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​Do I need extra Electrolytes?

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One of the key aspects of training and racing endurance events is the area of electrolytes. Most triathletes say it is the 4th leg of a triathlon. It is equally important for running, cycling and any exercise lasting over say 1 hour.

I am often asked: “What sports drink or energy drink should I take while exercising?” The article below touches on some of the basics regarding sports hydration. You should read it as a start on your journey to better understanding your specific needs and choice of electrolytes,

Most often people are focused on the taste rather than the composition. Although taste is important (psychologically you will drink more if you like it), the real importance is getting enough electrolytes to help you perform (and recover) your best. Sweat rates can vary over 10 times between individuals so thinking about your needs and a good solution really makes a positive impact.

What are electrolytes?

There are 5 major electrolytes - Sodium (Na+), Chloride (Cl-), Potassium (K+), Magnesium (Mg++), Calcium (Ca++) and 2 minor ones - Phosphate (HPO4–), Bicarbonate (HCO3-) that you need balance in your body for optimal performance (and health).

Electrolytes in your body carry electrical charges that are responsible for stimulating muscles and nerves. They also regulate the amount of fluids throughout your body, which affects cellular function, blood volume and blood pressure. So, the simple version is that you need them, the longer version dealing with the underlying chemistry is left for homework (or a degree!)

How much do I need?

The answer to this question is “depends”. It really depends on your sweat rate and how you’re you sweat certain electrolytes. The belief is that your genetics is the major indicator of sweat rate and electrolyte use.

You can (and should) determine your electrolyte use through a scientific sweat test to get the most accuracy. These tests can determine how much sweat you lose and more importantly how many electrolytes you use in your sweat. As noted above the difference in individuals can be more than 10 times. For example, I am a heavy sweater, so I lose a lot of fluid per hour but also lose lots of sodium (and the other electrolytes). So, I might lose a litre of fluid and about 1500mg/l of sodium. Conversely, my training partner (similar size and training intensity) loses less than 500ml fluid per hour and below 800mg/l.

The unscientific method can also help you start down the path to better electrolyte replacement. Measuring yourself before/after a session and categorizing your sweat as heavy salt to low salt gives you some indication of how much needs to be replaced.

As an indication the average person can lose about 1000mg/l of sodium and 150mg of potassium per hour of vigorous exercise.

Can I replace naturally?

I think most people agree that the best way to stay healthy is based on a good diet. Electrolytes are no different and can be replaced naturally replace before and after exercise. For example, plant-based foods, apples, corn, beets, carrots and green beans, are all rich in electrolytes. Other electrolyte-laden fruits and veggies include limes, lemons, oranges, sweet potatoes, artichokes, all types of squash and tomatoes.

Hence there are plenty of natural based solutions to getting enough electrolytes. The problem, of course, comes during heavy exercise where you need to replace a lot, or you don’t have a bag of apples and beets in your feed bag!!

What about Electrolyte tablets?

These are a must do for exercise time. As mentioned previously you need to replace a lot and use fruit and veggies is not enough.

Sports drinks on their own generally are not enough (or they contain nutrition) so you are better to formulate a strategy based on your needs using sports electrolyte replacement tablets (or powder). You still need to read the labelling to ensure you are getting enough of the right electrolytes as the quantities vary. For example, 4 of the more popular solutions using standard mixes have the following sodium content – High5 Zero (500mg/l), Pure Electrolyte Hydration (580mg/l), Gu Brew (640 mg/l) and Nuun (720mg/l) – over 40% difference and more importantly none would replace enough sodium of the average or heavy sweater!


In my opinion, researching and learning about your electrolyte replacement needs is as important as turning up for a training session. This is especially true for endurance athletes in events like triathlon marathon running and cycling. Your plan can be unscientific and based on reading the signs of your body and always improving. Start with the assumption that you are probably not hydrating enough and not replacing enough electrolytes – so do more! As you become more involved in your sport progress to the more scientific analysis of your needs and determining which product and quantities will meet your needs. Then focus on the taste!

About the author

Andrew Lang has been competing in triathlons for over 20 years and all distances from Sprint all the way up to completing 19 Ironman triathlons. Although he is a middle to back of the pack triathlete he has been fortunate to race at 2 Ironman 70.3 World Championships and the Ironman World Champions at Kona. Since 2009, Andrew has owned and operated Ezi Sports – the largest online triathlon store in Australia. He gets to field test and evaluate most new products on the market as well as help thousands of athletes with their sport gear needs.