(If you are reading this blog, then you probably already run and you know what I'm about to tell you. In fact, you probably know more than me! )
There are so many choices for running food.
Some of the most popular fuel for a long run include gels (you can buy them at running, biking, hiking or sporting stores), bars (these are more widely available. I've seen them at Target, grocery stores, and the stores listed for gels), blocks (a gummy textured almost candy like food found in the same locations as gels. Honestly, I have to fight to keep my kids from eating all mine.) even sport beans (think Jelly Belly's with a kick).
Before a race or a long run I usually stick to foods my body is used to. I ate oatmeal without any ill effects for years, but I switched over to a pb&j about an hour before and a banana about 15 min before. I most likely made the switch one morning when I wasn't prepared and didn't have any oatmeal in the house. I can't recall. I know that I have been using pb&j's as a pre-run fueling source for many years.
(M grabs a cliff bar on his way out the door and eats that before a run. Or whatever extra bar I happen to have available.)
I'm really bad at remembering to eat early in a race. I'm usually too caught up on making sure I don't fall on my face, or miss a turn, to remember to eat. In trail running I find that eating early and often is the key to not hitting an unfortunate low. You can dig your way out of a low, but it's usually a long hard battle. It's better to nip it in the bud before you get there. Most runners call that low 'hitting the wall.' Depending on your training, the wall is a variable you can work to avoid with proper fueling. But, the longer you run, the more likely you are to hit your wall.
When to eat
Most recently, during a 50 mile race I consumed dates, watermelon slices, boiled potatoes (occasionally dipped in salt), a Pro Meal snack bar, 2 double espresso shot gels, a cup of soup, a particularly delicious mini candy bar, coke and lots and lots of water. I often carry bacon (yes, you read that right, bacon) for a race (and loads of other runners usually ask for some!). During a 22 mile training run up in the mountains we talked a hiker into passing off her canister of chips, and everyone dove straight into them! If you find yourself craving salt, have something on hand to satisfy the craving. I usually tailor my food for my training runs on what I find appealing during a race or whatever I'm currently craving. One training run I craved a slice of Costco pizza the entire run. I couldn't figure out a way to have it on hand though, so l learned to live without it. (I was honestly trying to figure out if it was feasible to have a frozen slice in my drop bag for the aid station at mile 22.)
I'm really bad at remembering to fuel my body after a run. I'm usually in my car and off to relieve my husband from kid duty. I recommend sticking something in your car you think you will be able to tolerate after running. Lots of friends drink chocolate milk, an easy and yummy source of protein. If you have the luxury, go out for breakfast and eat something with protein. If you think to can eat another one after your run, have a protein bar. (There's a trend.... protein!) Protein helps speed muscle repair and aids in recovery. Try it. You will probably feel better after a hard run!
Ultra aid stations are amazing. They are run by ultra runners who are giving back to their friends and fellow trail mates. They usually ask runners they know running in the race what kinds of treats they might like to have on hand. Mainstays of an aid station include water (duh), electrolyte drink, potatoes, chips, pretzels, m&m's, mini candy bars, orange slices, pb&j sandwiches, coke, ginger ale.... you get the idea, you won't starve. But if you don't see something you had your mind set on, ask, you never know.
If you feel like playing around and experimenting, I suggest making your own running food.
One of my particularly favorite books is The Feedzone Portables (http://feedzonecookbook.com/portables/). The food it's delicious and wholesome. Unfortunately it's time-consuming to make and the portions are large. The few that I have tried were easy on my stomach and provided long lasting energy. More experimentation will have to be done with this book in the future.