Whether you are finishing a demanding workout, walking in the summer heat, or simply getting through a busy day, your body relies on electrolytes to work properly.
These essential minerals help regulate hydration, support muscle movement, and carry messages through your nervous system. You lose them every day through sweat and urine, so replacing them is not only something to think about after exercise. Electrolytes matter on rest days, too.
Here, we explore what electrolytes are, what they do, and why they are so important.
Content outline
- What are electrolytes?
- What do electrolytes do?
- Which electrolytes does your body need?
- Why do you need electrolytes on workout days?
- Do you need electrolytes on non-workout days?
- How can you maintain your electrolyte balance?
- Summary
What are electrolytes?
Electrolytes are essential minerals needed to keep your body functioning. The main electrolytes your body needs are sodium, potassium, calcium, and magnesium. They are crucial for many important body functions, including maintaining fluid balance and supporting your muscles and nerves to work effectively [1]. Most of the time, your body keeps electrolytes in balance, but if they become too high or too low, it can interrupt some of their important functions, and in the most severe cases, can even be life-threatening.
Where do electrolytes come from?
Your body gets electrolytes from what you eat and drink. Your body will filter out excess electrolytes via the kidneys, but you can also lose them when you sweat, which is why during heavy workouts you may need an electrolyte drink to replace them. The same is true if you are sick or get diarrhea; you may need to replace the lost electrolytes to keep your body functioning as it should.
Good nutritious sources of electrolytes include:
|
Electrolyte |
Food sources |
|
Potassium |
avocado, bananas, milk, mushrooms, potatoes, salmon |
|
Sodium |
cheese, clams, table salt |
|
Magnesium |
almonds, brown rice, pumpkin seeds, spinach, tuna |
|
Calcium |
cheese, milk, spinach, tofu, yogurt |
What do electrolytes do?
Electrolytes are charged minerals that keep fluid levels balanced, support muscle contractions, and facilitate nerve signaling throughout the body.
They help maintain hydration
Hydration involves more than drinking water. Your body also needs the right concentration of electrolytes to move and retain fluid where it is needed.
Sodium and potassium are particularly important. Sodium helps regulate fluid outside your cells, while potassium plays a similar role inside them. Together, they help maintain the fluid balance required for healthy cell function.
They support your muscles
Your muscles need electrical signals to contract and relax. Electrolytes help carry these signals.
Calcium supports muscle contraction, while magnesium helps muscles relax afterward. Sodium and potassium also help generate the nerve impulses that tell your muscles when to move. This applies whether you are lifting weights, going for a run, or simply climbing the stairs.
They help your nervous system communicate
Your brain and nerves communicate through electrical impulses. Changes in sodium and potassium levels across cell membranes help create these impulses.
Without the correct electrolyte balance, messages may not travel between your brain and body as efficiently as they should.
They support a regular heartbeat
Your heart is a muscle, so it also relies on electrical activity and carefully controlled muscle contractions. Potassium, calcium, magnesium, and sodium all contribute to this process.
This is one reason why very high or very low electrolyte levels can be harmful. Electrolyte supplements should support your normal intake rather than provide excessive amounts.
Which electrolytes does your body need?
There are several key components that your body needs to maintain its electrolyte balance. Electrolytes can be positively (+) or negatively (-) charged. That’s because they are ions, which are atoms or molecules that have gained or lost electrons during chemical reactions or when dissolved in water.
For example, when sodium dissolves in fluids inside the body, it splits apart, leaving an unequal number of protons and electrons and creating a net electrical charge. It’s the electrical charge that helps your muscles contract and send signals between your nerves [2]. Simply, without electrolytes, you wouldn’t survive.
Sodium
Sodium helps regulate fluid balance, blood volume, nerve signals, and muscle contractions. It is also the main electrolyte lost in sweat and is a positively charged ion.
How much sodium you lose depends on factors such as:
-
how heavily you sweat
-
how long you exercise
-
the temperature and humidity
-
your clothing or protective equipment
-
your individual sweat composition
Some athletes may lose around 500 to 700 milligrams of sodium during an hour of vigorous exercise [3], although losses vary considerably between people. You can usually replace everyday losses through meals, but a drink mix may be convenient during longer or sweatier activities.
If your sodium levels fall too much, below 135 mmol/L, it can cause a condition called hyponatremia. Symptoms include:
-
headaches
-
confusion
-
feeling sick
-
delirium [4]
However, too much sodium can contribute to high blood pressure [4].
