So, what are electrolytes?

You may have heard the word ‘electrolytes’ mentioned in connection with exercise, hydration and sports drinks; but what exactly are they? Do we really need them when we exercise?

Electrolytes are minerals that carry an electrical charge when dissolved in body fluids.  Some of the most important electrolytes include sodium, potassium, chloride, calcium and magnesium.

They play important roles in the body, including helping to regulate fluid balance and supporting normal muscle and nerve function (ACSM – American College of Sports Medicine).

Sodium is the main electrolyte lost in sweat, although sweat also contains other electrolytes. It’s useful to remind ourselves that, chloride, rather than chlorine, is the electrolyte found in body fluids and sweat.

What happens when we exercise?

When we exercise, our body produces heat, making us sweat, and this helps us to cool down. Sweat contains both water and electrolytes, particularly sodium and chloride. We also lose some water through our increased breathing. (Mayo Clinic Orthopedics)

The amount we lose can vary considerably from person to person. Someone exercising intensely in hot weather, for example, may lose considerably more fluid and sodium than someone taking a gentle walk in cooler conditions.

So, do we need electrolytes?

Sometimes — but not necessarily for every workout.

For many people doing a shorter or moderate workout, particularly in cooler conditions and without heavy sweating, water alongside a balanced diet will generally be sufficient. Electrolyte replacement may become more useful during prolonged exercise, heavy sweating, or exercise in hot or humid conditions.

Endurance activities such as long-distance running, cycling or hiking, can create greater fluid and electrolyte losses. (ACSM). On longer hikes, for example, fellow hikers and I, often take at least one bottle containing water mixed with an electrolyte powder. There are many flavours to enjoy.

Water or Electrolytes?

For everyday exercise, water is a great place to start.

If you’re doing a long or particularly sweaty workout, an electrolyte drink can help to replace some of the sodium and other electrolytes lost through sweating. You don’t necessarily need an expensive specialist product either; electrolytes are also found naturally in many foods and drinks (ACSM).

Also, remember, more isn’t always better. Drinking excessive amounts of fluid can also cause problems, including dangerously low blood sodium levels during prolonged exercise. It’s important to drink appropriately rather than simply trying to consume as much fluid as possible. (Mayo Clinic)

The Takeaway

Stay hydrated, listen to your body, and consider electrolytes when your workout demands them.

For a short, everyday workout, water will usually do the job. For longer, harder or particularly sweaty sessions, electrolytes may have a useful role in helping to replace some of the minerals lost through sweating.

If you’d prefer not to buy ready-made ‘packaged’ Electrolytes, there are some natural options; these include, coconut water, chocolate milk, and orange juice.

Hydration doesn’t have to be complicated; the aim is to drink appropriately for your activity, your environment, and, your individual needs. 💧

If you have a medical condition or take medication that affects fluid or electrolyte balance, speak with your healthcare professional before using electrolytes or significantly increasing electrolyte or sodium intake.

Research & Further Reading:

1. Baker (2017) — Sweating Rate and Sweat Sodium Concentration in Athletes: A Review of Methodology and Intra/Interindividual Variability. PubMed – Sweat Rate and Sweat Sodium Concentration

2. Baker et al. (2022) — Explaining variation in sweat sodium concentration: effect of individual characteristics and exercise, environmental, and dietary factors. PubMed – Variation in Sweat Sodium Concentration

3. Barnes et al. (2019) — Normative data for sweating rate, sweat sodium concentration, and sweat sodium loss in athletes: An update and analysis by sport.

PubMed – Sweat and Sodium Loss in Athletes

4. Rowland (1999) — Water and electrolyte requirements for exercise. Although older, this is useful for your distinction between shorter exercise, where water can often be sufficient

PubMed – Water and Electrolyte Requirements for Exercise

5. Hew-Butler et al. (2015) — Statement of the Third International Exercise-Associated Hyponatremia Consensus Development Conference. This provides strong support that drinking too much isn’t necessarily better, and, that exercise-associated hyponatremia can be dangerous.

PubMed – Exercise-Associated Hyponatremia Consensus Statement

6. Rowlands et al. (2022) — The Hydrating Effects of Hypertonic, Isotonic and Hypotonic Sports Drinks and Waters on Central Hydration During Continuous Exercise: A Systematic Meta-Analysis and Perspective. This examines drinking different types of carbohydrate-electrolyte drinks, and water, during continuous exercise. It includes 28 qualifying studies and 68 drink-treatment effects.

PubMed – Sports Drinks, Water and Hydration During Exercise

Disclaimer: The information provided is for general educational purposes only and is not intended to replace professional medical or healthcare advice. Before making changes to your diet, exercise or fitness routine, please consult a qualified healthcare professional to ensure they are appropriate for you.