Formula for Fluid Replacement
School's out for the summer, which means you've probably kissed math class goodbye. But, there's one calculation you should still be doing: determining your sweat rate. No worries. There's no heavy duty math involved. Just hit up powerbar.com's sweat rate calculator (screen shot at right).
All you have to do is weigh yourself before and after a workout, note the volume of any fluids consumed during activity, and enter the values in the corresponding boxes online. The calculator generates your sweat rate along with a recommended amount of fluid to consume to stay within your hydration zone.
Another way to assess your hydration status is to check the color of your urine (use this chart to compare). Gatorade Sports Science Institute senior scientist Dr. Kim White provides this tip: "If your urine is really dark, like apple juice, you are dehydrated. If it's light like lemonade, you're hydrated. If it's clear, you're over-hydrated. You want it to be a very light yellow color."
Staying in the know about your sweat rate and hydration status are keys to dodging dehydration's nasty side effects—e.g., dizziness, nausea, fatigue—which can put you on the couch instead of in the weight room.