Supplement Guide · Hydration
Electrolytes and Hydration: What to Look For
Hydration products have boomed, but most of the price difference between them comes down to one number: how much sodium they actually contain. Electrolytes — chiefly sodium, with potassium and magnesium — are what let your body hold onto water and maintain performance when you sweat.
Sodium is the headline electrolyte. Sweat is salty, and during long or hot training you can lose a lot of it. Effective hydration products provide a substantial sodium dose (often 500–1000mg per serving), whereas many supermarket tablets contain only a token amount and lean on sugar and flavour instead.
Potassium and magnesium play supporting roles in fluid balance and muscle function, so a good blend includes meaningful amounts of both. Be wary of products where the electrolyte content is tiny and the bulk of the serving is sugar or maltodextrin for taste.
Sugar is not automatically bad: during prolonged endurance work a little carbohydrate aids both fluid absorption and fuelling. For everyday hydration or shorter gym sessions, though, you usually want the electrolytes without the extra calories.
Match the product to the job: high-sodium formulas for heavy sweaters and endurance, lighter ones for daily top-ups. Our scores reward transparent, properly-dosed electrolyte content over sugar-and-flavour fillers.
Top Hydration picks
Ranked by The Lifting Lab Effectiveness Match score.
Frequently asked
What electrolytes matter most for hydration?
Sodium is the priority, supported by potassium and magnesium. Effective products often provide 500 to 1000mg of sodium per serving.
Do I need sugar in a hydration drink?
Only for prolonged endurance exercise, where some carbohydrate aids fluid absorption and fuelling. For everyday use you can skip it.
Why are some electrolyte tablets so cheap?
They usually contain only token amounts of sodium and rely on flavour and sugar, so they hydrate far less effectively than higher-dosed powders.
References
Sources behind this guide. Each was checked against the original publication.
- 1.Sawka MN, et al. (ACSM) (2007). American College of Sports Medicine position stand: exercise and fluid replacement. Med Sci Sports Exerc 39(2):377-390. View source
- 2.Baker LB (2017). Sweating rate and sweat sodium concentration in athletes: a review of methodology and intra/interindividual variability. Sports Med 47(Suppl 1):111-128. View source
- 3.Burke LM, et al. (2011). Carbohydrates for training and competition. J Sports Sci 29 Suppl 1:S17-27. View source
This guide is educational and not medical advice. For personal health concerns, or before starting any supplement that could affect a medical condition or medication, speak to a qualified clinician.