Monday, September 14, 2009

The Endurance Athletes Guide to Nutrition – Part 3: Physiological Processes

Blood Glucose Levels (BGL)

Because fat and protein generally take a long time by your body to breakdown into usable energy, and because they don’t trigger an insulin spike, your BGL is kept steady while digesting and processing these types of food.

Carbohydrates on the other hand, are broken down much faster which will raise your BGL. When your blood sugar level is raised, you release insulin and cortisol to help regulate the spike in BGL. Cortisol is actually a stress hormone, and insulin, or lack of, is partly responsible for adult onset diabetes.

Now as for effects of specific carbohydrates on your BGL, this is documented in the Glycemic Index, and Glycemic Load. Sugar, as you can imagine, ranks near the top. For a full list, check out this or that to find out what carbohydrates will reduce the spiking in your BGL.

It should also be noted that your BGL (and resulting physiological processes) are what’s responsible for “the crash.” The crash is from fueling your body up with all this energy, and then doing nothing with it. Remember back when everyone thought they got tired after eating a huge thanksgiving dinner because of the tryptophan in turkey? Well, it was from gorging themselves with everything under the sun and our bodies were basically saying “NO MORE!” and shutting us down to prevent us from eating anymore.

Oxidative Damage

I wrote another article a while back on anti-oxidants, which seems to get a lot of attention these days from the media - and for good reason.

When we exercise, a lot of things happen. For starters, the oxygen we inhale reacts with chemicals in our body, some of which are used to produce the energy we use to train. Oxygen, as vital as it is to life, is a very reactive molecule, and is partly responsible for creating free radicals in your blood stream. Free radicals are responsible for a number of things - including causing cell damage, stress, and pre-mature aging.

When we train and race, especially long distances, we are inhaling about 10 times more oxygen than what we do at rest, so there are A LOT of things happen at the cellular level. With the huge increase in oxygen, comes a huge increase in free radicals. As I will cover in the next part, anti-oxidants should play a key role in your endurance training to help minimize the damage done by training. The simple rule of thumb is to eat an absurd amount of anti-oxidants (on the order of 10,000-20,000 ORAC units per day). For a listing of ORAC amounts in foods, check out this link.

Anti-oxidant supplements

Although supplements could be an entirely new subject or article, it is worth touching upon supplements, specifically in the form of anti-oxidants.

Personally, I don’t believe most people need supplements - regardless of how much marketing there is, and how much supposed performance gains may be achieved. However, as endurance athletes who continuously push our bodies’ limits, taking a multi-vitamin, or anti-oxidant supplement is probably worthwhile. There are a number of things you could take – from the standard multi-vitamin or anti-oxidant pill, to nano-greens to lipoic acid to damage control master formula. You really have to decide what price range you are comfortable with. However, I will note that buying vitamins that have 1000% or other really high % of RDA is hardly necessary. The good thing is that there are quite a few vitamins that are considered anti-oxidants, such as C, E and parts of A - and these you always get in a multi-vitamin.


• Keep your BGL steady for the best short and long term health
• BGL is primarily governed by the foods you eat
• Endurance training increases free radicals the body, which can lead to premature aging, stress and cellular stress.
• Eat a diet rich in anti-oxidants
• Supplements as necessary

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