What electrolytes are? How do they work? How do they benefit us? How do they power physical and mental performance? How much should we drink of it? Why can’t we just drink tap water? All these questions are answered in this 2 part article based on the blog of Ben Coomber, CISSN Performance Nutritionist and the founder of Awesome Supplements.

Electrolytes are essential, electrically-charged minerals (or salts). Their charge allows them to conduct signals along nerves, pull water into and out of cells and contract muscles. They play a vital role in hydration, muscular contraction and brain and nerve function.

The primary electrolytes involved in these processes include:

Sodium, potassium, calcium, magnesium, phosphorus

HYDRATION

The human body is made up of 50-75% of water. Two thirds of that is stored within our cells, the rest remains in the spaces between our cells or in our blood. Water flows passively. This means that, on its own, water will move freely until both sides of the cell membrane balance out. But to function optimally, we need twice as much inside our cells than outside.

This is where electrolytes become important. Their charge stops the water from passing freely into or out of the cell. Transporter channels control the exchange of electrolytes through the cell membrane. This maintains a concentration of salts that affects the water into the cell.

On average, we lose 2.3L of water per day (this will vary based on factors such as body weight, lean mass, hydration status, and activity level). Most of this is through urination. But other processes like breathing and sweating also cause fluid loss. So it’s important to replenish this water throughout the day. However, consuming too much fluid can flush out minerals by increasing urination. Fewer minerals means more water pulled out of cells to keep things balanced. This leads to cellular dehydration. When we sweat, we lose water and electrolytes (have you ever wondered why your sweat tastes salty?)

Cellular dehydration won’t only make you feel thirsty. It can lead to insulin resistance, cognitive impairment and brain tissue shrinkage.

PERFORMANCE

Electrolytes are important for physical activity by maintaining proper nerve and muscle function. This doesn’t just apply to long duration activity. Calcium and magnesium are crucial for muscle contraction and relaxation. This is why muscle cramps are a common sign of an electrolyte imbalance. They’re also involved in the electrical signal that causes your heart to beat.

If you’re low on electrolytes, your nerves can’t tell your muscles to work properly. Calcium is also crucial for force generation by allowing interaction between muscle fibres. So if strength is important to you, electrolytes are important to you.

Equally as relevant, electrolytes play a role in energy production. We need an electrical gradient to allow protons to pass into the mitochondria. This is how we produce ATP for energy. Low electrolyte levels will lead to increased fatigue and lower performance.

BRAIN FUNCTION

Dry mouth, sore head, difficulty of thinking and focusing, shaky body are all classic signs of dehydration and improper nerve and muscle function.

The electrical charge of electrolytes conduct a signal along nerves. If information can’t be passed through neurons to the hippocampus (memory storage area of the brain), then that information is lost. This results in gaps in memory.

WATER

Staying hydrated is clearly very important. Drinking water throughout the day is crucial. Bottled spring water and tap water contains very small amounts of minerals. Tap water is also treated with chemicals such as chlorine to remove bacteria. To get rid off the chemicals you can filter your tap water but it is likely that you are also removing any remaining minerals so it may be wise to replace the minerals in your filtered water with electrolytes.

You don’t need to consume electrolytes all day, every day. Too many electrolytes are as much of a problem as too little. The majority of your fluid intake should be from plain water. But if you follow the practical applications below, you’ll be better hydrated, and be optimising physical and mental potential.

PRACTICAL APPLICATIONS

How much fluid should you consume per day?

Most of our daily fluid intake comes from drinks. A small percentage will also come from the foods we eat. Foods have locked-in water. Fruits and vegetables have higher amounts than others (think of a juicy pear or a cucumber).

Most drinks we consume will contribute to hydration. Fruit juice, smoothies, tea, coffee (except espresso), even low percentage alcohol (eg. beers, wine). Hard spirits don’t contribute because their dehydration effect outweighs their volume of liquid. The most optimal is to get most of your daily hydration from water.

Drink to thirst. This is a good advice. Our bodies are good at self-regulating and will send thirst signals when water is low. But it can be easy to ignore thirst signals, or confuse them with hunger. So a more accurate estimate of your daily fluid requirements is as follows:

Daily Fluid Intake (mls) = Body Weight (kg) x 28

Add 500ml per 30 minutes of moderate-intense exercise.

Caffeine and alcohol increase fluid loss. When consume these drinks the kidneys reabsorbing less water, and passing more out as urine.

The diuretic (fluid loss) effect of most caffeinated drinks is neutralised by the volume of liquid. In other words, the amount of water or milk added to coffee drinks is usually enough to replace the extra fluid loss from the caffeine. This isn’t the case for espresso as there is a very low volume of water.

Also, caffeine and alcohol have a direct impact on sleep onset and sleep quality, and they crease the likelihood of waking for nocturnal urination. Avoid alcohol in the 2-3 hours before bed, and caffeine in the 8 hours leading up to sleep.

ELECTROLYTE SUPPLEMENTATION

How much of it should we have?

A good rule of thumb is to add electrolytes to water after periods of dehydration:

• Upon waking, after 7+ hours of zero hydration
• After, or during, moderate-to-intense physical activity
• On a hot day, if normal tasks are causing increased sweating
• After consuming alcohol
• If your normal water intake causes excessive urination