Monday, January 26, 2009

Fasting and GH

This is quite an interesting video from Brad Pilon.





Growth hormone or 'GH' is a very important hormone that regulates the release of fat from your body stores so that it can be used as a fuel source.

Traditionally we have been taught that to burn fat you need to keep our insulin levels 'normal' or 'under control'. It turns out that the release of body fat is controlled by GH....

Intermittent fasting of course increases GH levels as explained here

I like Brad's eat stop eat book on fasting which explains this among other stuff..

Lots of us in the paleo / evolutionary fitness community are regularly practising fasting. Richard often fasts as does Keith - pictured below.





Keith - in this post explains how fasting has added the finishing touch to his physique:

Essentially, we are designed to be intermittent eaters, but continuous metabolizers. We operate in a slight energy surplus during the day, followed by a negative energy balance during the night. In a healthy, lean individual, energy pool stores are constantly turning over; individuals whose insulin level is chronically high, however, cannot adequately access fat stores and, therefore, for them, the fat continues to accumulate, unabated. Insulin resistance can therefore be considered a survival mechanism, in the fact that it develops as a result of the body’s cells’ requiring protection against the continual onslaught of excess nutrients; a protection triggered due to the cells being already stressed from excessive nutrient content. The excess nutrient intake also serves to shut down autophagy, the consumption of damaged tissues within the muscle cell which fuels repair and regeneration. Growth Hormone release is stunted, and muscle gene expression is down regulated. The ancestral environment did not support chronic, elevated nutrient ingestion, nor was there ever “a window of feeding opportunity” subsequent to a bout of energy expenditure (exercise, for us modern-day Paleolithics) to shovel in carbohydrate replacement drinks and protein powders.


Ideally, we’d eat only when the energy substrates in the blood fall to the point of triggering a need for replenishment. The true hunger signal is an elegantly simple energy management system, and one that you would, in fact, expect from evolution. Contrary to the continual drumbeat of mainstream “experts”, there is no “set point” level for body fat, body mass or metabolism. What evolution has endowed us with is a simple feeding strategy that endeavors to keep us on a random energy intake-to-expenditure path that favors the survival (and thriving, if conditions are right) of the organism. Now, if we’d only get out of the way and let this fabulous mechanism take its course.

Brad's book is a great introduction to the science behind all this.

7 comments:

Sue said...

So does intermittent fasting encourage the release of Growth Hormone? As would resistance training.

Chris said...

Hi Sue

it certainly does. I had a post on this way back on 2007.

the full text of the study is linked.

In conclusion, the present data suggest that starvation-induced enhancement of GH secretion is mediated by an increased frequency of GHRH release,

Anonymous said...

A short-burst, high-intensity workout, while in a fasted state, is, IMHO, the silver bullet for loosing that final, stubborn bit of body fat.

Chris said...

Keith

that is interesting. Lyle McDonald's Stubborn Fat Solution protocol is built on similar ideas - referred to on the blog somewhere. Although he'd have you do some standard cardio after the intervals. The intervals liberate the fat then the cardio burns it.

Anonymous said...

So, when is the right time to fast? And for how long is the fast? And how frequently is the fast done?

Thank you kindly.

Chris said...

Anon

There is lots on this site on fasting. Check the tags for IF or intermittent fasting.

Mike T Nelson said...

Great stuff here! I just found your blog and awesome job!

In relation to high intensity cardio releasing more fat, there is some research done in the mid 90s (perhaps there are newer studies) that shows BURNING the fat is the limiting factor NOT releasing it into the blood stream.

Again, it is always hard to say for sure, and in what population, exercise mode, training age, etc.

Keep up the great work!
Mike N