I'm going to go ahead and let you guys know that I'm not a pro on this stuff. I'm brand new (kinda) into this world, and so this is all things that I've had to learn along the way, but I thought that I would share some helpful insight to get you started on how to take care of your bodies when you are pushing it to limits that you normally wouldn't do.
1. TRIAL AND ERROR
This is honestly the biggest thing. I will get into the details of what to even try but everyone is so different and what works for me may not work for someone else. Before a marathon, you should utilize each and every long run to test your nutrition the night before and the morning of to see how your stomach responds. You can adjust this through training so that the day of the marathon, you aren't constantly running to the porta potties or worse, not being able to finish because of dehydration, gut pain, etc.
I think this is a no brainer obviously but the day before a long run or the day before a race, you need to be drinking lots and lots of water. It's not going to help you if the morning of a workout, you chug a lot of water. It needs to be something that you have done the day before so that you are hydrated up.
During a race, there is always going to be water stations for you to stop at. They always say that if you pinch the top of the cup then the water can slide into your mouth without splashing all over you. That's not my forte. It always goes all over my face. I normally stop, walk like two steps to chug, and then start running again. It's not going to hurt your time, and it's going to help you to get water in.
During your training runs, if you don't like to carry water (like I don't), then I would recommend a route that has water stops along the way even if it's a bathroom faucet (I've done this before haha). If not, then you could even go with your car and set up water beforehand. If it's a 16+ mile run and you are not intaking something along the way, then you are really wrecking havoc on your body and you really should consider changing that. I was stubborn about this for awhile until I have read stories of people dying from this. It's no joke folks.
3. DON'T FORGET ELECTROLYTES.
When you drink too much water, you can actually flush out some of those electrolytes on top of the fact that you are going to be losing a lot of fluids. You have to be DILIGENT about this because this is where you can run into trouble. Many people will chase salt packets with water the morning before runs. I personally just take a salt tablet that you can get online. I also use COCOGO which in all honesty is an amazing product (y'all know I won't promote one supplement I don't think is worth it). For example, Gatorade has sodium and potassium which you need but cocogo has triple the amount of potassium, more appropriate sodium amounts, calcium, less sugars, and magnesium (which is an electrolyte that most sports drinks tend to forget). So, obviously I really stand by this product (which I did not use before my half and I normally do sooooooo there's that).
I promise this isn't my little plug, but if you do want to try Cocogo then you can use KATIESFITSCRIPT when you check out for 10% off, and everyone loves a discount.
Gus and gels are vital in those long runs and you have to be on top of it. This is all a learning process. I've learned that if I'm doing a training run of 12 miles and below, I don't really need a gu. However, if I'm doing something more than that, then I take a gu about halfway through and it really helps me to finish strong. During my marathon, I used 3 spaced out evenly and then I ate candy along the way. You are depleting lots and lots of glucose and you want to make sure that you are on top of fueling your body before it gets depleted because then it's going to take time to get back to normal. Gus and gels also have electrolytes as well! This is why they are better than just candy (however candy is better than nothing).
5. CARB LOADING
The night before you always hear about the carb load. I honestly am somewhat against this. I believe that you should definitely eat more the day before. However, I don't agree that you should just stuff your face with unending amounts of pasta because you are going to feel heavy and like crap the next day. As always, test out different things the night before your long runs. I like to have a big bowl of oatmeal extra right before I go to bed to have some long digesting carbs through the night. I normally make sure to have a heavy carb dinner as well, but I stop when I'm full and don't just stuff my face.
6. BREAKFAST THE MORNING OF
I think that a great breakfast is oatmeal like I said I have the night before, and then a banana right before the race. This way you are getting the slow digesting carbs in the morning, and then the banana for that extra sugar right before you go. You also are going to be taking gus along the way so that's going to keep that constant stream of glucose.
I think that you can see that carbs on carbs on carbs is very vital during training and race day nutrition. Make sure to drink separate from the food that you eat, so that your food can be absorbed better. Basically, you should have a water bottle with you at all times during marathon training and then make sure before those long runs to not forget about electrolytes and you should be good.
The first time that you experience the "gut pain", you will never forget it. I've had it in the past but never as bad as this half marathon, and I will know from now on how diligent I need to be about this stuff!
I hope that this helps you fuel a little better for your races.
With love and fuel,