It was once thought that women who are nursing should drink two quarts of water a day to maintain a healthy milk supply. While remaining hydrated is important, it is not necessary to drink that much. Studies have show that being over hydrated may actually reduce milk supply.
A good rule of thumb is to drink enough to produce clear pale yellow urine. If your urine is concentrated or dark then it is a sign that you should increase your water intake.
Also, you don’t have to limit yourself to drinking water to stay hydrated. Fruit juices, milk, tea and water-based fruits and veggies are also good options.
If you’re working out while breastfeeding, be sure to drink extra water to replace what you lose in sweat. Try to keep your breasts dry and supported when doing physical activity by wearing an appropriate bra like Leading Lady’s sport wirefree nursing bra.