Potassium
Potassium is another positively charged electrolyte that works closely alongside sodium. For example, when a sodium ion enters a cell, a potassium ion leaves. This also happens the other way round and helps to regulate fluid balance, supports nerve transmission, muscle contraction, kidney function, and heart function [5].
Most adults should meet their general potassium needs through a balanced diet. The recommended daily amount is 3,400 milligrams for adult men and 2,600 milligrams for adult women, although individual needs can differ.
Magnesium
Magnesium is also positively charged and has important roles in energy production, muscle and nerve function, blood sugar regulation, and maintaining strong bones [6].
Too much or too little magnesium in the body can cause several health problems:
-
Hypomagnesemia – a condition caused by not having enough magnesium and can cause muscle weakness, twitching, and an abnormal heart rate or rhythm. Often occurs with calcium and potassium deficiencies.
-
Hypermagnesemia – occurs when there is too much magnesium in the body and can cause changes to your heart rhythm, reduced ability to breathe, and in severe cases, heart attack.
Calcium
Calcium is best known for supporting strong bones and teeth, but it also has an important role in muscle contraction, nerve signaling, and blood vessel function [7].
Dairy products, fortified plant-based drinks, canned fish with edible bones, tofu, and some green vegetables can provide calcium.
Why do you need electrolytes on workout days?
Exercise increases your fluid and electrolyte losses because your body produces sweat to cool itself. The longer or harder you exercise, and the hotter the conditions, the more you are likely to lose electrolytes, particularly sodium.
Replacing fluid and electrolytes may be especially useful if you:
-
exercise continuously for more than 60 minutes
-
train or compete in hot or humid weather
-
sweat heavily or notice salt marks on your clothing
-
complete several workouts in one day
-
work outdoors or wear heavy protective equipment
-
cannot eat a meal or snack soon after exercise
-
are recovering from an activity involving substantial sweat loss
However, not every workout requires a sports drink. Most people exercising for less than 60 to 90 minutes in normal conditions can usually maintain their electrolyte balance through water and regular meals. The goal is to match your hydration plan to your activity, environment, and sweat rate, not to consume as many electrolytes as possible.
Do you need electrolytes on non-workout days?
Yes, you still need electrolytes on rest days because your muscles, nerves, heart, and cells never stop using them. You also continue losing small amounts through urine and normal perspiration.
For most healthy people, food and water provide enough electrolytes on an ordinary rest day. However, extra attention to hydration may help when you:
-
spend several hours outdoors in hot weather
-
sweat while gardening or doing physical work
-
travel somewhere hot or at high altitude
-
have recently completed a demanding workout
-
follow a restricted diet
-
have difficulty drinking enough water
-
lose fluids through vomiting or diarrhea
Rest days also support recovery. Drinking regularly and eating balanced meals helps replace what you lost during training and prepares your body for its next workout.
How can you maintain your electrolyte balance?
The easiest way to maintain your electrolyte levels is by eating a healthy, balanced diet, drinking adequate amounts of water, and replacing lost minerals during strenuous exercise or illness. You can do this by eating nutrient- and electrolyte-rich foods, avoiding excessive water intake, and using electrolyte drinks when needed.
To help keep your electrolyte balance in check, you can try:
✅ Drink water regularly instead of waiting until you feel very thirsty
✅ Include fruits and vegetables in meals and snacks
✅ Eat potassium-rich foods such as potatoes, beans, bananas, and yogurt
✅ Include magnesium sources such as whole grains, nuts, seeds, and leafy greens
✅ Replace fluid gradually after a sweaty workout
✅ Consider an electrolyte drink, like Fiber-O-Lytes, during prolonged, intense, or hot-weather activity
✅ Avoid drinking excessive quantities of either plain water or electrolyte drinks
Summary
Electrolytes are essential minerals that have either a positive or negative electrical charge when dissolved in fluid. Key electrolytes include sodium, potassium, magnesium, and calcium. Together, they help to keep fluid levels balanced in the body, support muscle movement, and facilitate communication between nerves.
Fiber‑O‑Lytes from The Clear Jar combines electrolytes with 6 grams of soluble prebiotic fiber in a convenient, sugar-free drink mix. It offers a simple way to add electrolytes and fiber to your routine, whether you are preparing for a workout, replacing losses after a sweaty session, or supporting hydration on a busy rest day.
Explore the Fiber‑O‑Lytes range and find a flavor that fits easily into your day. Choose from watermelon, strawberry, or citrus flavours.
Written by: Leanne Edermaniger, M.Sc. Leanne is a professional science writer who specializes in writing about human health and wellbeing. Her work focuses on translating complex medical science into evidence-based, practical health guidance.
