Staying hydrated is critical to any endurance athlete. Leading up to my race on Sunday, I’ve been making an effort on getting plenty of water this week. You can’t just drink a lot of water the day before, it takes several days to properly hydrate before a long race.
Every day you lose water through your breath, perspiration, urine and bowel movements. For your body to function properly, you must replenish its water supply by consuming beverages and foods that contain water.
Several approaches attempt to approximate water needs for the average, healthy adult living in a temperate climate.
* Replacement approach. The average urine output for adults is about 1.5 liters (6.3 cups) a day. You lose close to an additional liter of water a day through breathing, sweating and bowel movements. Food usually accounts for 20 percent of your total fluid intake, so if you consume 2 liters of water or other beverages a day (a little more than 8 cups) along with your normal diet, you will typically replace the lost fluids.
* Eight 8-ounce glasses of water a day. Another approach to water intake is the “8 x 8 rule” — drink eight 8-ounce glasses of water a day (about 1.9 liters). The rule could also be stated, “drink eight 8-ounce glasses of fluid a day,” as all fluids count toward the daily total. Though the approach isn’t supported by scientific evidence, many people use this basic rule as a guideline for how much water and other fluids to drink.
* Dietary recommendations. The Institute of Medicine advises that men consume roughly 3 liters (about 13 cups) of total beverages a day and women consume 2.2 liters (about 9 cups) of total beverages a day.
It’s kind of gross, but the bottom line is to just look at your urine. If it’s colorless or slightly yellow, your fluid intake is probably adequate.