← All supplements
Limited evidencePhysical performance

Salt Tablets

Sodium tablets for long, hot endurance events. One triathlon trial found a performance benefit, others found none, and salt tablets do not prevent the hyponatremia they are often taken for.

Where to buy

View on iHerb

Ships to 180+ countries · welcome discount for new customers

Referral link — this site may earn a commission on purchases.

What the science says

  • Performance benefit in a hot half-ironman Limited evidence

    A randomized controlled trial in half-ironman triathletes found oral salt supplementation improved race time compared with placebo, alongside better fluid balance. It is a single trial in a long event under heat stress.

  • No benefit in cooler or shorter exercise Moderate evidence

    A randomised crossover trial found sodium supplementation had no effect on cycling time-trial performance in cool conditions. Sweat sodium losses over shorter sessions are easily replaced by ordinary food.

  • Does not reliably prevent hyponatremia Limited evidence

    A prospective observational study of weight-based sodium supplementation in ultramarathon runners found no clear protection against dysnatremia or improvement in performance. Exercise-associated hyponatremia is driven mainly by drinking too much fluid, not by too little salt.

Dosage & safety

Studied doseStudies used roughly 1–2 g of sodium chloride per hour during prolonged exercise in heat, taken with adequate fluid. For sessions under about 90 minutes or in cool weather there is no established need.
SafetyTaking salt tablets with too little fluid causes nausea, vomiting and gastrointestinal distress; taking them with excessive fluid does not prevent hyponatremia. People with hypertension, heart failure or kidney disease should not use them without medical advice. Never use to treat symptoms of confusion or collapse during an event — that needs medical assessment.

How to take it

TimingOnly during prolonged exercise in the heat, spread through the session rather than taken all at once.
With food?Always with a substantial volume of fluid — a tablet on a dry stomach causes nausea and vomiting.
Worth knowingMatch the dose to how salty and how heavy your sweating actually is; most people under 90 minutes need nothing.

Interactions

With medications

  • lithium

    Sodium intake drives lithium clearance, so a sudden change in salt load can push lithium levels up or down. do not start regular salt tablets without telling the prescriber

  • antihypertensives and diuretics

    A large sodium load works against blood-pressure control and fluid management. talk to your doctor before using them

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Do salt tablets improve endurance performance?

Salt tablets have limited evidence for performance: one randomized trial in half-ironman triathletes racing in heat found improved race time versus placebo. Another trial found no effect on cycling time-trial performance in cool conditions (moderate evidence of no benefit there).

Do salt tablets prevent hyponatremia?

Salt tablets do not reliably prevent hyponatremia: an ultramarathon study of weight-based sodium supplementation found no clear protection against dysnatremia. Exercise-associated hyponatremia is driven mainly by drinking too much fluid, not by too little salt.

How many salt tablets should I take per hour?

Studies used roughly 1–2 g of sodium chloride per hour during prolonged exercise in heat, spread through the session and always taken with plenty of fluid. For sessions under about 90 minutes or in cool weather there is no established need for salt tablets.

Who should not take salt tablets?

People with hypertension, heart failure or kidney disease should not use salt tablets without medical advice, and a change in salt load can shift lithium levels. Taking salt tablets with too little fluid causes nausea and vomiting, and confusion or collapse during an event needs medical assessment, not more salt.

Scientific references

Related in Physical performance