Fluids matter for normal body function, and sweating during exercise or hot weather increases fluid loss. But drinking extra water does not treat an injury, prevent all cramps, or directly relieve muscle soreness.
Everyday hydration
For most people, regular drinks through the day are enough. NHS guidance suggests using thirst and pale-coloured urine as practical clues, while recognising needs vary with activity, heat, illness and individual circumstances. Water is a suitable choice; other drinks and some foods also contribute fluids.
During and after exercise
For a short, ordinary workout in mild conditions, most people do not need a special sports drink or electrolyte supplement. Longer sessions, hot conditions and heavy sweating can increase fluid needs. Drink to suit the conditions and your thirst; avoid forcing large volumes of water, particularly during prolonged exercise.
If you have been sweating heavily, replacing fluids with food and drink afterwards is usually practical. Electrolyte products are not automatically necessary. Individual advice may be appropriate for people with medical conditions or medicines that affect fluid balance.
When soreness needs a different response
Muscle soreness after unfamiliar or harder exercise often settles with time and normal activity adjustments. Hydration alone cannot distinguish routine soreness from an injury. Pause or modify exercise if pain is sharp, worsening, associated with significant swelling, or limiting normal use.
For general guidance, see the NHS hydration advice and our guides to returning to activity after injury and treatment options.