The effect of caffeinated, non-caffeinated, caloric and non-caloric beverages on hydration.

OBJECTIVE: To examine the effect of various combinations of beverages on hydration status in healthy free-living adult males. METHODS: In a counterbalanced, crossover manner, 18 healthy adult males ages 24 to 39, on four separate occasions, consumed water or water plus varying combinations of beverages. Clinical guidelines were used to determine the fluid allowance for [...]

Black tea–helpful or harmful? A review of the evidence.

OBJECTIVE: To consider whether consumption of black tea has a positive or negative impact on health. DESIGN: Databases were searched for relevant epidemiological and clinical studies published between 1990 and 2004. RESULTS: Clear evidence was found for coronary heart disease (CHD), where an intake of > or = 3 cups per day related to risk [...]

The effect of drinking tea at high altitude on hydration status and mood.

The effect of drinking tea on hydration status and mood was studied in nine male and four female members of expeditions based at Mt. Everest base camp at an altitude of 5,345 m. Whilst exposed to altitude-cold diuresis, participants were subjected to a crossover experimental design comprising two 24-h dietary interventions. In the "tea" condition, [...]

Caffeine vs caffeine-free sports drinks: effects on urine production at rest and during prolonged exercise

We compared the effects of caffeinated vs non-caffeinated carbohydrate electrolyte (CE) drinks on urine volume (UV), free water clearance (CH2O), fractional excretion of water (FEH2O), and osmolar excretion during 4 h of rest or 1 h rest followed by 3 h of cycling at 60% VO2max in six subjects. We also tested maximal performance at [...]