When you’re dripping with sweat after a workout, it’s natural to want to gulp down a full bottle of water, especially if it’s ice cold. However, if you’re feeling a strong thirst during and after exercise, there’s a chance you’re already dehydrated. Where’d you go wrong?

Hydrate before you exercise

Nope, this doesn’t mean you should be consuming a liter of water right before you hit the treadmill or the weight bench. Consuming too many liquids right before a workout will leave those liquids sloshing around in your belly as you exercise, causing distraction and discomfort.

Instead the American Council on Exercise (ACE) recommends finishing 17 to 20 oz. (that’s 500-600 mL) at least two hours before you begin working out, and then another 8 oz. (just under 250 mL) a half hour before you get moving. This way, you’ll start your exercise knowing dehydration isn’t going to limit your performance.

Sip as you move

Some forms of exercise don’t lend themselves to convenient stops for rehydrating, but chances are there are built-in opportunities to take a sip or two during your workout. Keep your water bottle close by so you can drink small amounts throughout the workout without interrupting your flow.

Refill your tank in moderation

The ACE suggests that you take in an additional 8 oz. of water within 30 minutes after completing each workout to replace the fluids lost through perspiration. Again, this is just a moderate amount, since you’re probably still cooling down, and introducing too much water to your body right away might not feel like a great idea once you’ve done it! For athletes with specialized hydration needs and folks who really work up a sweat, you’ll want to continue rehydrating for the next couple of hours, though for most people your regularly scheduled water intake should be enough.