It's been interesting what I've learned over the course of running shorter distances to going longer distances. I'll break this blog into two, the first section is about eating properly before, during and after.
When you run 4,5,6,7,8 miles you can typically go without having to eat a breakfast before you run (at least an hour and a half before you run). As you stretch out and go longer 9,10,11,15,20 it's important to bring things to "snack" on during your run. Before you go to run, you should eat something, I typically chose a bagel toasted and I put peanut butter on it and I'll eat that. I'll head down an hour later and go to the park and start my run (takes me around 30 minutes to get to the spot in the park where I run).
From there you should remember to bring some kind of gels or power blocks with you. You will probably only need a couple but make sure to bring water. These gels like Cliff Shot Energy Gel or PowerBar Gels are good for you to run, and will make you feel energized as you hit your wall. You need to take these gels with water. My coaches recommend you try a few during your practice runs so you know which ones you like prior to your race day. Some are kind of gross and can make you gag a little, but remember this isn't to be in place of a meal rather it's meant to give you a boost in energy and keep you moving ok.
After you are done you have what they call an optimum time to eat. 30 minutes after your workout your body burns calories at the highest rate so that's the time to eat. Even if it's another bagel or something it will recharge you and you'll burn it off pretty fast (pretty cool huh?).
So I'm a bit of an odd duck when it comes to water. I hate drinking LOTS of water. I don't like the fact it's kind of tasteless. It's my hang up! Ha! In any case if you know you are doing a half marathon I recommend you start hydrating at least two to three days before your race. The reason is you are going to run 13 miles so you will need to have that water moving your body to keep you going. Guess what. You will sweat a lot. SO HYDRATE. If you are going to run longer runs, it's recommended you invest in a water belt. You can find these at most running stores for around $45.00. Some come with a pouch to hold your wallet or identification or your power gels/power blocks as well.
I hope these tips help! Keep moving, hydrate and fuel the body that keeps you moving. Remember every step of step, mile over mile takes energy so give your body the most energy it can and it will carry you!