Sodium is the primary mineral you will find in sports drinks, powders and tablets.
What role does sodium play in the body?
Sodium plays a critical role in your body, especially during exercise. Its functions include:
- Fluid Balance: Ensures fluids are correctly distributed throughout your body.
- Nerve Signals: Aids in the transmission of nerve impulses, affecting muscle contractions.
- Muscle Function: Plays a role in preventing cramps by balancing electrolytes.
What is the common dosage in sports products?
Sports products vary widely in their sodium content. Salt chews may provide around 100 mg of sodium per chew. Most electrolyte powders and drinks contain about 400 mg to 1000 mg of sodium per litre.
Some ‘saltier’ varieties contain up to 1,500 mg of sodium per litre, for salty sweaters.
To accurately measure sodium losses in your sweat, you can book a sweat test in a laboratory.
Identifying Sodium in Ingredient Lists
Sodium chloride (table salt), sodium citrate, sodium bicarbonate, sodium carbonate
Do I need sodium during prolonged exercise?
It can be a good idea to consume sodium during prolonged exercise, especially where sweat losses are high.
How much do I need?
It’s a difficult question to answer, because the amount of sodium that we lose through sweat varies greatly – not just between individuals, but also due to changes in your diet and environment.
The general recommendation is to consume about 500 to 1,000 mg of sodium per hour during prolonged exercise (usually over 2 hours).
You may be a very salty sweater – some tell-tale signs may be white salt streaks on your skin or clothes post exercise.
Salty sweaters can lose up to 2,000 mg of sodium per hour. In this case, you may need to aim for about 1,500 mg of sodium intake per hour.
Note that consuming high levels of sodium during exercise can also cause gut distress - so it can become a balancing act between replacing sodium and keeping your guts happy.
It’s not necessary to replace all sodium lost during exercise, but keeping on top of your sodium levels can stave off unwanted effects such as heat stress and muscle cramping.
Sodium’s role beyond hydration
Sodium plays another significant role in how your body handles energy during exercise, thanks to a process called Sodium-Glucose Co-transport.
Sodium-Glucose Co-transport
In your small intestine, a special protein (SGLT1) acts like glue, attaching one glucose molecule to two sodium ions. Together, they pass through the intestinal wall into your bloodstream. Why does this matter? Sodium acts like a magnet, pulling glucose into your bloodstream, so it is readily available to be used by your muscles for energy.
Sodium in our everyday diet
The advice from health organisations to limit sodium intake, typically around 2,000 mg per day, contrasts sharply with the needs of endurance athletes. This doesn’t mean that the guidelines are misplaced but highlights that your body’s needs change when you are exercising for extended periods.
Key takeaways:
- Customise your sodium intake: based on exercise intensity, sweat rate, and environmental conditions. Sodium losses are difficult to estimate without a proper sweat test, but if you are a noticeably salty sweater and/or suffer from muscle cramps, you could try adding a bit more sodium to your hydration during workouts (no more than 1,500 mg / hour).
- Listen to your body: most athletes consume sodium during exercise via a drink. Remember to drink to thirst, not to a schedule, to avoid overhydration or hyponatremia.
- Tip: Regular table salt contains about 40% sodium, 60% chloride. If you wanted to top-up your sodium intake, buy some basic micro-scales from TradeMe or Amazon, and weigh out what you need. Add it to your water, or top up your hydration powder. Easy. (1 gram table salt is about 400 mg sodium + 600 mg chloride).
