Rafa Barleze Reviewed October 5, 2026

Hydrate to compete.

Arrive prepared. Understand your losses. Match your intake to your session and the volume you can tolerate.

A plan that follows your day

Guidance for healthy adults. Ranges are a starting point; thirst, comfort, body mass and drinking opportunities guide adjustments.

  1. On waking

    Check thirst, urine and trends in morning body mass under similar conditions. One sign alone does not establish hydration status. Adding salt to water is not routinely necessary. [3] [2]

  2. 2–4 hours before

    Use 5–10 mL/kg as an initial reference, spread across this window. Account for previous intake, your meal, thirst and comfort. If already hydrated, do not force the upper end of the range. [1]

  3. Warm-up and half-time

    Keep drinks accessible and use breaks to drink according to your tested plan, thirst and tolerance. Avoid trying to catch up all at once. [2]

  4. During the match

    Use sweat rate to inform planning, not to force 100% replacement. Avoid body-mass gain from overdrinking. Losses around 2% are a useful caution point, especially in the heat, rather than a universal performance threshold. [2]

  5. After the match

    When rapid recovery is needed and a deficit remains, about 1.25–1.5 L per kg lost may help, spread over the following hours with food or a sodium-containing drink. With more time, normal meals and fluids may complete rehydration. [1]

  6. At night

    Spread intake so you do not need a large volume at bedtime. Nutritional recovery involves energy, carbohydrate and protein; this protocol neither requires whey nor excludes casein. [1]

Measure first. Adjust next.

These calculators estimate volumes; they do not diagnose dehydration or generate a prescription. Your entries stay on this page and are not sent.

Before exercise

A reference of 5–10 mL/kg in the preceding 2–4 hours. Include what you have already drunk in that window.

After exercise

An estimate of 125–150% of the deficit for rapid recovery over the following hours, with food or a sodium-containing drink.

Your sweat-rate test

Use the same scale and minimal dry clothing before and after a 30–120 min session. Dry off before the final weighing. Record all drinks and urine during that interval; avoid food during the test because its mass affects the estimate.

Sweat (L/h) = [(mass before − mass after) + drink (L) − urine (L)] ÷ duration (h).

This approximation treats 1 kg as 1 L and does not correct for all respiratory or metabolic losses. It does not measure sweat sodium. A negative result means the inputs need checking, not zero sweat.

[2]
How to interpret urine color

Lighter or darker urine is a clue, not a diagnosis. First-morning urine is often more concentrated; foods, supplements and medications can affect its color. Also consider thirst, urination frequency and body-mass trends. Do not drink to keep urine permanently clear.

[2]

Take your results with you

Generate a summary to discuss your plan. You can copy or print it; nothing is sent automatically.

What goes in your bottle

Sodium: consider fluid volume too

For prolonged exercise in the heat, the IOC consensus gives 400–850 mg sodium/L as a reference range. This is not mg/hour: 500 mL of a 600 mg/L drink provides 300 mg sodium. Adjust for context, food and fluid intake.

[4]

White marks on clothing do not quantify sodium loss. Replacing 100% of sodium losses is not a universal rule, and adding sodium does not make overdrinking safe.

[3] [5]

Carbohydrate: demands change the dose

Water is often enough for short, easy sessions. For prolonged efforts lasting 1–2.5 hours, 30–60 g carbohydrate/hour is a reference. Beyond 2.5 hours, up to 90 g/hour may help, using glucose and fructose with gut training and individual tolerance.

[1]

A 6–8% drink contains 6–8 g per 100 mL; it does not necessarily speed gastric emptying. In the heat, when hydration takes priority, more dilute drinks may be better tolerated. Include gels and food in total carbohydrate intake.

[4]
Products and anti-doping

Before using supplements and sports foods, review need, ingredients, sourcing and batch with your team. Independent batch testing, such as Informed Sport or NSF Certified for Sport, reduces risk but cannot guarantee zero risk. These seals are not a universal WADA requirement for every manufactured drink.

[6]

Know when to stop

Signs that need attention

Thirst, low urine output, fatigue, dizziness and headache can accompany dehydration but do not identify the cause on their own. Cramps are also multifactorial. Ease off, seek a cool place and reassess; persistent symptoms need medical attention.

[2]

Confusion or collapse is an emergency

Hyponatremia can occur from too much water or sports drink. Nausea, vomiting and headache after high intake require assessment. Confusion, seizures or collapse: stop exercise and seek emergency care. Do not force fluids or self-treat with salt. Body-mass gain raises suspicion, but its absence does not rule it out.

[5]

Kidney or heart disease, fluid/sodium restrictions and medicines affecting fluid balance require individual guidance. Children and adolescents need age-specific planning.

Evidence and limitations

Focused search updated October 5, 2026, including consensus statements, reviews and primary studies. This is not a systematic review. Earlier recommendations were retained where relevant, with contextual corrections.

A 2026 trial with 12 participants found no significant differences between water, a sodium/potassium drink and coconut water in the measured outcomes under controlled intake. The abstract was consulted; the small sample and specific protocol do not establish equivalence across sports.

[8]
  1. Thomas DT, Erdman KA, Burke LM. Nutrition and Athletic Performance. 2016 · Med Sci Sports Exerc.
  2. McDermott BP et al. National Athletic Trainers’ Association Position Statement: Fluid Replacement for the Physically Active. 2017 · J Athl Train.
  3. McCubbin AJ. Sodium intake for athletes before, during and after exercise: review and recommendations. 2025 · Performance Nutrition.
  4. Racinais S et al. IOC consensus statement on recommendations and regulations for sport events in the heat. 2023 · Br J Sports Med.
  5. Hew-Butler T et al. Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference, Carlsbad, California, 2015. 2015 · Br J Sports Med.
  6. Australian Institute of Sport. Additional Resources — Supplements.
  7. Borra V et al. Oral Rehydration Beverages for Treating Exercise-Associated Dehydration: A Systematic Review, Part I. Carbohydrate-Electrolyte Solutions. 2025 · J Athl Train.
  8. Killick JA et al. Comparing the Effects of Water, Sodium-Potassium, and Potassium-Rich Solutions on Fluid Balance and Thermal Strain Following Exercise in the Heat: A Randomized Triple-Blind Crossover Study. 2026 · Int J Sport Nutr Exerc Metab.

Full texts and relevant passages from consensus statements and reviews were consulted; recent studies with limited access were used only within the scope of their abstracts. Responses to drinks vary and evidence certainty is not uniform.

[7]