Actually, carb loading as practiced by most is a fallacy. Frankly, it leads to a bloated, rock in the tummy or worse feeling in the race. Eating a couple days of carbs is just not going to help. I am not saying do not go out and have a nice pasta meal with friends and family, just keep the portions in moderation and only eat what you know you can handle well. Practice a good and balance diet through the week and have a light and carby meal (snack) Saturday night before coming over to the race.
What I try to get my runners to do if work up hydration. For the W&D, start on Thursday adding a glass or two of water to their normal intake. Your goal is to pee clear or slightly colored.
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As back ground, carb loading was (and still is among some) practiced by marathoners but one must deplete prior to the loading. So about a week out from a marathon, runners will stop eating carbs while amping up 2-3 workout intensities in an effect to hit rock bottom; carb tank is empty condition. If you want to practice this, head to the gym and work legs until you feel dizzy and like puking (or do so); this is signal that your body is operating in a carb depleted condition& it is not pretty or fun. Personally, I have to have a coach/trainer standing over me pushing to get there. Once depleated, carb loading occurs where the percentage of carbs is increased a few percentage points above normal. After a couple days of loading, runners will then pull back to a balanced diet for the last 3-5 days before the race.
Fat loading is a relatively new concept and one that I find intriguing and that I practice or a week long cycle event or the Goofy/Dopey weekend. Its not what one would think. In real simple terms, the process is only adding 5-10% of additional fat to your daily intake for a 2-3 day period and then through the race(s). I am not talking adding a couple Bacon-ator Half Pounders, or a huge prime rib meal on race eave; rather, focus on the good fats. An extra serving of almonds, a double dose of peanut butter, humus and veggies for a snack. The concept is simple. If one is well trained and running at an effort where fats are the primary source of fuel, a diet that has a sudden and higher quantity of fats will make them more readily available to the runner on race day. The fats that create issue are the same fats that I would try to avoid on most days anyway.
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With regards to Pre-race and during race fueling, go with what you know. For many, Stingers work when other fuel sources fail. I would not feel bad about taking stingers about 20 minutes prerace (with water). Pretzels are old school marathon food. The carbs are fuel and the salts are electrolytes. I would not change at this time as you may be the one who has a bad reaction to pretzels on the run. What I would expect the first time one tried them is a really, really dry mouth and having difficulty getting them down. It is easily overcome, but will take a little trial and error.
As always, you are the voice of reason...even if that voice contradicts everything else I read!
No worries, though, going to stick with what I know. I have a 10 miler this weekend, so I'll take my Stingers with me and be done with it. I was too anxious to eat much more than a few bites of a turkey sub last year, so I think it'll be the good old tuna/pasta salad around 5pm and a Clif bar around 8:30-9pm. Hydration is definitely not an issue. I train in this south Florida heat all year long so if I drank anything more than I already do, I'd probably float off to Cuba.

With regard to the knee& Not such good news. I have iced and rested for the week. I am tempted to head out the door in the morning, just looking for reasons to not run like I still wince with little notice as I walk.