Breaking the Wall

Okay Sasha you have to explain this statement

"The idea was to fall asleep burning fats during the run, then speed up without waking up the carb-burning beast."

Kory:

When you run slow you primarily burn fats. As you speed up you switch to carbs. If you could learn to burn fats instead of carbs while running the same pace, your fuel situation improves. When you run slow and then start gradually speeding up the transition to carbs is not immediate, there is a delay. This will give your body maybe a 2-3 minute window of practicing fat metabolism at a quick pace. The pace must not get too quick, this would wake up the carb metabolism and defeat the purpose of the pickup.

You can actually feel it. When you are burning more fats you feel sluggish at a relatively slow pace. Once the carbs kick in all of a sudden the pace feels a lot easier. A good time for this exercise is at the very end of your easy run, about the last mile or so. Make sure the easy run pace is around 7:30, any faster might put you in the carb zone too far. Then in the last mile, very important, do not get worked up about anything, pace, work stress, last night's football game, nothing, you must be absolutely calm, or else the adrenaline will release the carbs and you will not be relying on fats sufficiently. Start speeding up to marathon race pace, or a little slower in a leisurely manner, absolutely do not force it. If it feels too easy, you are probably not doing it right. You must feel like there is a wall that keeps you from going faster. Then in the last quarter if you want to test if the wall was metabolic, not a result of general fatigue/bad day, push a little harder. If everything happened like it is supposed to you'll be able to pick up quite significantly, and it will not feel hard. Once you've learned the feeling, it should not be necessary to do those tests in the last quarter, use it to practice burning fat instead.

This is an interesting concept that has made a splash in the ultra world, as well, when mid-run fueling becomes more and more of a limiting issue. Many ultra runners rely heavily on specially made ultra products that tend to be glorified mixtures of sugars (fast burning carbs), and slightly more complex (slower burning) carbs. I have found (and have been backed up by several more experienced ultra runners) that if I consume a little less food during a run and start just slightly more conservatively, I have much more even energy levels throughout the day. On the other hand, toward the end of the run, if I want a quick boost, I can grab something with a high sugar content to get a quick rush and hope that I finish the race before the ensuing crash.

In any case, I think you are correct regarding starting slow and trying to increase the pace at which you can maintain almost pure fat metabolism as opposed to carbohydrate metabolism, but it can be frustratingly slow at times, and I am the king of going out too fast and flying through training runs under the premise of "train fast, race fast."

I've actually done this on my 20 miler last week. I started out with no food before hand or during the run (no water or sports drink either). I started slow and was very sluggish then towards the end of the run I started pushing the pace and it was hard. But the last little push when I went faster was better.

If we can rely on burning fats in a marathon definitely is an advantage to not lose all the glycogen.

Also running a long run slow is good just to keep your feet out there for along time to build endurance and not really worry about the pace.