Week 12 of 14 (Part 2) - Carb Depletion

Since posting yesterday's summary of Week 12 there have been several questions about what sort of nonsense thinking is involved in doing a carb depletion this week as opposed to the more usual marathon routine of final week carb depletion/carb loading?

So, instead of answering the same question more than once, this is the nonsense thinking employed:


Carb Depletion followed by Carb loading:

Carb depletion followed by a carb loading period used to be the modus operandi for years but then fell out of favour because of the bloated feeling that people were experiencing on the start line as well as doubts about whether carb depletion actually did any good.

The theory on the carb depletion was that it would make the body hungry for carbs and lead to a super compensation effect when carbs were re-introduced. The thinking was was that this would lead to a greater capacity for energy storage for the start of the marathon.

However, despite plenty attempts there has been no evidence to suggest that any super compensation effect actually exists at all.

The chances are that it doesnt, you have a certain number of mitochondria as a result of the training, each with a certain capacity for fuel storage, it isnt very likely that a carb depletion/carb loading routine is going to do much to change that total storage capacity.

So that leads to two questions:
a) Is there any point in carb loading?
b) Is there any point in carb depletion?

a) Carb loading -  There isnt much doubt that most runners really overdo this aspect. Normal eating will get carb stores filled up, especially with minimal exercise going on at the same time. Because carbs attach to water molecules, it isnt surprising that piling excess carbs in leads to an uncomfortable bloated feeling. If the body is giving off discomfort feelings then surely it is trying to say something?

b) Carb depletion - If carb depletion doesnt cause a supercompensation effect then why bother with it at all? On the basis that I have always felt stronger and rejuvenated in some way after a carb depletion I am convinced it is a beneficial process for some reason. What that reason is doesnt really matter but it is entirely possible that leaving carbs out of the diet for 3 days forces you to consume nutrients that may have become a bit deficient during the weeks of training. Getting these topped up and consuming plenty protein to strengthen muscles and connective tissues seems to be where the benefits are.

And if that is the case, is there any need to leave it until the last week to get strengthened up? If it is going to work in the last week then it is going to work in the penultimate week as well.



It may be way off the mark from what is really happening but because it has worked for me a few times now the Double Carb Depletion approach, without any excessive 'carb loading' is worth pursuing again in my books.  :)

If I crash and burn at VLM it may be time to reevaluate!



Also, because the carb depletion benefit isnt related to storage capacity it doesnt apply just to marathon build ups. Full strength muscles and connective tissues must be a good thing for all race distances, not to mention for injury prevention purposes. I used it to very good effect before last year's GNR and have never felt better