply is “ I drink a lot of water” Water is great but we need electrolytes, specifically sodium to properly hydrate as an active person. The amount of sodium needed varies person to person and the only exact way to know is to do a sweat test which are expense and not readily available so we have a few other ways to estimate what your level of sodium need will be.
The recommended daily intake of 2300mg is not for active people or athletes. You can easily use this in one long bout of exercise, especially my elite level and pros training in the heat! There is no blanket recommendation for sodium so how do you know how much sodium you need?
Ask yourself these questions:
How long are you working out?
How much do you sweat?
How hot/humid is the environment?
Do you leave white marks on your clothes after they dry?
What size are you?
It’s important to note that although we. need a balance of all electrolytes our main focus as an athlete should be replacing sodium we also need small amounts of potassium and magnesium but most sports drinks will add that in or you can get that from food. I usually look for 10% potassium to sodium.
When you look a a sports drink label you want to look at how much sodium is in the product. That's the most important part, many mixes only have 200mg or less.
Hydration and refueling during exercise is actually a pretty detailed science. Too much and you won’t be able to utilize the fuel properly, too little and you wont get enough fuel.
Gatorade has 220mg per 20oz bottle. That’s the minimum amount you would want per hour. (See my post on sports drinks).
Other products made specifically for active people such as Skratch, Precision Hydration, The Right Stuff and Gatorlytes have higher doses of sodium and the products really focused on athletes. Skrtach and Precision Hydration have a small dose of carbs as well. This is perfect mixed to have a 4-6% osmolality to be absorbed by your small intestine and go into your blood stream. If you have too many carbs and sodium you will cause water to flood into you intestine causing leaky gut.
Look at it this way- you can only hold so many molecules in your intestine before the balance throws things off.
Let me give you an example of how individual sodium loss can be. I sweat a lot and workout in a hot environment, but I’ve had a sweat test and I know that I don’t lose too much sodium when I sweat. This means I would need about 500mg/hr of sweat.
I like to look at it in 300-500mg increments. (Mostly b/c thats what’s on the market to buy). If I went by my sweat level alone I would think I was losing a ton of sodium but I don't leave salt marks on my clothes and I rarely cramp.
We can always start lower and titrate upwards depending up upon how you feel. Some signs to look for during exercise are dizziness, thirst, headaches and cramping
My only issue with starting too low is that most people I speak with have been working out with no added electrolytes . Which means they must feel ok with nothing, telling them to add little by little will usually yield too small of a dosage. I would start at 330mg per drink and go up from there.
Oftentimes I hear people say they drink coconut water for hydration- coconut water doesn’t work- It’s potassium. We need a small amount of potassium but what we are looking to replace is sodium. If you love cookout water you can add salt to the drink.
The magic between sodium and carbs:
These two are BFF when it comes to our body’s athletic output. Sodium helps pull carbs into the cell, (GLUT2 transporter) It ca actually increase the absorption of carbs a lot.
Sodium is used in muscle contraction.
Vitamin C uses sodium for transport:
The sodium-potassium adenosine triphosphatase (Na/K ATPase) pump closely regulates cellular electrolyte contents by actively pumping sodium out of cells in exchange for potassium.
Sodium transports glucose (carbs), amino acids, and other nutrients into the cells.
Vitamin C uses sodium for transport
A fun fact about salt, it is so important that the word 'salary' actually derives from the fact that Roman soldiers were often paid in salt.