Keep yourself properly hydrated with an ample amount of sports drinks and water during your marathon, as well as your practice marathons. Without proper hydration, running a marathon is like driving around in your car without oil in the engine (except that you’re the car). At some point, your body WILL break down. During your practice marathons, try to gauge how much hydration fluids you will need during the real marathon. Energy gels that contain electrolytes are also lightweight and very effective at keeping you hydrated during your run. It is also advisable to find out how many aid/hydration stations will be on the course. When choosing a sports drink to keep you hydrated, make sure that it includes an ample amount of sodium and electrolytes in the ingredients list. In the days prior to your marathon, drink plenty of water and non-alcoholic fluids. Approximately an hour before you start your marathon, try to drink 16 ounces of water. Stop drinking after that point; you do not want to have to stop for a bathroom break during your run. A great formula for staying hydrated during a marathon is to drink 4 to 6 ounces of water every 20 minutes during it.