Key takeaways

  • Most healthy adults don't need electrolyte supplements even in hot weather
  • Water, a balanced diet and thirst cues are usually enough hydration
  • Athletes, outdoor labourers and those exercising over an hour may benefit
  • People with kidney, heart or blood pressure conditions should ask a doctor first

With Portugal’s summers regularly bringing prolonged heatwaves, GPs are pushing back against the idea that everyone needs electrolyte drinks, powders or sachets to stay safely hydrated. Doctors interviewed on the topic say most healthy adults get enough sodium, potassium and other minerals through a normal diet, without needing extra supplements.

What electrolytes actually do

Electrolytes are minerals such as sodium, chloride, potassium, magnesium and calcium that carry an electrical charge in the body. According to GP Dr Oliver Rabie, their main job during hydration is to help the body retain water rather than acting as a hydrating substance themselves — sodium and glucose help pull water across the gut wall so it’s absorbed rather than urinated out.

The booming market for electrolyte products has been driven partly by wellness trends and partly by growth in endurance and high-intensity sports, doctors note. But that popularity doesn’t mean the products are necessary for everyone.

Who actually needs them

Doctors say the average person drinking reasonable amounts of water and eating a balanced diet doesn’t need extra electrolytes, even during hot weather, unless they’re sweating excessively. Outdoor manual workers, people exercising intensely in heat for more than an hour, and those recovering from vomiting or diarrhoea are the main groups likely to benefit.

For everyone else, water-rich foods like fruit, salads and soups, plus a varied diet including bananas, potatoes, spinach and yoghurt, typically supply enough of the electrolytes lost through sweat. People on blood pressure medication or with kidney or heart conditions are advised to check with a doctor before adding electrolyte supplements, since many are told to limit salt intake.

Staying safely hydrated in Portugal’s heat

For residents facing Portugal’s peak summer temperatures, especially inland and in the Alentejo or Algarve during heatwave spells, the practical advice is simple. Aim for 1.5 to 2 litres of water a day, rising to 2 to 2.5 litres on very hot days, and let thirst and urine colour guide you — pale urine generally signals adequate hydration, while dark yellow suggests it’s time to drink more.

Limiting alcohol, which has a dehydrating effect, and prioritising water-rich foods can help most people get through a heatwave without needing specialist products at all.