BENEFITS AND LIMITATIONS TO PREHYDRATION

Athletes and others who begin exercise with a less than normal volume of they water are likely to experienceadverse effects on cardiovascular function, temperature reuglation, and exercise Perfonnance.. Increasing body water stores above nomal, well-hydlated levels by drinking fluids shortly before exercise isalso likely to cave caldiovascular function and temperature regulation When it is impossible to ingest sufficient fluids during exercise..Under most circumstances, it is wise to drink at least 500ml (16 oz) of fluid before sleeping on the nightbefore exercise and at least another 500 ml first thing in the morning to help ensure a state of euhydration.Next, one should drink another 500-1000ml about 1 h before and an additional 250-500ml about 20 minexercise to "top off" fluid stores.. The type of fluid consumed before exercise is important. Fluids containing carbohydrate (to supply energy)and small axnounts of sodium chloride (to help maintain thirst and reduce urine formation ) are likely tohave more beneficial effects than Plain water. The addition of glycerol to a Pre-exercise hydration beverageusually is ineffective and can produce headaches and nausea.