Personalized hydration

Personalized hydration refers to adjusting fluid and electrolyte intake to an individual’s sweat rate, sweat sodium concentration, and exercise conditions rather than following a one‑size‑fits‑all guideline.

Tailored fluid strategies

Athletes lose very different amounts of water and sodium during training. Research shows that sweat rates can range from about 0.3 to more than 5.7 litres per hour, and sweat sodium concentrations may vary from roughly 18 to over 70 mmol per litre. Many sports drinks supply around 20‑30 mEq sodium per litre and 4‑8% carbohydrate, which may not cover high losses. Drinking based solely on thirst often leads to under‑replacement of fluids and sodium, especially during long or intense sessions. Personalizing hydration involves estimating your own sweat rate by weighing yourself before and after a workout, taking note of environmental conditions, and understanding how much sodium you lose through sweat testing or general guidelines. Studies in team‑sport athletes show that plans tailored to an individual’s losses can improve anaerobic performance, attention, and heart rate recovery compared with ad libitum drinking.

Building your plan

To develop a hydration plan, monitor your body mass change during training to estimate fluid loss and aim to replace a portion of this during exercise and the remainder afterward. Choose or mix beverages that provide about 6‑8% carbohydrate and 500‑1000 mg sodium per litre (around 20‑30 mEq) and adjust the volume based on temperature and intensity. If your sweat sodium loss is high, salt capsules or electrolyte tablets can supplement a standard carbohydrate–electrolyte drink. On cooler, shorter sessions, drinking to thirst may suffice, but in hot or extended activities, a scheduled plan helps prevent excessive dehydration (>2% body mass loss). Avoid overdrinking, which can dilute blood sodium. Regularly reassess your sweat rate as fitness and climate change.

By tailoring hydration to your own physiology and environment, you can stay ahead of dehydration and maintain performance without the discomfort of overdrinking or the risk of hyponatremia.

Related Terms: Drink to thirst, Scheduled drinking, Salt capsules, Carbohydrate–electrolyte beverage, Carbohydrate concentration