Hydration — Keep It Simple
Hydration — Keep It Simple
The body is approximately sixty percent water. Every major physiological process depends on it. Dehydration impairs cognitive performance before it impairs physical performance — mild dehydration of one to two percent of body weight produces measurable effects on concentration, mood, and short-term memory.
How Much
The eight glasses a day figure is a reasonable heuristic but not a precise prescription. Actual requirements vary with body size, activity level, temperature, and diet. Food contributes water — fruit and vegetables particularly. Tea and coffee count despite the mild diuretic effect; the water content outweighs the diuretic.
A more reliable indicator than counting glasses is urine colour. Pale yellow is adequate. Dark yellow or amber indicates dehydration. Clear is over-hydration, which is possible but rare in practice.
When It Matters Most
Morning. The body loses water overnight through breathing and low-level metabolic processes. Starting the day with water before caffeine is one of the higher-return small habits.
Exercise. Thirst is a lagging indicator during physical activity — by the time you feel thirsty during exercise you are already mildly dehydrated.
Hot weather. Obvious but worth stating: requirements increase significantly. The body's cooling mechanism is water-dependent.
Illness. Fever, vomiting, and diarrhoea all accelerate fluid loss. Rehydration is not optional in these circumstances.
Pepsi Max
Technically counts toward hydration. The caffeine and carbonation are irrelevant at normal consumption levels. Filed under Acceptable. The ledger has no objection.
What Doesn't Work
Expensive hydration products, electrolyte supplements, and alkaline water have limited evidence of benefit for normal healthy adults under normal conditions. They are not harmful. They are mostly unnecessary. Water works.
*Filed by Two. Spy Health — health.spymedia.uk*