.

During my series on physique assessment last week I mentioned that one of the key elements of creating a vastly more aesthetically appealing body is to get your waist as close as possible to an ideal size (which I defined as approximately 45% of your height).

 .

I later received an email asking if I believed it was possible to preferentially target abdominal fat as was mentioned in THIS ARTICLE.

 .

Truth be told, I have a great deal of respect for Dr. Lowery and generally appreciate his articles so this is not an intended slam on him personally or T-Nation for posting the article.  However, I’m just not convinced at this point that the main study supporting his article was strong enough to suggest that this is really an effective strategy.

.

Let’s Take a Look

.

Are blood flow and lipolysis in subcutaneous adipose tissue influenced by contractions in adjacent muscles in humans?

Stallknecht B, Am J Physiol Endocrinol Metab. 2007 Feb;292(2):E394-9. Epub 2006 Sep 19

.

Background

.

There is evidence that exercise induced fat loss is higher in visceral fat (around the organs) and subcutaneous adipose tissue (fat below the skin) in the abdominal region than in the femoral (thigh) region.  This suggests that regional fat tissue is regulated independently and that spot reduction may be possible.

.

*Note that the aforementioned belief belongs to the authors not me*

.

Numerous studies have examined spot reduction with conflicting results.

.

Purpose

.

To determine if spot lipolysis (local fat breakdown) in subcutaneous fat occurs to a greater degree overlying contracting muscle than resting muscle.

.

Methods

.

10 male subjects performed one legged knee extension ergometer for 30 minutes at 25% of their maximum work capacity.  They then switched legs and performed 120 minutes at 55% of their max work capacity.  Finally, they switched back to the first leg and performed another 30 minutes of exercise at 85% of their max work capacity.

.

During this time they had microdialysis catheters inserted in the adipose tissue of each thigh to measure blood flow and fat breakdown.

.

.

Results

.

In general, exercise increased adipose tissue blood flow in both the working and resting leg.  However, in the 25% and 55% work capacity conditions, the blood flow to the adipose tissue closest to the working muscle was higher than the resting leg.

.

.

Subcutaneous adipose tissue lipolysis (fat breakdown below the skin) was greater for working leg in the 25% and 85% capacity groups, but not in the 55% capacity group.  In other words, the fat breakdwn for both the exercising leg and the resting leg was the same in the group working at 55% of their work capacity.

.

.

My Thoughts

.

One major point that I want to highlight is that Dr. Lowery correctly pointed out that exercise does increase body temperature and temperature does increase adipose tissue blood flow.  However, based on this study, I’m not sure the blood flow and lipolysis are even directly releated..

.

In the 25 and 55% conditions blood flow was higher for the exercising leg, but adipose tissue lipolysis was greater in the exercising leg in only the 25 and 85% conditions.  In other words, the conditions that caused the greatest increases in blood flow didn’t match the conditions with the greatest amount of breakdown. 

.

As a result, I tend to believe temperature and blood flow may not be the primary mediators of local fat breakdown.  So even IF local fat breakdown can be effected, taking measures to increase local temperature and blood flow probably aren’t going to help.

.

And, as the authors of the study astutely pointed out, any broken down fat stores may be replaced or even supercompensated (more fat stored there) when exercise is complete.  This is certainly a possible scenario and highlights the importance of not using acute variables (like lipolysis) as anything more than hypothesis generating tools for the possibility of chronic changes (like local fat loss).

.

But most importantly, even if the fat wasn’t replaced in that area, the maximum calculation for the amount of fat lost in the area at the end of 30 minutes of 25% or 85% exercise is 2.1 milligrams of triglyerceride per 100 grams of fat in that area.  Doing some rough calculations in my head I think this would amount to NOT VERY DAMN MUCH!!!

.

 

As I’ve blogged before, I just don’t think the evidence for spot reduction is strong enough to warrant any of the methods suggested to achieve it.  And even if it was statisticaly significant, will it be visually relevant?  Would you really notice these effects in the mirror?  Two milligrams per 100 grams of fat doesn’t seem like it is worth pursuing to me.

.

What do you think?

.

If you’d like to review studies like this for yourself, check out my product How to Read Fitness Research.