Saturday, April 12, 2008

New Study--Insulin, Exercise and Metabolism

New study time!

Here is another study talking about nutrient timing.

Effect of timing of energy and carbohydrate replacement on post-exercise insulin action
Stephens BR, Sautter JM, Holtz KA, Sharoff CG, Chipkin SR, Braun B.
Appl Physiol Nutr Metab. 2007 Dec;32(6):1139-47

The concept has been around for a few years now and it underscores the importance of WHEN in addition to WHAT you eat.

In general, exercise enhances the body's ability to use insulin. Insulin is a storage hormone and is most often mentioned in the storage of excess fatty acids into fat cells (yes, adding to your "muffin top"). Controlling insulin may help your fat loss progress then. While this is a drastic over simplification of many many processes, better insulin sensitivity is viewed as a good thing. A way to increase this is to exercise! Score another one for exercise.

The interesting part about this study was that they took subjects and reduced their insulin sensitivity and then determined the effect of exercise. They concluded that a bout (singular) of exercise enhanced insulin even when carbs and protein were replaced. So, even if you burn 200 calories and then replace them with 200 calories, your insulin sensitivity should still be better than if you never burned them at all. Further evidence that movement/exercise is good for you!
They mention that lean, health subjects that they put into a temporary state of insulin insensitivity may still keep a high level of "metabolic flexibility"; so they can "recover" with less exercise than some who possess less metabolic flexibility. If you are interested in metabolic flexibility, see my review on it.

We don't need more evidence to show that exercise is good for us, but it does shine light on the mechanisms that may be happening.

If you have enjoyed this, I need to thank Alan Aragon for reviewing this study in his first Research Review that he puts out. In it he reviews several studies and provides awesome insights into each. I highly highly recommend you check it out by clicking here. It is WELL worth the 10 clams a month. I get ZERO money to say this and make no money off of anyone that signs up at his site. He does a great job of doing all of the "leg work" for you!