The workout water rules

It's important to stay adequately hydrated all the time, but it's particularly important when you're working out. Depending on how hard your workout is, you might sweat out a lot of water. Here are some water rules to follow, courtesy of Men's Health:

• Drink a glass of water 15 minutes before you start your workout
• For every 20 minutes you exercise, drink 8 oz of water
• Weight yourself before and after your workout and subtract the amount of water you've consumed. For every pound difference, drink 16 oz of water. And make sure you drink that much during your next workout too.
  
• The closer to clear your urine is, the better.
  

How much water do you drink during a workout?