We often focus on hydration during training for a marathon, but then for some reason, sometimes that focus gets thrown out the window at race time! Listen to RunnerDude... Don't Do That!
Hydration can make or break a race for a runner. You can be carbed -up to the max, have trained your body to better utilize its fat stores, and have increased your endurance 10-fold, but if you get dehydrated during a race, it may spell DISASTER for you.
Here are a few things to keep in mind to make sure you're well hydrated before, during, and after the marathon.
1.Find out what sports drink will be provided during the race. If you're able, train using the same sports drink provided by the marathon. If your system doesn't tolerate the featured race drink or you'd just prefer to use something different, be sure to plan out how you'll carry or have access to your preferred hydration source. Some options include, wearing a hydration belt or stakeout family members or friends along the course ready to hand you your preferred fluids.
2.Never use the featured sports drink in a Marathon, if you did not use it in your training.Don't Do It! This will often cause stomach issues. The many different brands of sports drinks available contain varying amounts of carbs and electrolytes. Some contain other components such as protein. If you've not tried these products during training, you don't want to risk causing stomach issues on race day.
3.Don't over hydrate. Throughout the day before the race, drink water when you are thirsty, but don't overdo it. Drinking a half a cup to a cup (4-8 oz) each hour works well. Remember, you'll still be carb -loading on this day. Make sure some of your carb intake includes salty simple carbs like pretzels. Also eat a banana or two for the potassium. This will help ensure that you're not flushing out your precious electrolytes that you'll need during the race. Do not drink alcohol the day before the race. This can dehydrate you.
4.Drink 16oz of water 2 hrs before race time. This will provide enough time for the water to pass through your system and the excess be voided well before the start.
5.During the race, drink 6-12oz every 15-20 minutes. Don't rely on the Thirst Mechanism during a race. By the time you are thirsty you are probably already dehydrated. When you are severely dehydrated, you may not even experience thirst. Water works fine the first 45-minutes of the run, but after that sports drinks should be used to help restock the body's glycogen stores as well as replace electrolytes that are being sweated out. Whether you drink water the first 45 minutes and then use sports drinks or you use sports drinks the entire race, make sure it's what you did during your training. Don't vary on race day!
6.Rehydrate after the race. Do a "Sweat Test" a couple of times during your training. Simply weigh yourself (in the buff) before a long run. Do the run. Weigh yourself again (in the buff) immediately after the run. The weight loss incurred is the amount of water you sweated out. For each pound lost, drink 16oz of sports drink. Drinking sports drink will help replace the lost carbs and restock your depleted glycogen stores as well as replace lost electrolytes. This will help ensure a better and quicker recovery. It's important to remove your clothes before weighing especially after the run. If you sweat heavily, your wet clothes could be adding weight which will keep you from getting an accurate post-race weight loss total. Doing the Sweat Test a time or two during your training will give you a good idea as to how much you'll need to drink to rehydrate after a race, since you probably won't have access to any scales until quite a while after the race.