Four steps to perfect marathon fueling (Read 873 times)

There is no right answer for GU, and no matter how much you take, it won't be enough at a full marathon effort or harder. If you take too much, it will sit in your stomach and make you sick.

My gu plan is more based on what I've practiced on some longer runs than reading the instructions. I know I can't handle one but every 7-8 miles or so, otherwise I just get a big gut bomb.

... It's impossible to replace every calorie that you burn while you are still working out. Thankfully, there's no need to. ..

Really all you want to do is take on the minimum number of calories required to keep from fully depleting your glycogen stores, or bonking. Any more than that is wasted during the run and could cause other complications like stomach cramps etc. There's plenty of time after the race for replenishing. That's not what fueling on the run is about. How much you need to take in is highly dependant on your pace. If you're running at a relaxed and easy pace with a goal of simply finishing, you probably don't need to take on any calories--at those paces you're burning carbs to fat in about a 50/50 ratio and you have plenty of fuel stored to run well over 26 miles. The problem is that, for most of us, marathon race pace burns glycogen at a much faster clip than easy running so if we don't take in some sugar on the run, we'll bonk. This is exacerbated by the fact that going out just a tiny bit faster than race pace burns glycogen even faster and significantly reduces our fuel window. This is why aiming for a positive split and trying to "put some time in the bank" is usually a really bad idea.