Electrolytes
Water alone does not rehydrate you after heavy sweating. Sodium drives fluid retention, and potassium and magnesium support muscle and nerve function.
Effective dose
300–1,000 mg sodium per hour of hard or hot training, adjusted to sweat rate.
Timing
During and immediately after training; also useful first thing on hot days.
What it is
Minerals that carry an electrical charge in body fluid. Sodium is the one you lose most of in sweat, typically 500–1,500 mg per litre.
How it works
Sodium maintains blood volume and pulls water into circulation rather than straight through you. Without it, a large water intake can dilute blood sodium and make you feel worse.
What the research shows
- Sodium-containing fluids restore hydration status better than plain water after significant sweat loss.
- Cramping is multifactorial, but heavy, salty sweaters tend to benefit most from added sodium.
Best for
Forms to look for
- Sugar-free electrolyte sticks
- Sports drinks with carbohydrate
- Salt capsules
What to watch out for
Most 'hydration' powders are mostly flavour. Check the actual sodium number on the label.
Sourcing partners
Coming soonWe are onboarding a short list of vetted suppliers for electrolytes, each with published certificates of analysis and third-party identity testing. Direct purchasing will open here once those partners are live.
FAQs
Do I need electrolytes for a 45-minute gym session?
Usually not, unless it is hot, you sweat heavily, or you train fasted. Water is fine for most indoor sessions.
Related on SportsNutrition.com
Educational information only, not medical advice. Talk to your physician or a registered dietitian before starting a supplement, especially if you are pregnant, nursing, managing a health condition, or taking medication.