Prior to exercise, hydrate so that you start physical activities with normal hydration and electrolyte levels. Normal hydration is achieved when there has been adequate time since last exercise session and enough beverages consumed. Consuming liquids hours before you start exercising ensures that your urine output and body functions have returned to normal.

During exercise, monitor how you feel. If you are exercising at a high intensity for long periods of time, monitor weight changes. Consuming drinks that contain electrolytes and carbohydrates can be beneficial for some activities, dependent on the intensity and duration. Sodium in these beverages works to stimulate your thirst, carbohydrates for energy and general electrolyte replenishment.

After exercise, make sure to replace fluid and electrolyte losses by consuming regular meals and beverages over the next 24 hours. If you plan to exercise again sooner than that and feel significantly dehydrated, more focus will be needed to achieve rehydration. Drink 1.5 liters of fluid for every kilogram lost or 24 ounces for each pound. This rate of 150% of sweat losses is required because of the additional urine output that will occur from increased intake.