To make sure that your run is a more enjoyable experience, you want to make sure that you're hydrating properly for that activity. To make sure you're getting enough fluid before your run, try to have about 20 ounces of fluid at least an hour before your run. If you find yourself a little thirsty, take small sips, but you don't want too much fluid in your stomach. If you're running and you start to feel or hear the water sloshing around, you know you're well hydrated enough, so you don't need to take in anymore fluid at that point. But while you're running, feel free to take stops at your local water fountain.
Maybe you're carrying a water bottle with you, or a fuel belt. There are fuel belts available that actually have small water bottles in them so that you can carry hydration packs with you. You can find a Camelback, maybe a North Face backpack that has the bladder inside that you can slowly take sips during your run. But if you're going for a long run, especially on a hot day, you do want to make sure that fluids are available for you.
Try maybe a sports drink if it's a hot day or if you're going for a long run, something with a little bit of electrolytes to replace the sodium that your body's losing through sweat. There's a lot of great products out there, there's Gatorade, there's Heed, there's Excel, there's Hammer. Take a look at your local running store or maybe follow some forums online to see what other people are using.
Try to experiment, see what works for you, see what works for your body. Some things upset peoples stomach. Try to find something that doesn't upset your stomach so that you can continue running throughout your workout. After your run, you want to make sure that you're hydrated. If you're not taking in fluid during your run, make sure that you rehydrate after your run. Maybe you've only for 20 or 30 minutes, maybe up to 40, but usually the general rule of thumb is about 40 for 40, 40 ounces for 40 minutes.
If you're hydrating during your run, continue to take fluids in throughout the day. If you're not sure how hydrated you are during the day, pay attention to your urine. The color of your urine is a really good indicator to see how well you're taking in fluids throughout the day. If it's a light straw color, it's usually a good sign that you're hydrated. Pay attention after your run. How dark is your urine? Maybe you didn't take in enough fluids during your run. Make sure you're taking in fluids throughout the day, and stay hydrated.