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Do you ever wonder how much water or fluids you need each day to keep yourself hydrated, especially in the summer heat? Many of us grew up thinking we needed at least eight, eight-ounce glasses of water each day, or 64 ounces, to fulfill our daily fluid requirements. In reality, there really was no scientific evidence to support that recommendation but instead it was based on survey data of general consumption. Several studies and many years later, the recommendations for fluids have changed, but many of us are unaware of how much daily fluid intake we actually need to stay hydrated.

According to The Institute of Medicine, your water needs are dependent on many factors such as your:

  • Age

  • Health

  • Medications

  • Activity Level

  • Surrounding Climate

Two common ways to calculate your water needs are:

  1. Dietary Recommendations. The Institute of Medicine advises that healthy men consume roughly 125 ounces (about 15 cups) of total beverages a day and healthy women consume 91 ounces (about 11 cups) of total beverages a day.

  2. Replacement Approach. The average urine output for adults is about six cups per day. You lose approximately four more cups of water a day through breathing, sweating and bowel movements. Keeping in mind that food usually accounts for 20% of your total fluid intake, if you consume about eight additional cups of water along with your normal diet, you will typically replace your lost fluids and stay appropriately hydrated. .

In general, most experts agree that healthy adults may use thirst to determine their fluid needs. If you drink enough fluid so that you rarely feel thirsty and produce six cups or more of colorless or slightly yellow urine a day, your fluid intake is probably adequate. For our June Challenge, take this quiz to test your H2O knowledge, then pay attention to your thirst and track your fluid intake for at least one week to see if you are meeting the dietary guidelines for total fluid consumption.