Episode 130 – Electrolytes & Sports Performance

Key Topics Covered

Electrolyte supplement with exercise equipment.

  • Electrolytes matter for sports performance.
  • How much they matter and how much you should consume will be the focus of this episode.
  • A large proportion of the information is on sodium, partly because it is the one that is lost most through sweat. However, we will cover all 4 electrolytes.

Food vs Supplements

Foods with electrolytes

  • Sometimes people have certain products specifically for the electrolytes.
  • Examples:
  1. 600ml Gatorade has 300mg sodium, 135mg potassium, no magnesium and no calcium. 
  2. 1 tablet of Hydralyte has around 140mg sodium and 80mg potassium 

But when we compare that to food, it adds context.


  • 1x Muscle Chef Meal or similar typically contains >1000mg sodium. Typically more. So at minimum, it has >3x what a Gatorade has and >6x what a Hydralyte tablet has.
  • 1x medium potato contains ~600mg of potassium. So it is around 6x what those products contain.

That’s before even talking about the calcium and magnesium aspects. 

When you think of it like that, unless you are training for an exceptionally long period you can see how consuming electrolytes through food before exercising can make a huge difference

Performance Outcomes in Research for Sodium

  • A systematic review from 2018 on sodium and performance outcomes in endurance athletes only found 5 relevant studies.
  • One key aspect they highlighted was that a lot of guidelines mention the importance of sodium, but it is rare to see people give specific numbers, with rationale behind them.
  • Of the 5 studies, only 1 found improvement in performance.
  • That study found an 8% improvement in race times while using 500mg of sodium per hour. But that’s a bit of an outlier study, especially because 8% is a huge improvement.
  • Limitations identified in this review were that 1) It’s not much research 2) The duration of activities might not have been long enough 3) No studies featured >30 degree celsius weather.

Other Thoughts on Performance for Sodium

  • It would be hard to draw big conclusions from this review since there are a lot of gaps.
    • One gap was filled partly in a 2019 study, that compared low vs high sodium intake for 3 days.
    • The study involved 2 hours of endurance activity at a moderate intensity. 
    • The people in the low sodium group lost significantly more water weight during activity. Perceived effort was the same between groups though – and performance wasn’t measured since it was a set intensity.

Factors to Consider

  • 1) Sodium increases ad libitum fluid intake.
  • 2) Sodium helps reduce urinary output.
  • 3) In that specific study sweat rate was reduced substantially. 
  • This is very relevant because >2% fluid loss in the form of dehydration impacts performance.
  • Another underrated factor is that for long events, participants often feel the need to use the bathroom. So sodium reducing that urge could help improve performance a bit too.


Athlete with a cramp

  • We know that cramps and sodium CAN be linked because there is research showing that if you make people sweat heaps and then only give them water, they will start cramping.
  • Other studies have had people lose >2% of body mass through dehydration, then compared plain water vs water with electrolytes for rehydration. The water alone group cramped more.
  • So we have solid evidence that electrolytes CAN play a role in cramping.

Neuromuscular Fatigue Theory

  • From another perspective though, in athletes, the research indicates that electrolytes are rarely a factor in cramping. People who cramp consume similar amounts of electrolytes, have similar electrolyte levels, have similar sweat rates and compositions as those who do not cramp.
  • Cramps are far more commonly likely to be caused by what is called the neuromuscular fatigue theory. If you want more info on that episode 4 of the podcast discusses this in detail.
  • Note: Understanding neuromuscular fatigue is important for if self-identifying if other stuff contributes to cramping e.g. if you do the same activity two weeks in a row, you are less likely to cramp in week two than week one. 

Magnesium and Performance

  • Magnesium consumed pre or intra-training/event has not been shown to improve performance similarly to sodium. 
  • Exceptions to this would be cases of noticeable deficiency. For example, we know magnesium can help reduce cramping if people are quite deficient.
  • Indirectly, magnesium can help performance though. The majority of people do not consume enough magnesium. 
  • Higher dietary magnesium intake typically contributes to better sleep, better bone mineral density and there can be some other potential benefits too. 

Calcium + Potassium and Performance

  • This one is quick because I have not seen any research indicating that they directly contribute to performance.
  • Calcium of course could have indirect benefits through improved bone mineral density. 

Other Considerations

Muscle Pump

  • Sodium and/or potassium pre-workout can lead to better pumps in the gym due to more fluid being in the blood. This doesn’t affect performance much unless you are directly about to step on a bodybuilding stage.
  • Dizziness – Some people who experience dizziness related to low blood pressure can address this by having salt pre-workout. 
  • Safety during long events – It is rare, but hyponatremia is always a risk with long events. The body does have stores of sodium, so it is unlikely to run out. But if you drink heaps of water and have no electrolytes, there can be an imbalance coming in which can contribute to hyponatremia.
  • Rapid recovery/rehydration – if you need to rehydrate quickly between events, adding electrolytes can help you hold onto more of that fluid. 


Electrolytes and particularly sodium clearly matters for performance. However, there are only very specific circumstances where you may actually see performance improvements from this.

Relevant Blogs / Resources

Blog Posts

Studies Mentioned